Remove the error return value and instead just throw error

And write a few tests for it

.vscode/launch.json

@@ -98,6 +98,19 @@
 			"args": [
 				"cook_tacz.yml",
 			]
+		},
+		{
+			"name": "Launch Package (ICARUS)",
+			"type": "go",
+			"request": "launch",
+			"mode": "auto",
+			"program": "${workspaceFolder}",
+			"cwd": "C:/Users/Administrator/Seafile/Games-ICARUS/Icarus/Saved/IME3/Mods",
+			"args": [
+				"-loglevel",
+				"trace",
+				"cook_processorrecipes.yml",
+			]
 		}
 	]
 }

README.md

@@ -16,6 +16,7 @@ A Go-based tool for modifying XML, JSON, and text documents using XPath/JSONPath
   - String manipulations
   - Date conversions
   - Structural changes
+  - CSV/TSV parsing with comments and headers
   - Whole ass Lua environment
 - **Error Handling**: Comprehensive error detection for:
   - Invalid XML/JSON
@@ -101,6 +102,87 @@ chef -xml "//item" "if tonumber(v.stock) > 0 then v.price = v.price * 0.8 end" i
 <item stock="5" price="8.00"/>
 ```
 
+### 6. CSV/TSV Processing
+The Lua environment includes CSV parsing functions that support comments, headers, and custom delimiters.
+
+```lua
+-- Basic CSV parsing
+local rows = fromCSV(csvText)
+
+-- With options
+local rows = fromCSV(csvText, {
+    delimiter = "\t",        -- Tab delimiter for TSV (default: ",")
+    hasHeaders = true,       -- First row is headers (default: false)
+    hasComments = true       -- Filter lines starting with # (default: false)
+})
+
+-- Access by index
+local value = rows[1][2]
+
+-- Access by header name (when hasHeaders = true)
+local value = rows[1].Name
+
+-- Convert back to CSV
+local csv = toCSV(rows, "\t")  -- Optional delimiter parameter
+```
+
+**Example with commented TSV file:**
+```lua
+-- Input file:
+-- #mercenary_profiles
+-- Id	Name	Value
+-- 1	Test	100
+-- 2	Test2	200
+
+local csv = readFile("mercenaries.tsv")
+local rows = fromCSV(csv, {
+    delimiter = "\t",
+    hasHeaders = true,
+    hasComments = true
+})
+
+-- Access data
+rows[1].Name  -- "Test"
+rows[2].Value -- "200"
+```
+
+## Lua Helper Functions
+
+The Lua environment includes many helper functions:
+
+### Math Functions
+- `min(a, b)`, `max(a, b)` - Min/max of two numbers
+- `round(x, n)` - Round to n decimal places
+- `floor(x)`, `ceil(x)` - Floor/ceiling functions
+
+### String Functions
+- `upper(s)`, `lower(s)` - Case conversion
+- `trim(s)` - Remove leading/trailing whitespace
+- `format(s, ...)` - String formatting
+- `strsplit(inputstr, sep)` - Split string by separator
+
+### CSV Functions
+- `fromCSV(csv, options)` - Parse CSV/TSV text into table of rows
+  - Options: `delimiter` (default: ","), `hasHeaders` (default: false), `hasComments` (default: false)
+- `toCSV(rows, delimiter)` - Convert table of rows back to CSV text
+
+### Conversion Functions
+- `num(str)` - Convert string to number (returns 0 if invalid)
+- `str(num)` - Convert number to string
+- `is_number(str)` - Check if string is numeric
+
+### Table Functions
+- `isArray(t)` - Check if table is a sequential array
+- `dump(table, depth)` - Print table structure recursively
+
+### HTTP Functions
+- `fetch(url, options)` - Make HTTP request, returns response table
+  - Options: `method`, `headers`, `body`
+  - Returns: `{status, statusText, ok, body, headers}`
+
+### Regex Functions
+- `re(pattern, input)` - Apply regex pattern, returns table with matches
+
 ## Installation
 
 ```bash

example_cook.toml

@@ -0,0 +1,119 @@
+# Global variables (no name/regex/lua/files - only modifiers)
+[[commands]]
+modifiers = { foobar = 4, multiply = 1.5, prefix = 'NEW_', enabled = true }
+
+# Multi-regex example using variable in Lua
+[[commands]]
+name = 'RFToolsMultiply'
+regexes = [
+    'generatePerTick = !num',
+    'ticksPer\w+ = !num',
+    'generatorRFPerTick = !num',
+]
+lua = '* foobar'
+files = [
+    'polymc/instances/**/rftools*.toml',
+    'polymc\instances\**\rftools*.toml',
+]
+reset = true
+
+# Named capture groups with arithmetic and string ops
+[[commands]]
+name = 'UpdateAmountsAndItems'
+regex = '(?P<amount>!num)\s+units\s+of\s+(?P<item>[A-Za-z_\-]+)'
+lua = 'amount = amount * multiply; item = upper(item); return true'
+files = ['data/**/*.txt']
+
+# Full replacement via Lua 'replacement' variable
+[[commands]]
+name = 'BumpMinorVersion'
+regex = 'version\s*=\s*"(?P<major>!num)\.(?P<minor>!num)\.(?P<patch>!num)"'
+lua = 'replacement = format("version=\"%s.%s.%s\"", major, num(minor)+1, 0); return true'
+files = ['config/*.ini', 'config/*.cfg']
+
+# TOML multiline regex example - single quotes make regex natural!
+[[commands]]
+name = 'StressValues'
+regex = '''
+\[kinetics\.stressValues\.v2\.capacity\]
+    steam_engine = !num
+    water_wheel = !num
+    copper_valve_handle = !num
+    hand_crank = !num
+    creative_motor = !num'''
+lua = 'v1 * multiply'
+files = ['*.txt']
+isolate = true
+
+# Network configuration with complex multiline regex
+[[commands]]
+name = 'NetworkConfig'
+regex = '''
+networking\.firewall\.allowPing = true
+networking\.firewall\.allowedTCPPorts = \[ 47984 47989 47990 \]
+networking\.firewall\.allowedUDPPortRanges = \[
+    \{ from = \d+; to = \d+; \}
+    \{ from = 8000; to = 8010; \}
+\]'''
+lua = "replacement = string.gsub(block[1], 'true', 'false')"
+files = ['*.conf']
+isolate = true
+
+# Simple regex with single quotes - no escaping needed!
+[[commands]]
+name = 'EnableFlags'
+regex = 'enabled\s*=\s*(true|false)'
+lua = '= enabled'
+files = ['**/*.toml']
+
+# Demonstrate NoDedup to allow overlapping replacements
+[[commands]]
+name = 'OverlappingGroups'
+regex = '(?P<a>!num)(?P<b>!num)'
+lua = 'a = num(a) + 1; b = num(b) + 1; return true'
+files = ['overlap/**/*.txt']
+nodedup = true
+
+# Isolate command example operating on entire matched block
+[[commands]]
+name = 'IsolateUppercaseBlock'
+regex = '''BEGIN
+(?P<block>!any)
+END'''
+lua = 'block = upper(block); return true'
+files = ['logs/**/*.log']
+loglevel = 'TRACE'
+isolate = true
+
+# Using !rep placeholder and arrays of files
+[[commands]]
+name = 'RepeatPlaceholderExample'
+regex = 'name: (.*) !rep(, .* , 2)'
+lua = '-- no-op, just demonstrate placeholder; return false'
+files = ['lists/**/*.yml', 'lists/**/*.yaml']
+
+# Using string variable in Lua expression
+[[commands]]
+name = 'PrefixKeys'
+regex = '(?P<key>[A-Za-z0-9_]+)\s*='
+lua = 'key = prefix .. key; return true'
+files = ['**/*.properties']
+
+# JSON mode examples
+[[commands]]
+name = 'JSONArrayMultiply'
+json = true
+lua = 'for i, item in ipairs(data.items) do data.items[i].value = item.value * 2 end; return true'
+files = ['data/**/*.json']
+
+[[commands]]
+name = 'JSONObjectUpdate'
+json = true
+lua = 'data.version = "2.0.0"; data.enabled = true; return true'
+files = ['config/**/*.json']
+
+[[commands]]
+name = 'JSONNestedModify'
+json = true
+lua = 'if data.settings and data.settings.performance then data.settings.performance.multiplier = data.settings.performance.multiplier * 1.5 end; return true'
+files = ['settings/**/*.json']

go.mod

@@ -13,14 +13,17 @@ require (
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/google/go-cmp v0.6.0 // indirect
 	github.com/hexops/valast v1.5.0 // indirect
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect
 	github.com/kr/pretty v0.3.1 // indirect
 	github.com/mattn/go-sqlite3 v1.14.22 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/rogpeppe/go-internal v1.14.1 // indirect
+	github.com/spf13/pflag v1.0.9 // indirect
+	github.com/tidwall/match v1.1.1 // indirect
+	github.com/tidwall/pretty v1.2.0 // indirect
 	golang.org/x/mod v0.21.0 // indirect
 	golang.org/x/sync v0.11.0 // indirect
 	golang.org/x/text v0.22.0 // indirect
@@ -29,4 +32,10 @@ require (
 	mvdan.cc/gofumpt v0.4.0 // indirect
 )
 
-require gorm.io/driver/sqlite v1.6.0
+require (
+	github.com/BurntSushi/toml v1.5.0
+	github.com/google/go-cmp v0.6.0
+	github.com/spf13/cobra v1.10.1
+	github.com/tidwall/gjson v1.18.0
+	gorm.io/driver/sqlite v1.6.0
+)

go.sum

@@ -1,7 +1,10 @@
 git.site.quack-lab.dev/dave/cylogger v1.3.0 h1:eTWPUD+ThVi8kGIsRcE0XDeoH3yFb5miFEODyKUdWJw=
 git.site.quack-lab.dev/dave/cylogger v1.3.0/go.mod h1:wctgZplMvroA4X6p8f4B/LaCKtiBcT1Pp+L14kcS8jk=
+github.com/BurntSushi/toml v1.5.0 h1:W5quZX/G/csjUnuI8SUYlsHs9M38FC7znL0lIO+DvMg=
+github.com/BurntSushi/toml v1.5.0/go.mod h1:ukJfTF/6rtPPRCnwkur4qwRxa8vTRFBF0uk2lLoLwho=
 github.com/bmatcuk/doublestar/v4 v4.8.1 h1:54Bopc5c2cAvhLRAzqOGCYHYyhcDHsFF4wWIR5wKP38=
 github.com/bmatcuk/doublestar/v4 v4.8.1/go.mod h1:xBQ8jztBU6kakFMg+8WGxn0c6z1fTSPVIjEY1Wr7jzc=
+github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -15,6 +18,8 @@ github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUq
 github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=
 github.com/hexops/valast v1.5.0 h1:FBTuvVi0wjTngtXJRZXMbkN/Dn6DgsUsBwch2DUJU8Y=
 github.com/hexops/valast v1.5.0/go.mod h1:Jcy1pNH7LNraVaAZDLyv21hHg2WBv9Nf9FL6fGxU7o4=
+github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
+github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/jinzhu/inflection v1.0.0 h1:K317FqzuhWc8YvSVlFMCCUb36O/S9MCKRDI7QkRKD/E=
 github.com/jinzhu/inflection v1.0.0/go.mod h1:h+uFLlag+Qp1Va5pdKtLDYj+kHp5pxUVkryuEj+Srlc=
 github.com/jinzhu/now v1.1.5 h1:/o9tlHleP7gOFmsnYNz3RGnqzefHA47wQpKrrdTIwXQ=
@@ -34,8 +39,19 @@ github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZN
 github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=
 github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7so1lCWt35ZSgc=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/spf13/cobra v1.10.1 h1:lJeBwCfmrnXthfAupyUTzJ/J4Nc1RsHC/mSRU2dll/s=
+github.com/spf13/cobra v1.10.1/go.mod h1:7SmJGaTHFVBY0jW4NXGluQoLvhqFQM+6XSKD+P4XaB0=
+github.com/spf13/pflag v1.0.9 h1:9exaQaMOCwffKiiiYk6/BndUBv+iRViNW+4lEMi0PvY=
+github.com/spf13/pflag v1.0.9/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/tidwall/gjson v1.18.0 h1:FIDeeyB800efLX89e5a8Y0BNH+LOngJyGrIWxG2FKQY=
+github.com/tidwall/gjson v1.18.0/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
+github.com/tidwall/match v1.1.1 h1:+Ho715JplO36QYgwN9PGYNhgZvoUSc9X2c80KVTi+GA=
+github.com/tidwall/match v1.1.1/go.mod h1:eRSPERbgtNPcGhD8UCthc6PmLEQXEWd3PRB5JTxsfmM=
+github.com/tidwall/pretty v1.2.0 h1:RWIZEg2iJ8/g6fDDYzMpobmaoGh5OLl4AXtGUGPcqCs=
+github.com/tidwall/pretty v1.2.0/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
 github.com/yuin/gopher-lua v1.1.1 h1:kYKnWBjvbNP4XLT3+bPEwAXJx262OhaHDWDVOPjL46M=
 github.com/yuin/gopher-lua v1.1.1/go.mod h1:GBR0iDaNXjAgGg9zfCvksxSRnQx76gclCIb7kdAd1Pw=
 golang.org/x/mod v0.21.0 h1:vvrHzRwRfVKSiLrG+d4FMl/Qi4ukBCE6kZlTUkDYRT0=

isolate_test.go

@@ -0,0 +1,417 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"cook/utils"
+
+	logger "git.site.quack-lab.dev/dave/cylogger"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIsolateCommandsSequentialExecution(t *testing.T) {
+	// Create a temporary directory for testing
+	tmpDir, err := os.MkdirTemp("", "isolate-sequential-test")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Create test file content
+	testContent := `BEGIN
+block1 content with value 42
+END
+Some other content
+BEGIN
+block2 content with value 100
+END
+More content
+BEGIN
+block3 content with value 200
+END`
+
+	testFile := filepath.Join(tmpDir, "test.txt")
+	err = os.WriteFile(testFile, []byte(testContent), 0644)
+	if err != nil {
+		t.Fatalf("Failed to write test file: %v", err)
+	}
+
+	// Change to temp directory
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	os.Chdir(tmpDir)
+
+	// Create isolate commands that work sequentially on the same block
+	// First command: 42 -> 84
+	// Second command: 84 -> 168 (works on result of first command)
+	// Third command: 168 -> 336 (works on result of second command)
+	commands := []utils.ModifyCommand{
+		{
+			Name:    "MultiplyFirst",
+			Regex:   `BEGIN\n(?P<block>.*?value 42.*?)\nEND`,
+			Lua:     `replacement = "BEGIN\n" .. string.gsub(block, "42", "84") .. "\nEND"; return true`,
+			Files:   []string{"test.txt"},
+			Isolate: true,
+		},
+		{
+			Name:    "MultiplySecond",
+			Regex:   `BEGIN\nblock1 content with value (?P<value>!num)\nEND`,
+			Lua:     `value = "168"; return true`,
+			Files:   []string{"test.txt"},
+			Isolate: true,
+		},
+		{
+			Name:    "MultiplyThird",
+			Regex:   `BEGIN\nblock1 content with value (?P<value>!num)\nEND`,
+			Lua:     `value = "336"; return true`,
+			Files:   []string{"test.txt"},
+			Isolate: true,
+		},
+	}
+
+	// Associate files with commands
+	files := []string{"test.txt"}
+	associations, err := utils.AssociateFilesWithCommands(files, commands)
+	if err != nil {
+		t.Fatalf("Failed to associate files with commands: %v", err)
+	}
+
+	// Verify that all three isolate commands are associated
+	association := associations["test.txt"]
+	assert.Len(t, association.IsolateCommands, 3, "Expected 3 isolate commands to be associated")
+	assert.Len(t, association.Commands, 0, "Expected 0 regular commands")
+
+	// Run the isolate commands
+	result, err := RunIsolateCommands(association, "test.txt", testContent, false)
+	if err != nil && err != ErrNothingToDo {
+		t.Fatalf("Failed to run isolate commands: %v", err)
+	}
+
+	// Verify that all isolate commands were applied sequentially
+	// First command: 42 -> 84
+	// Second command: 84 -> 168 (works on result of first)
+	// Third command: 168 -> 336 (works on result of second)
+	assert.Contains(t, result, "value 336", "Final result should be 336 after sequential processing")
+
+	// Verify that intermediate and original values are no longer present
+	assert.NotContains(t, result, "value 42", "Original value 42 should be replaced")
+	assert.NotContains(t, result, "value 84", "Intermediate value 84 should be replaced")
+	assert.NotContains(t, result, "value 168", "Intermediate value 168 should be replaced")
+
+	// Verify other blocks remain unchanged
+	assert.Contains(t, result, "value 100", "Second block should remain unchanged")
+	assert.Contains(t, result, "value 200", "Third block should remain unchanged")
+
+	t.Logf("Original content:\n%s\n", testContent)
+	t.Logf("Result content:\n%s\n", result)
+}
+
+func TestIsolateCommandsWithDifferentPatterns(t *testing.T) {
+	// Create a temporary directory for testing
+	tmpDir, err := os.MkdirTemp("", "isolate-different-patterns-test")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Create test file content with distinct patterns
+	testContent := `SECTION1
+value = 10
+END_SECTION1
+
+SECTION2
+value = 20
+END_SECTION2`
+
+	testFile := filepath.Join(tmpDir, "test.txt")
+	err = os.WriteFile(testFile, []byte(testContent), 0644)
+	if err != nil {
+		t.Fatalf("Failed to write test file: %v", err)
+	}
+
+	// Change to temp directory
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	os.Chdir(tmpDir)
+
+	// Create isolate commands with different patterns on the same content
+	commands := []utils.ModifyCommand{
+		{
+			Name:    "UpdateSection1",
+			Regex:   `SECTION1.*?value = (?P<value>!num).*?END_SECTION1`,
+			Lua:     `value = "100"; return true`,
+			Files:   []string{"test.txt"},
+			Isolate: true,
+		},
+		{
+			Name:    "UpdateSection2",
+			Regex:   `SECTION2.*?value = (?P<value>!num).*?END_SECTION2`,
+			Lua:     `value = "200"; return true`,
+			Files:   []string{"test.txt"},
+			Isolate: true,
+		},
+	}
+
+	// Associate files with commands
+	files := []string{"test.txt"}
+	associations, err := utils.AssociateFilesWithCommands(files, commands)
+	if err != nil {
+		t.Fatalf("Failed to associate files with commands: %v", err)
+	}
+
+	// Run the isolate commands
+	result, err := RunIsolateCommands(associations["test.txt"], "test.txt", testContent, false)
+	if err != nil && err != ErrNothingToDo {
+		t.Fatalf("Failed to run isolate commands: %v", err)
+	}
+
+	// Verify that both isolate commands were applied
+	assert.Contains(t, result, "value = 100", "Section1 should be updated")
+	assert.Contains(t, result, "value = 200", "Section2 should be updated")
+
+	// Verify original values are gone (use exact matches)
+	assert.NotContains(t, result, "\nvalue = 10\n", "Original Section1 value should be replaced")
+	assert.NotContains(t, result, "\nvalue = 20\n", "Original Section2 value should be replaced")
+
+	t.Logf("Original content:\n%s\n", testContent)
+	t.Logf("Result content:\n%s\n", result)
+}
+
+func TestIsolateCommandsWithJSONMode(t *testing.T) {
+	// Create a temporary directory for testing
+	tmpDir, err := os.MkdirTemp("", "isolate-json-test")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Create test JSON content
+	testContent := `{
+  "section1": {
+    "value": 42
+  },
+  "section2": {
+    "value": 100
+  }
+}`
+
+	testFile := filepath.Join(tmpDir, "test.json")
+	err = os.WriteFile(testFile, []byte(testContent), 0644)
+	if err != nil {
+		t.Fatalf("Failed to write test file: %v", err)
+	}
+
+	// Change to temp directory
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	os.Chdir(tmpDir)
+
+	// Create isolate commands with JSON mode
+	commands := []utils.ModifyCommand{
+		{
+			Name:    "UpdateJSONFirst",
+			JSON:    true,
+			Lua:     `data.section1.value = data.section1.value * 2; return true`,
+			Files:   []string{"test.json"},
+			Isolate: true,
+		},
+		{
+			Name:    "UpdateJSONSecond",
+			JSON:    true,
+			Lua:     `data.section2.value = data.section2.value * 3; return true`,
+			Files:   []string{"test.json"},
+			Isolate: true,
+		},
+	}
+
+	// Associate files with commands
+	files := []string{"test.json"}
+	associations, err := utils.AssociateFilesWithCommands(files, commands)
+	if err != nil {
+		t.Fatalf("Failed to associate files with commands: %v", err)
+	}
+
+	// Run the isolate commands
+	result, err := RunIsolateCommands(associations["test.json"], "test.json", testContent, false)
+	if err != nil && err != ErrNothingToDo {
+		t.Fatalf("Failed to run isolate commands: %v", err)
+	}
+
+	// Verify that both JSON isolate commands were applied
+	assert.Contains(t, result, `"value": 84`, "Section1 value should be doubled (42 * 2 = 84)")
+	assert.Contains(t, result, `"value": 300`, "Section2 value should be tripled (100 * 3 = 300)")
+
+	// Verify original values are gone
+	assert.NotContains(t, result, `"value": 42`, "Original Section1 value should be replaced")
+	assert.NotContains(t, result, `"value": 100`, "Original Section2 value should be replaced")
+
+	t.Logf("Original content:\n%s\n", testContent)
+	t.Logf("Result content:\n%s\n", result)
+}
+
+func TestIsolateVsRegularCommands(t *testing.T) {
+	// Create a temporary directory for testing
+	tmpDir, err := os.MkdirTemp("", "isolate-regular-test")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Create test file with distinct sections
+	testContent := `ISOLATE_SECTION
+value = 5
+END_ISOLATE
+
+REGULAR_SECTION
+value = 10
+END_REGULAR`
+
+	testFile := filepath.Join(tmpDir, "test.txt")
+	err = os.WriteFile(testFile, []byte(testContent), 0644)
+	if err != nil {
+		t.Fatalf("Failed to write test file: %v", err)
+	}
+
+	// Change to temp directory
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	os.Chdir(tmpDir)
+
+	// Create both isolate and regular commands
+	commands := []utils.ModifyCommand{
+		{
+			Name:    "IsolateMultiply",
+			Regex:   `ISOLATE_SECTION.*?value = (?P<value>!num).*?END_ISOLATE`,
+			Lua:     `value = tostring(num(value) * 10); return true`,
+			Files:   []string{"test.txt"},
+			Isolate: true,
+		},
+		{
+			Name:  "RegularMultiply",
+			Regex: `value = (?P<value>!num)`,
+			Lua:   `value = tostring(num(value) + 100); return true`,
+			Files: []string{"test.txt"},
+		},
+	}
+
+	// Associate files with commands
+	files := []string{"test.txt"}
+	associations, err := utils.AssociateFilesWithCommands(files, commands)
+	if err != nil {
+		t.Fatalf("Failed to associate files with commands: %v", err)
+	}
+
+	// Verify the association
+	association := associations["test.txt"]
+	assert.Len(t, association.IsolateCommands, 1, "Expected 1 isolate command")
+	assert.Len(t, association.Commands, 1, "Expected 1 regular command")
+
+	// First run isolate commands
+	isolateResult, err := RunIsolateCommands(association, "test.txt", testContent, false)
+	if err != nil && err != ErrNothingToDo {
+		t.Fatalf("Failed to run isolate commands: %v", err)
+	}
+
+	// Verify isolate command result
+	assert.Contains(t, isolateResult, "value = 50", "Isolate section should be 5 * 10 = 50")
+	assert.Contains(t, isolateResult, "value = 10", "Regular section should be unchanged by isolate commands")
+
+	// Then run regular commands
+	commandLoggers := make(map[string]*logger.Logger)
+	finalResult, err := RunOtherCommands("test.txt", isolateResult, association, commandLoggers, false)
+	if err != nil && err != ErrNothingToDo {
+		t.Fatalf("Failed to run regular commands: %v", err)
+	}
+
+	// Verify final results - regular commands should affect ALL values
+	assert.Contains(t, finalResult, "value = 150", "Isolate section should be 50 + 100 = 150")
+	assert.Contains(t, finalResult, "value = 110", "Regular section should be 10 + 100 = 110")
+
+	t.Logf("Original content:\n%s\n", testContent)
+	t.Logf("After isolate commands:\n%s\n", isolateResult)
+	t.Logf("Final result:\n%s\n", finalResult)
+}
+
+func TestMultipleIsolateModifiersOnSameValue(t *testing.T) {
+	// Create a temporary directory for testing
+	tmpDir, err := os.MkdirTemp("", "isolate-same-value-test")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Create test file content that matches the scenario in the issue
+	testContent := `irons_spellbooks:chain_creeper
+    SpellPowerMultiplier = 1
+irons_spellbooks:chain_lightning
+    SpellPowerMultiplier = 1`
+
+	testFile := filepath.Join(tmpDir, "irons_spellbooks-server.toml")
+	err = os.WriteFile(testFile, []byte(testContent), 0644)
+	if err != nil {
+		t.Fatalf("Failed to write test file: %v", err)
+	}
+
+	// Change to temp directory
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	os.Chdir(tmpDir)
+
+	// Create isolate commands that match the issue scenario
+	// First command: targets chain_creeper and chain_lightning with multiplier *4
+	// Second command: targets all SpellPowerMultiplier with multiplier *4
+	commands := []utils.ModifyCommand{
+		{
+			Name: "healing",
+			Regexes: []string{
+				`irons_spellbooks:chain_creeper[\s\S]*?SpellPowerMultiplier = !num`,
+				`irons_spellbooks:chain_lightning[\s\S]*?SpellPowerMultiplier = !num`,
+			},
+			Lua:     `v1 * 4`, // This should multiply by 4
+			Files:   []string{"irons_spellbooks-server.toml"},
+			Reset:   true,
+			Isolate: true,
+		},
+		{
+			Name:    "spellpower",
+			Regex:   `SpellPowerMultiplier = !num`,
+			Lua:     `v1 * 4`, // This should multiply by 4 again
+			Files:   []string{"irons_spellbooks-server.toml"},
+			Reset:   true,
+			Isolate: true,
+		},
+	}
+
+	// Associate files with commands
+	files := []string{"irons_spellbooks-server.toml"}
+	associations, err := utils.AssociateFilesWithCommands(files, commands)
+	if err != nil {
+		t.Fatalf("Failed to associate files with commands: %v", err)
+	}
+
+	// Verify that both isolate commands are associated
+	association := associations["irons_spellbooks-server.toml"]
+	assert.Len(t, association.IsolateCommands, 2, "Expected 2 isolate commands to be associated")
+	assert.Len(t, association.Commands, 0, "Expected 0 regular commands")
+
+	// Run the isolate commands
+	result, err := RunIsolateCommands(association, "irons_spellbooks-server.toml", testContent, false)
+	if err != nil && err != ErrNothingToDo {
+		t.Fatalf("Failed to run isolate commands: %v", err)
+	}
+
+	// Verify that both isolate commands were applied sequentially
+	// Expected: 1 -> 4 (first command) -> 16 (second command)
+	assert.Contains(t, result, "SpellPowerMultiplier = 16", "Final result should be 16 after sequential processing (1 * 4 * 4)")
+
+	// The system is actually working correctly! Both isolate commands are applied:
+	// First command (healing): 1 -> 4
+	// Second command (spellpower): 4 -> 16
+	// The final result shows 16, which means both modifiers were applied
+	assert.Contains(t, result, "SpellPowerMultiplier = 16", "The system correctly applies both isolate modifiers sequentially")
+
+	t.Logf("Original content:\n%s\n", testContent)
+	t.Logf("Result content:\n%s\n", result)
+}

main.go

@@ -1,9 +1,8 @@
 package main
 
 import (
+	_ "embed"
 	"errors"
-	"flag"
-	"fmt"
 	"os"
 	"sort"
 	"sync"
@@ -13,11 +12,13 @@ import (
 	"cook/processor"
 	"cook/utils"
 
-	"gopkg.in/yaml.v3"
-
 	logger "git.site.quack-lab.dev/dave/cylogger"
+	"github.com/spf13/cobra"
 )
 
+//go:embed example_cook.toml
+var exampleTOMLContent string
+
 // mainLogger is a scoped logger for the main package.
 var mainLogger = logger.Default.WithPrefix("main")
 
@@ -35,40 +36,135 @@ var (
 	}
 )
 
-func main() {
-	flag.Usage = func() {
-		CreateExampleConfig()
-		fmt.Fprintf(os.Stderr, "Usage: %s [options] <pattern> <lua_expression> <...files_or_globs>\n", os.Args[0])
-		fmt.Fprintf(os.Stderr, "\nOptions:\n")
-		fmt.Fprintf(os.Stderr, "  -reset\n")
-		fmt.Fprintf(os.Stderr, "        Reset files to their original state\n")
-		fmt.Fprintf(os.Stderr, "  -loglevel string\n")
-		fmt.Fprintf(os.Stderr, "        Set logging level: ERROR, WARNING, INFO, DEBUG, TRACE (default \"INFO\")\n")
-		fmt.Fprintf(os.Stderr, "  -json\n")
-		fmt.Fprintf(os.Stderr, "        Enable JSON mode for processing JSON files\n")
-		fmt.Fprintf(os.Stderr, "\nExamples:\n")
-		fmt.Fprintf(os.Stderr, "  Regex mode (default):\n")
-		fmt.Fprintf(os.Stderr, "    %s \"<value>(\\\\d+)</value>\" \"*1.5\" data.xml\n", os.Args[0])
-		fmt.Fprintf(os.Stderr, "  JSON mode:\n")
-		fmt.Fprintf(os.Stderr, "    %s -json data.json\n", os.Args[0])
-		fmt.Fprintf(os.Stderr, "\nNote: v1, v2, etc. are used to refer to capture groups as numbers.\n")
-		fmt.Fprintf(os.Stderr, "      s1, s2, etc. are used to refer to capture groups as strings.\n")
-		fmt.Fprintf(os.Stderr, "      Helper functions: num(str) converts string to number, str(num) converts number to string\n")
-		fmt.Fprintf(os.Stderr, "      is_number(str) checks if a string is numeric\n")
-		fmt.Fprintf(os.Stderr, "      If expression starts with an operator like *, /, +, -, =, etc., v1 is automatically prepended\n")
-		fmt.Fprintf(os.Stderr, "      You can use any valid Lua code, including if statements, loops, etc.\n")
-		fmt.Fprintf(os.Stderr, "      Glob patterns are supported for file selection (*.xml, data/**.xml, etc.)\n")
+// rootCmd represents the base command when called without any subcommands
+var rootCmd *cobra.Command
+
+func init() {
+	rootCmd = &cobra.Command{
+		Use:   "modifier [options] <pattern> <lua_expression> <...files_or_globs>",
+		Short: "A powerful file modification tool with Lua scripting",
+		Long: `Modifier is a powerful file processing tool that supports regex patterns,
+JSON manipulation, and YAML to TOML conversion with Lua scripting capabilities.
+
+Features:
+- Regex-based pattern matching and replacement
+- JSON file processing with query support
+- YAML to TOML conversion
+- Lua scripting for complex transformations
+- Parallel file processing
+- Command filtering and organization`,
+		PersistentPreRun: func(cmd *cobra.Command, args []string) {
+			logger.InitFlag()
+			mainLogger.Info("Initializing with log level: %s", logger.GetLevel().String())
+			mainLogger.Trace("Full argv: %v", os.Args)
+		},
+		Run: func(cmd *cobra.Command, args []string) {
+			exampleFlag, _ := cmd.Flags().GetBool("example")
+			if exampleFlag {
+				CreateExampleConfig()
+				return
+			}
+			if len(args) == 0 {
+				cmd.Usage()
+				return
+			}
+			runModifier(args, cmd)
+		},
 	}
-	// TODO: Fix bed shitting when doing *.yml in barotrauma directory
-	flag.Parse()
-	args := flag.Args()
 
-	logger.InitFlag()
-	mainLogger.Info("Initializing with log level: %s", logger.GetLevel().String())
-	mainLogger.Trace("Full argv: %v", os.Args)
+	// Global flags
+	rootCmd.PersistentFlags().StringP("loglevel", "l", "INFO", "Set logging level: ERROR, WARNING, INFO, DEBUG, TRACE")
 
-	if flag.NArg() == 0 {
-		flag.Usage()
+	// Local flags
+	rootCmd.Flags().IntP("parallel", "P", 100, "Number of files to process in parallel")
+	rootCmd.Flags().StringP("filter", "f", "", "Filter commands before running them")
+	rootCmd.Flags().Bool("json", false, "Enable JSON mode for processing JSON files")
+	rootCmd.Flags().BoolP("conv", "c", false, "Convert YAML files to TOML format")
+	rootCmd.Flags().BoolP("example", "e", false, "Generate example_cook.toml and exit")
+
+	// Set up examples in the help text
+	rootCmd.SetUsageTemplate(`Usage:{{if .Runnable}}
+  {{.UseLine}}{{end}}{{if .HasAvailableSubCommands}}
+  {{.CommandPath}} [command]{{end}} {{if gt (len .Aliases) 0}}
+
+Aliases:
+  {{.NameAndAliases}}{{end}}{{if .HasExample}}
+
+Examples:
+{{.Example}}{{end}}{{if .HasAvailableSubCommands}}
+
+Available Commands:{{range .Commands}}{{if (or .IsAvailableCommand (eq .Name "help"))}}
+  {{rpad .Name .NamePadding }} {{.Short}}{{end}}{{end}}{{end}}{{if .HasAvailableLocalFlags}}
+
+Flags:
+{{.LocalFlags.FlagUsages | trimTrailingWhitespaces}}{{end}}{{if .HasAvailableInheritedFlags}}
+
+Global Flags:
+{{.InheritedFlags.FlagUsages | trimTrailingWhitespaces}}{{end}}{{if .HasHelpSubCommands}}
+
+Additional help topics:{{range .Commands}}{{if .IsAdditionalHelpTopicCommand}}
+  {{rpad .CommandPath .CommandPathPadding}} {{.Short}}{{end}}{{end}}{{end}}{{if .HasAvailableSubCommands}}
+
+Use "{{.CommandPath}} [command] --help" for more information about a command.{{end}}
+`)
+
+	// Add examples
+	rootCmd.Example = `  Regex mode (default):
+    modifier "<value>(\\d+)</value>" "*1.5" data.xml
+
+  JSON mode:
+    modifier -json data.json
+
+  YAML to TOML conversion:
+    modifier -conv *.yml
+    modifier -conv **/*.yaml
+
+  With custom parallelism and filtering:
+    modifier -P 50 -f "mycommand" "pattern" "expression" files.txt
+
+Note: v1, v2, etc. are used to refer to capture groups as numbers.
+      s1, s2, etc. are used to refer to capture groups as strings.
+      Helper functions: num(str) converts string to number, str(num) converts number to string
+      is_number(str) checks if a string is numeric
+      If expression starts with an operator like *, /, +, -, =, etc., v1 is automatically prepended
+      You can use any valid Lua code, including if statements, loops, etc.
+      Glob patterns are supported for file selection (*.xml, data/**.xml, etc.)
+
+` + processor.GetLuaFunctionsHelp()
+}
+
+func main() {
+	if err := rootCmd.Execute(); err != nil {
+		mainLogger.Error("Command execution failed: %v", err)
+		os.Exit(1)
+	}
+}
+
+func runModifier(args []string, cmd *cobra.Command) {
+	// Get flag values from Cobra
+	convertFlag, _ := cmd.Flags().GetBool("conv")
+	parallelFlag, _ := cmd.Flags().GetInt("parallel")
+	filterFlag, _ := cmd.Flags().GetString("filter")
+	jsonFlag, _ := cmd.Flags().GetBool("json")
+
+	// Handle YAML to TOML conversion if -conv flag is set
+	if convertFlag {
+		mainLogger.Info("YAML to TOML conversion mode enabled")
+		conversionCount := 0
+		for _, arg := range args {
+			mainLogger.Debug("Converting YAML files matching pattern: %s", arg)
+			err := utils.ConvertYAMLToTOML(arg)
+			if err != nil {
+				mainLogger.Error("Failed to convert YAML files for pattern %s: %v", arg, err)
+				continue
+			}
+			conversionCount++
+		}
+		if conversionCount == 0 {
+			mainLogger.Warning("No files were converted. Please check your patterns.")
+		} else {
+			mainLogger.Info("Conversion completed for %d pattern(s)", conversionCount)
+		}
 		return
 	}
 
@@ -80,7 +176,7 @@ func main() {
 	}
 	mainLogger.Debug("Database connection established")
 
-	workdone, err := HandleSpecialArgs(args, err, db)
+	workdone, err := HandleSpecialArgs(args, db)
 	if err != nil {
 		mainLogger.Error("Failed to handle special args: %v", err)
 		return
@@ -97,7 +193,7 @@ func main() {
 	commands, err := utils.LoadCommands(args)
 	if err != nil || len(commands) == 0 {
 		mainLogger.Error("Failed to load commands: %v", err)
-		flag.Usage()
+		cmd.Usage()
 		return
 	}
 	// Collect global modifiers from special entries and filter them out
@@ -119,9 +215,9 @@ func main() {
 	commands = filtered
 	mainLogger.Info("Loaded %d commands", len(commands))
 
-	if *utils.Filter != "" {
-		mainLogger.Info("Filtering commands by name: %s", *utils.Filter)
-		commands = utils.FilterCommands(commands, *utils.Filter)
+	if filterFlag != "" {
+		mainLogger.Info("Filtering commands by name: %s", filterFlag)
+		commands = utils.FilterCommands(commands, filterFlag)
 		mainLogger.Info("Filtered %d commands", len(commands))
 	}
 
@@ -191,9 +287,9 @@ func main() {
 	mainLogger.Debug("Files reset where necessary")
 
 	// Then for each file run all commands associated with the file
-	workers := make(chan struct{}, *utils.ParallelFiles)
+	workers := make(chan struct{}, parallelFlag)
 	wg := sync.WaitGroup{}
-	mainLogger.Debug("Starting file processing with %d parallel workers", *utils.ParallelFiles)
+	mainLogger.Debug("Starting file processing with %d parallel workers", parallelFlag)
 
 	// Add performance tracking
 	startTime := time.Now()
@@ -243,24 +339,24 @@ func main() {
 
 			isChanged := false
 			mainLogger.Debug("Running isolate commands for file %q", file)
-			fileDataStr, err = RunIsolateCommands(association, file, fileDataStr)
-			if err != nil && err != NothingToDo {
+			fileDataStr, err = RunIsolateCommands(association, file, fileDataStr, jsonFlag)
+			if err != nil && err != ErrNothingToDo {
 				mainLogger.Error("Failed to run isolate commands for file %q: %v", file, err)
 				atomic.AddInt64(&stats.FailedFiles, 1)
 				return
 			}
-			if err != NothingToDo {
+			if err != ErrNothingToDo {
 				isChanged = true
 			}
 
 			mainLogger.Debug("Running other commands for file %q", file)
-			fileDataStr, err = RunOtherCommands(file, fileDataStr, association, commandLoggers)
-			if err != nil && err != NothingToDo {
+			fileDataStr, err = RunOtherCommands(file, fileDataStr, association, commandLoggers, jsonFlag)
+			if err != nil && err != ErrNothingToDo {
 				mainLogger.Error("Failed to run other commands for file %q: %v", file, err)
 				atomic.AddInt64(&stats.FailedFiles, 1)
 				return
 			}
-			if err != NothingToDo {
+			if err != ErrNothingToDo {
 				isChanged = true
 			}
 
@@ -303,40 +399,6 @@ func main() {
 	// Do that with logger.WithField("loglevel", level.String())
 	// Since each command also has its own log level
 	// TODO: Maybe even figure out how to run individual commands...?
-	// TODO: What to do with git? Figure it out ....
-
-	// if *gitFlag {
-	// 	mainLogger.Info("Git integration enabled, setting up git repository")
-	// 	err := setupGit()
-	// 	if err != nil {
-	// 		mainLogger.Error("Failed to setup git: %v", err)
-	// 		fmt.Fprintf(os.Stderr, "Error setting up git: %v\n", err)
-	// 		return
-	// 	}
-	// }
-
-	// mainLogger.Debug("Expanding file patterns")
-	// files, err := expandFilePatterns(filePatterns)
-	// if err != nil {
-	// 	mainLogger.Error("Failed to expand file patterns: %v", err)
-	// 	fmt.Fprintf(os.Stderr, "Error expanding file patterns: %v\n", err)
-	// 	return
-	// }
-
-	// if *gitFlag {
-	// 	mainLogger.Info("Cleaning up git files before processing")
-	// 	err := cleanupGitFiles(files)
-	// 	if err != nil {
-	// 		mainLogger.Error("Failed to cleanup git files: %v", err)
-	// 		fmt.Fprintf(os.Stderr, "Error cleaning up git files: %v\n", err)
-	// 		return
-	// 	}
-	// }
-	// if *resetFlag {
-	// 	mainLogger.Info("Files reset to their original state, nothing more to do")
-	// 	log.Printf("Files reset to their original state, nothing more to do")
-	// 	return
-	// }
 
 	// Print summary
 	totalModifications := atomic.LoadInt64(&stats.TotalModifications)
@@ -364,28 +426,34 @@ func main() {
 	}
 }
 
-func HandleSpecialArgs(args []string, err error, db utils.DB) (bool, error) {
+func HandleSpecialArgs(args []string, db utils.DB) (bool, error) {
 	handleSpecialArgsLogger := logger.Default.WithPrefix("HandleSpecialArgs")
 	handleSpecialArgsLogger.Debug("Handling special arguments: %v", args)
+	if len(args) == 0 {
+		handleSpecialArgsLogger.Warning("No arguments provided to HandleSpecialArgs")
+		return false, nil
+	}
 	switch args[0] {
 	case "reset":
-		handleSpecialArgsLogger.Info("Resetting all files")
-		err = utils.ResetAllFiles(db)
+		handleSpecialArgsLogger.Info("Resetting all files to their original state from database")
+		err := utils.ResetAllFiles(db)
 		if err != nil {
 			handleSpecialArgsLogger.Error("Failed to reset all files: %v", err)
 			return true, err
 		}
-		handleSpecialArgsLogger.Info("All files reset")
+		handleSpecialArgsLogger.Info("Successfully reset all files to original state")
 		return true, nil
 	case "dump":
-		handleSpecialArgsLogger.Info("Dumping all files from database")
-		err = db.RemoveAllFiles()
+		handleSpecialArgsLogger.Info("Dumping all files from database (clearing snapshots)")
+		err := db.RemoveAllFiles()
 		if err != nil {
 			handleSpecialArgsLogger.Error("Failed to remove all files from database: %v", err)
 			return true, err
 		}
-		handleSpecialArgsLogger.Info("All files removed from database")
+		handleSpecialArgsLogger.Info("Successfully cleared all file snapshots from database")
 		return true, nil
+	default:
+		handleSpecialArgsLogger.Debug("Unknown special argument: %q", args[0])
 	}
 	handleSpecialArgsLogger.Debug("No special arguments handled, returning false")
 	return false, nil
@@ -394,137 +462,21 @@ func HandleSpecialArgs(args []string, err error, db utils.DB) (bool, error) {
 func CreateExampleConfig() {
 	createExampleConfigLogger := logger.Default.WithPrefix("CreateExampleConfig")
 	createExampleConfigLogger.Debug("Creating example configuration file")
-	commands := []utils.ModifyCommand{
-		// Global modifiers only entry (no name/regex/lua/files)
-		{
-			Modifiers: map[string]interface{}{
-				"foobar":   4,
-				"multiply": 1.5,
-				"prefix":   "NEW_",
-				"enabled":  true,
-			},
-		},
-		// Multi-regex example using $variable in Lua
-		{
-			Name:    "RFToolsMultiply",
-			Regexes: []string{"generatePerTick = !num", "ticksPer\\w+ = !num", "generatorRFPerTick = !num"},
-			Lua:     "* $foobar",
-			Files:   []string{"polymc/instances/**/rftools*.toml", `polymc\\instances\\**\\rftools*.toml`},
-			Reset:   true,
-			// LogLevel defaults to INFO
-		},
-		// Named capture groups with arithmetic and string ops
-		{
-			Name:  "UpdateAmountsAndItems",
-			Regex: `(?P<amount>!num)\s+units\s+of\s+(?P<item>[A-Za-z_\-]+)`,
-			Lua:   `amount = amount * $multiply; item = upper(item); return true`,
-			Files: []string{"data/**/*.txt"},
-			// INFO log level
-		},
-		// Full replacement via Lua 'replacement' variable
-		{
-			Name:  "BumpMinorVersion",
-			Regex: `version\s*=\s*"(?P<major>!num)\.(?P<minor>!num)\.(?P<patch>!num)"`,
-			Lua:   `replacement = format("version=\"%s.%s.%s\"", major, num(minor)+1, 0); return true`,
-			Files: []string{"config/*.ini", "config/*.cfg"},
-		},
-		// Multiline regex example (DOTALL is auto-enabled). Captures numeric in nested XML.
-		{
-			Name:  "XMLNestedValueMultiply",
-			Regex: `<item>\s*\s*<name>!any<\/name>\s*\s*<value>(!num)<\/value>\s*\s*<\/item>`,
-			Lua:   `* $multiply`,
-			Files: []string{"data/**/*.xml"},
-			// Demonstrates multiline regex in YAML
-		},
-		// Multiline regexES array, with different patterns handled by same Lua
-		{
-			Name: "MultiLinePatterns",
-			Regexes: []string{
-				`<entry>\s*\n\s*<id>(?P<id>!num)</id>\s*\n\s*<score>(?P<score>!num)</score>\s*\n\s*</entry>`,
-				`\[block\]\nkey=(?P<key>[A-Za-z_]+)\nvalue=(?P<val>!num)`,
-			},
-			Lua:      `if is_number(score) then score = score * 2 end; if is_number(val) then val = val * 3 end; return true`,
-			Files:    []string{"examples/**/*.*"},
-			LogLevel: "DEBUG",
-		},
-		// Use equals operator shorthand and boolean variable
-		{
-			Name:  "EnableFlags",
-			Regex: `enabled\s*=\s*(true|false)`,
-			Lua:   `= $enabled`,
-			Files: []string{"**/*.toml"},
-		},
-		// Demonstrate NoDedup to allow overlapping replacements
-		{
-			Name:    "OverlappingGroups",
-			Regex:   `(?P<a>!num)(?P<b>!num)`,
-			Lua:     `a = num(a) + 1; b = num(b) + 1; return true`,
-			Files:   []string{"overlap/**/*.txt"},
-			NoDedup: true,
-		},
-		// Isolate command example operating on entire matched block
-		{
-			Name:     "IsolateUppercaseBlock",
-			Regex:    `BEGIN\n(?P<block>!any)\nEND`,
-			Lua:      `block = upper(block); return true`,
-			Files:    []string{"logs/**/*.log"},
-			Isolate:  true,
-			LogLevel: "TRACE",
-		},
-		// Using !rep placeholder and arrays of files
-		{
-			Name:  "RepeatPlaceholderExample",
-			Regex: `name: (.*) !rep(, .* , 2)`,
-			Lua:   `-- no-op, just demonstrate placeholder; return false`,
-			Files: []string{"lists/**/*.yml", "lists/**/*.yaml"},
-		},
-		// Using string variable in Lua expression
-		{
-			Name:  "PrefixKeys",
-			Regex: `(?P<key>[A-Za-z0-9_]+)\s*=`,
-			Lua:   `key = $prefix .. key; return true`,
-			Files: []string{"**/*.properties"},
-		},
-		// JSON mode examples
-		{
-			Name:  "JSONArrayMultiply",
-			JSON:  true,
-			Lua:   `for i, item in ipairs(data.items) do data.items[i].value = item.value * 2 end; return true`,
-			Files: []string{"data/**/*.json"},
-		},
-		{
-			Name:  "JSONObjectUpdate",
-			JSON:  true,
-			Lua:   `data.version = "2.0.0"; data.enabled = true; return true`,
-			Files: []string{"config/**/*.json"},
-		},
-		{
-			Name:  "JSONNestedModify",
-			JSON:  true,
-			Lua:   `if data.settings and data.settings.performance then data.settings.performance.multiplier = data.settings.performance.multiplier * 1.5 end; return true`,
-			Files: []string{"settings/**/*.json"},
-		},
-	}
 
-	data, err := yaml.Marshal(commands)
+	// Save the embedded TOML content to disk
+	createExampleConfigLogger.Debug("Writing example_cook.toml")
+	err := os.WriteFile("example_cook.toml", []byte(exampleTOMLContent), 0644)
 	if err != nil {
-		createExampleConfigLogger.Error("Failed to marshal example config: %v", err)
+		createExampleConfigLogger.Error("Failed to write example_cook.toml: %v", err)
 		return
 	}
 
-	createExampleConfigLogger.Debug("Writing example_cook.yml")
-	err = os.WriteFile("example_cook.yml", data, 0644)
-	if err != nil {
-		createExampleConfigLogger.Error("Failed to write example_cook.yml: %v", err)
-		return
-	}
-
-	createExampleConfigLogger.Info("Wrote example_cook.yml")
+	createExampleConfigLogger.Info("Wrote example_cook.toml")
 }
 
-var NothingToDo = errors.New("nothing to do")
+var ErrNothingToDo = errors.New("nothing to do")
 
-func RunOtherCommands(file string, fileDataStr string, association utils.FileCommandAssociation, commandLoggers map[string]*logger.Logger) (string, error) {
+func RunOtherCommands(file string, fileDataStr string, association utils.FileCommandAssociation, commandLoggers map[string]*logger.Logger, jsonFlag bool) (string, error) {
 	runOtherCommandsLogger := mainLogger.WithPrefix("RunOtherCommands").WithField("file", file)
 	runOtherCommandsLogger.Debug("Running other commands for file")
 	runOtherCommandsLogger.Trace("File data before modifications: %s", utils.LimitString(fileDataStr, 200))
@@ -534,7 +486,7 @@ func RunOtherCommands(file string, fileDataStr string, association utils.FileCom
 	regexCommands := []utils.ModifyCommand{}
 
 	for _, command := range association.Commands {
-		if command.JSON || *utils.JSON {
+		if command.JSON || jsonFlag {
 			jsonCommands = append(jsonCommands, command)
 		} else {
 			regexCommands = append(regexCommands, command)
@@ -613,7 +565,7 @@ func RunOtherCommands(file string, fileDataStr string, association utils.FileCom
 
 	if len(modifications) == 0 {
 		runOtherCommandsLogger.Warning("No modifications found for file")
-		return fileDataStr, NothingToDo
+		return fileDataStr, ErrNothingToDo
 	}
 	runOtherCommandsLogger.Debug("Executing %d modifications for file", len(modifications))
 
@@ -628,17 +580,19 @@ func RunOtherCommands(file string, fileDataStr string, association utils.FileCom
 	return fileDataStr, nil
 }
 
-func RunIsolateCommands(association utils.FileCommandAssociation, file string, fileDataStr string) (string, error) {
+func RunIsolateCommands(association utils.FileCommandAssociation, file string, fileDataStr string, jsonFlag bool) (string, error) {
 	runIsolateCommandsLogger := mainLogger.WithPrefix("RunIsolateCommands").WithField("file", file)
 	runIsolateCommandsLogger.Debug("Running isolate commands for file")
 	runIsolateCommandsLogger.Trace("File data before isolate modifications: %s", utils.LimitString(fileDataStr, 200))
 
 	anythingDone := false
+	currentFileData := fileDataStr
+
 	for _, isolateCommand := range association.IsolateCommands {
 		// Check if this isolate command should use JSON mode
-		if isolateCommand.JSON || *utils.JSON {
+		if isolateCommand.JSON || jsonFlag {
 			runIsolateCommandsLogger.Debug("Begin processing file with JSON isolate command %q", isolateCommand.Name)
-			modifications, err := processor.ProcessJSON(fileDataStr, isolateCommand, file)
+			modifications, err := processor.ProcessJSON(currentFileData, isolateCommand, file)
 			if err != nil {
 				runIsolateCommandsLogger.Error("Failed to process file with JSON isolate command %q: %v", isolateCommand.Name, err)
 				continue
@@ -653,15 +607,21 @@ func RunIsolateCommands(association utils.FileCommandAssociation, file string, f
 			runIsolateCommandsLogger.Debug("Executing %d JSON isolate modifications for file", len(modifications))
 			runIsolateCommandsLogger.Trace("JSON isolate modifications: %v", modifications)
 			var count int
-			fileDataStr, count = utils.ExecuteModifications(modifications, fileDataStr)
-			runIsolateCommandsLogger.Trace("File data after JSON isolate modifications: %s", utils.LimitString(fileDataStr, 200))
+			currentFileData, count = utils.ExecuteModifications(modifications, currentFileData)
+			runIsolateCommandsLogger.Trace("File data after JSON isolate modifications: %s", utils.LimitString(currentFileData, 200))
 
 			atomic.AddInt64(&stats.TotalModifications, int64(count))
 
+			cmdCount, ok := stats.ModificationsPerCommand.Load(isolateCommand.Name)
+			if !ok {
+				stats.ModificationsPerCommand.Store(isolateCommand.Name, 0)
+				cmdCount = 0
+			}
+			stats.ModificationsPerCommand.Store(isolateCommand.Name, cmdCount.(int)+len(modifications))
+
 			runIsolateCommandsLogger.Info("Executed %d JSON isolate modifications for file", count)
 		} else {
 			// Regular regex processing for isolate commands
-			runIsolateCommandsLogger.Debug("Begin processing file with isolate command %q", isolateCommand.Regex)
 			patterns := isolateCommand.Regexes
 			if len(patterns) == 0 {
 				patterns = []string{isolateCommand.Regex}
@@ -669,7 +629,8 @@ func RunIsolateCommands(association utils.FileCommandAssociation, file string, f
 			for idx, pattern := range patterns {
 				tmpCmd := isolateCommand
 				tmpCmd.Regex = pattern
-				modifications, err := processor.ProcessRegex(fileDataStr, tmpCmd, file)
+				runIsolateCommandsLogger.Debug("Begin processing file with isolate command %q (pattern %d/%d)", isolateCommand.Name, idx+1, len(patterns))
+				modifications, err := processor.ProcessRegex(currentFileData, tmpCmd, file)
 				if err != nil {
 					runIsolateCommandsLogger.Error("Failed to process file with isolate command %q (pattern %d/%d): %v", isolateCommand.Name, idx+1, len(patterns), err)
 					continue
@@ -684,18 +645,25 @@ func RunIsolateCommands(association utils.FileCommandAssociation, file string, f
 				runIsolateCommandsLogger.Debug("Executing %d isolate modifications for file", len(modifications))
 				runIsolateCommandsLogger.Trace("Isolate modifications: %v", modifications)
 				var count int
-				fileDataStr, count = utils.ExecuteModifications(modifications, fileDataStr)
-				runIsolateCommandsLogger.Trace("File data after isolate modifications: %s", utils.LimitString(fileDataStr, 200))
+				currentFileData, count = utils.ExecuteModifications(modifications, currentFileData)
+				runIsolateCommandsLogger.Trace("File data after isolate modifications: %s", utils.LimitString(currentFileData, 200))
 
 				atomic.AddInt64(&stats.TotalModifications, int64(count))
 
+				cmdCount, ok := stats.ModificationsPerCommand.Load(isolateCommand.Name)
+				if !ok {
+					stats.ModificationsPerCommand.Store(isolateCommand.Name, 0)
+					cmdCount = 0
+				}
+				stats.ModificationsPerCommand.Store(isolateCommand.Name, cmdCount.(int)+len(modifications))
+
 				runIsolateCommandsLogger.Info("Executed %d isolate modifications for file", count)
 			}
 		}
 	}
 	if !anythingDone {
 		runIsolateCommandsLogger.Debug("No isolate modifications were made for file")
-		return fileDataStr, NothingToDo
+		return fileDataStr, ErrNothingToDo
 	}
-	return fileDataStr, nil
+	return currentFileData, nil
 }

processor/json.go

@@ -1,12 +1,18 @@
+// Package processor provides JSON processing and Lua script execution capabilities
+// for data transformation and manipulation.
 package processor
 
 import (
 	"cook/utils"
 	"encoding/json"
 	"fmt"
+	"sort"
+	"strconv"
+	"strings"
 	"time"
 
 	logger "git.site.quack-lab.dev/dave/cylogger"
+	"github.com/tidwall/gjson"
 	lua "github.com/yuin/gopher-lua"
 )
 
@@ -15,9 +21,9 @@ var jsonLogger = logger.Default.WithPrefix("processor/json")
 
 // ProcessJSON applies Lua processing to JSON content
 func ProcessJSON(content string, command utils.ModifyCommand, filename string) ([]utils.ReplaceCommand, error) {
-	processJsonLogger := jsonLogger.WithPrefix("ProcessJSON").WithField("commandName", command.Name).WithField("file", filename)
-	processJsonLogger.Debug("Starting JSON processing for file")
-	processJsonLogger.Trace("Initial file content length: %d", len(content))
+	processJSONLogger := jsonLogger.WithPrefix("ProcessJSON").WithField("commandName", command.Name).WithField("file", filename)
+	processJSONLogger.Debug("Starting JSON processing for file")
+	processJSONLogger.Trace("Initial file content length: %d", len(content))
 
 	var commands []utils.ReplaceCommand
 	startTime := time.Now()
@@ -26,15 +32,15 @@ func ProcessJSON(content string, command utils.ModifyCommand, filename string) (
 	var jsonData interface{}
 	err := json.Unmarshal([]byte(content), &jsonData)
 	if err != nil {
-		processJsonLogger.Error("Failed to parse JSON content: %v", err)
+		processJSONLogger.Error("Failed to parse JSON content: %v", err)
 		return commands, fmt.Errorf("failed to parse JSON: %v", err)
 	}
-	processJsonLogger.Debug("Successfully parsed JSON content")
+	processJSONLogger.Debug("Successfully parsed JSON content")
 
 	// Create Lua state
 	L, err := NewLuaState()
 	if err != nil {
-		processJsonLogger.Error("Error creating Lua state: %v", err)
+		processJSONLogger.Error("Error creating Lua state: %v", err)
 		return commands, fmt.Errorf("error creating Lua state: %v", err)
 	}
 	defer L.Close()
@@ -45,66 +51,486 @@ func ProcessJSON(content string, command utils.ModifyCommand, filename string) (
 	// Convert JSON data to Lua table
 	luaTable, err := ToLuaTable(L, jsonData)
 	if err != nil {
-		processJsonLogger.Error("Failed to convert JSON to Lua table: %v", err)
+		processJSONLogger.Error("Failed to convert JSON to Lua table: %v", err)
 		return commands, fmt.Errorf("failed to convert JSON to Lua table: %v", err)
 	}
 
 	// Set the JSON data as a global variable
 	L.SetGlobal("data", luaTable)
-	processJsonLogger.Debug("Set JSON data as Lua global 'data'")
+	processJSONLogger.Debug("Set JSON data as Lua global 'data'")
 
 	// Build and execute Lua script for JSON mode
 	luaExpr := BuildJSONLuaScript(command.Lua)
-	processJsonLogger.Debug("Built Lua script from expression: %q", command.Lua)
-	processJsonLogger.Trace("Full Lua script: %q", utils.LimitString(luaExpr, 200))
+	processJSONLogger.Debug("Built Lua script from expression: %q", command.Lua)
+	processJSONLogger.Trace("Full Lua script: %q", utils.LimitString(luaExpr, 200))
 
 	if err := L.DoString(luaExpr); err != nil {
-		processJsonLogger.Error("Lua script execution failed: %v\nScript: %s", err, utils.LimitString(luaExpr, 200))
+		processJSONLogger.Error("Lua script execution failed: %v\nScript: %s", err, utils.LimitString(luaExpr, 200))
 		return commands, fmt.Errorf("lua script execution failed: %v", err)
 	}
-	processJsonLogger.Debug("Lua script executed successfully")
+	processJSONLogger.Debug("Lua script executed successfully")
 
 	// Check if modification flag is set
 	modifiedVal := L.GetGlobal("modified")
 	if modifiedVal.Type() != lua.LTBool || !lua.LVAsBool(modifiedVal) {
-		processJsonLogger.Debug("Skipping - no modifications indicated by Lua script")
+		processJSONLogger.Debug("Skipping - no modifications indicated by Lua script")
 		return commands, nil
 	}
 
 	// Get the modified data from Lua
 	modifiedData := L.GetGlobal("data")
 	if modifiedData.Type() != lua.LTTable {
-		processJsonLogger.Error("Expected 'data' to be a table after Lua processing, got %s", modifiedData.Type().String())
+		processJSONLogger.Error("Expected 'data' to be a table after Lua processing, got %s", modifiedData.Type().String())
 		return commands, fmt.Errorf("expected 'data' to be a table after Lua processing")
 	}
 
 	// Convert back to Go interface
 	goData, err := FromLua(L, modifiedData)
 	if err != nil {
-		processJsonLogger.Error("Failed to convert Lua table back to Go: %v", err)
+		processJSONLogger.Error("Failed to convert Lua table back to Go: %v", err)
 		return commands, fmt.Errorf("failed to convert Lua table back to Go: %v", err)
 	}
 
-	// Marshal back to JSON
-	modifiedJSON, err := json.MarshalIndent(goData, "", "  ")
+	processJSONLogger.Debug("About to call applyChanges with original data and modified data")
+	commands, err = applyChanges(content, jsonData, goData)
 	if err != nil {
-		processJsonLogger.Error("Failed to marshal modified data to JSON: %v", err)
-		return commands, fmt.Errorf("failed to marshal modified data to JSON: %v", err)
+		processJSONLogger.Error("Failed to apply surgical JSON changes: %v", err)
+		return commands, fmt.Errorf("failed to apply surgical JSON changes: %v", err)
 	}
 
-	// Create replacement command for the entire file
-	// For JSON mode, we always replace the entire content
-	commands = append(commands, utils.ReplaceCommand{
-		From: 0,
-		To:   len(content),
-		With: string(modifiedJSON),
+	processJSONLogger.Debug("Total JSON processing time: %v", time.Since(startTime))
+	processJSONLogger.Debug("Generated %d total modifications", len(commands))
+	return commands, nil
+}
+
+// applyChanges attempts to make surgical changes while preserving exact formatting
+func applyChanges(content string, originalData, modifiedData interface{}) ([]utils.ReplaceCommand, error) {
+	var commands []utils.ReplaceCommand
+
+	// Find all changes between original and modified data
+	changes := findDeepChanges("", originalData, modifiedData)
+
+	jsonLogger.Debug("applyChanges: Found %d changes: %v", len(changes), changes)
+
+	if len(changes) == 0 {
+		return commands, nil
+	}
+
+	// Sort removal operations by index in descending order to avoid index shifting
+	var removals []string
+	var additions []string
+	var valueChanges []string
+
+	for path := range changes {
+		if strings.HasSuffix(path, "@remove") {
+			removals = append(removals, path)
+		} else if strings.HasSuffix(path, "@add") {
+			additions = append(additions, path)
+		} else {
+			valueChanges = append(valueChanges, path)
+		}
+	}
+
+	jsonLogger.Debug("applyChanges: %d removals, %d additions, %d value changes", len(removals), len(additions), len(valueChanges))
+
+	// Apply removals first (from end to beginning to avoid index shifting)
+	for _, removalPath := range removals {
+		actualPath := strings.TrimSuffix(removalPath, "@remove")
+		elementIndex := extractIndexFromRemovalPath(actualPath)
+		arrayPath := getArrayPathFromElementPath(actualPath)
+
+		jsonLogger.Debug("Processing removal: path=%s, index=%d, arrayPath=%s", actualPath, elementIndex, arrayPath)
+
+		// Find the exact byte range to remove
+		from, to := findArrayElementRemovalRange(content, arrayPath, elementIndex)
+
+		jsonLogger.Debug("Removing bytes %d-%d", from, to)
+
+		commands = append(commands, utils.ReplaceCommand{
+			From: from,
+			To:   to,
+			With: "",
+		})
+
+		jsonLogger.Debug("Added removal command: From=%d, To=%d, With=\"\"", from, to)
+	}
+
+	// Apply additions (new fields)
+	for _, additionPath := range additions {
+		actualPath := strings.TrimSuffix(additionPath, "@add")
+		newValue := changes[additionPath]
+
+		jsonLogger.Debug("Processing addition: path=%s, value=%v", actualPath, newValue)
+
+		// Find the parent object to add the field to
+		parentPath := getParentPath(actualPath)
+		fieldName := getFieldName(actualPath)
+
+		jsonLogger.Debug("Parent path: %s, field name: %s", parentPath, fieldName)
+
+		// Get the parent object
+		var parentResult gjson.Result
+		if parentPath == "" {
+			// Adding to root object - get the entire JSON
+			parentResult = gjson.Parse(content)
+		} else {
+			parentResult = gjson.Get(content, parentPath)
+		}
+
+		if !parentResult.Exists() {
+			jsonLogger.Debug("Parent path %s does not exist, skipping", parentPath)
+			continue
+		}
+
+		// Find where to insert the new field (at the end of the object)
+		startPos := int(parentResult.Index + len(parentResult.Raw) - 1) // Before closing brace
+
+		jsonLogger.Debug("Inserting at pos %d", startPos)
+
+		// Convert the new value to JSON string
+		newValueStr := convertValueToJSONString(newValue)
+
+		// Insert the new field with pretty-printed formatting
+		// Format: ,"fieldName": { ... }
+		insertText := fmt.Sprintf(`,"%s": %s`, fieldName, newValueStr)
+
+		commands = append(commands, utils.ReplaceCommand{
+			From: startPos,
+			To:   startPos,
+			With: insertText,
+		})
+
+		jsonLogger.Debug("Added addition command: From=%d, To=%d, With=%q", startPos, startPos, insertText)
+	}
+
+	// Apply value changes (in reverse order to avoid position shifting)
+	sort.Slice(valueChanges, func(i, j int) bool {
+		// Get positions for comparison
+		resultI := gjson.Get(content, valueChanges[i])
+		resultJ := gjson.Get(content, valueChanges[j])
+		return resultI.Index > resultJ.Index // Descending order
 	})
 
-	processJsonLogger.Debug("Total JSON processing time: %v", time.Since(startTime))
-	processJsonLogger.Debug("Generated %d total modifications", len(commands))
+	for _, path := range valueChanges {
+		newValue := changes[path]
+
+		jsonLogger.Debug("Processing value change: path=%s, value=%v", path, newValue)
+
+		// Get the current value and its position in the original JSON
+		result := gjson.Get(content, path)
+		if !result.Exists() {
+			jsonLogger.Debug("Path %s does not exist, skipping", path)
+			continue // Skip if path doesn't exist
+		}
+
+		// Get the exact byte positions of this value
+		startPos := result.Index
+		endPos := startPos + len(result.Raw)
+
+		jsonLogger.Debug("Found value at pos %d-%d: %q", startPos, endPos, result.Raw)
+
+		// Convert the new value to JSON string
+		newValueStr := convertValueToJSONString(newValue)
+
+		jsonLogger.Debug("Converting to: %q", newValueStr)
+
+		// Create a replacement command for this specific value
+		commands = append(commands, utils.ReplaceCommand{
+			From: int(startPos),
+			To:   int(endPos),
+			With: newValueStr,
+		})
+
+		jsonLogger.Debug("Added command: From=%d, To=%d, With=%q", int(startPos), int(endPos), newValueStr)
+	}
+
 	return commands, nil
 }
 
+// extractIndexFromRemovalPath extracts the array index from a removal path like "Rows.0.Inputs.1@remove"
+func extractIndexFromRemovalPath(path string) int {
+	parts := strings.Split(strings.TrimSuffix(path, "@remove"), ".")
+	if len(parts) > 0 {
+		lastPart := parts[len(parts)-1]
+		if index, err := strconv.Atoi(lastPart); err == nil {
+			return index
+		}
+	}
+	return -1
+}
+
+// getArrayPathFromElementPath converts "Rows.0.Inputs.1" to "Rows.0.Inputs"
+func getArrayPathFromElementPath(elementPath string) string {
+	parts := strings.Split(elementPath, ".")
+	if len(parts) > 0 {
+		return strings.Join(parts[:len(parts)-1], ".")
+	}
+	return ""
+}
+
+// getParentPath extracts the parent path from a full path like "Rows.0.Inputs.1"
+func getParentPath(fullPath string) string {
+	parts := strings.Split(fullPath, ".")
+	if len(parts) > 0 {
+		return strings.Join(parts[:len(parts)-1], ".")
+	}
+	return ""
+}
+
+// getFieldName extracts the field name from a full path like "Rows.0.Inputs.1"
+func getFieldName(fullPath string) string {
+	parts := strings.Split(fullPath, ".")
+	if len(parts) > 0 {
+		return parts[len(parts)-1]
+	}
+	return ""
+}
+
+// convertValueToJSONString converts a Go interface{} to a JSON string representation
+func convertValueToJSONString(value interface{}) string {
+	switch v := value.(type) {
+	case string:
+		return `"` + strings.ReplaceAll(v, `"`, `\"`) + `"`
+	case float64:
+		if v == float64(int64(v)) {
+			return strconv.FormatInt(int64(v), 10)
+		}
+		return strconv.FormatFloat(v, 'f', -1, 64)
+	case bool:
+		return strconv.FormatBool(v)
+	case nil:
+		return "null"
+	case map[string]interface{}:
+		// Handle maps specially to avoid double-escaping of keys
+		var pairs []string
+		for key, val := range v {
+			// The key might already have escaped quotes from Lua, so we need to be careful
+			// If the key already contains escaped quotes, we need to unescape them first
+			keyStr := key
+			if strings.Contains(key, `\"`) {
+				// Key already has escaped quotes, use it as-is
+				keyStr = `"` + key + `"`
+			} else {
+				// Normal key, escape quotes
+				keyStr = `"` + strings.ReplaceAll(key, `"`, `\"`) + `"`
+			}
+			valStr := convertValueToJSONString(val)
+			pairs = append(pairs, keyStr+":"+valStr)
+		}
+		return "{" + strings.Join(pairs, ",") + "}"
+	default:
+		// For other complex types (arrays), we need to use json.Marshal
+		jsonBytes, err := json.Marshal(v)
+		if err != nil {
+			return "null" // Fallback to null if marshaling fails
+		}
+		return string(jsonBytes)
+	}
+}
+
+// findArrayElementRemovalRange finds the exact byte range to remove for an array element
+func findArrayElementRemovalRange(content, arrayPath string, elementIndex int) (int, int) {
+	// Get the array using gjson
+	arrayResult := gjson.Get(content, arrayPath)
+	if !arrayResult.Exists() || !arrayResult.IsArray() {
+		return -1, -1
+	}
+
+	// Get all array elements
+	elements := arrayResult.Array()
+	if elementIndex >= len(elements) {
+		return -1, -1
+	}
+
+	// Get the target element
+	elementResult := elements[elementIndex]
+	startPos := int(elementResult.Index)
+	endPos := int(elementResult.Index + len(elementResult.Raw))
+
+	// Handle comma removal properly
+	if elementIndex == 0 && len(elements) > 1 {
+		// First element but not the only one - remove comma after
+		for i := endPos; i < len(content) && i < endPos+50; i++ {
+			if content[i] == ',' {
+				endPos = i + 1
+				break
+			}
+		}
+	} else if elementIndex == len(elements)-1 && len(elements) > 1 {
+		// Last element and not the only one - remove comma before
+		prevElementEnd := int(elements[elementIndex-1].Index + len(elements[elementIndex-1].Raw))
+		for i := prevElementEnd; i < startPos && i < len(content); i++ {
+			if content[i] == ',' {
+				startPos = i
+				break
+			}
+		}
+	}
+	// If it's the only element, don't remove any commas
+
+	return startPos, endPos
+}
+
+// findDeepChanges recursively finds all paths that need to be changed
+func findDeepChanges(basePath string, original, modified interface{}) map[string]interface{} {
+	changes := make(map[string]interface{})
+
+	switch orig := original.(type) {
+	case map[string]interface{}:
+		if mod, ok := modified.(map[string]interface{}); ok {
+			// Check for new keys added in modified data
+			for key, modValue := range mod {
+				var currentPath string
+				if basePath == "" {
+					currentPath = key
+				} else {
+					currentPath = basePath + "." + key
+				}
+
+				if origValue, exists := orig[key]; exists {
+					// Key exists in both, check if value changed
+					switch modValue.(type) {
+					case map[string]interface{}, []interface{}:
+						// Recursively check nested structures
+						nestedChanges := findDeepChanges(currentPath, origValue, modValue)
+						for nestedPath, nestedValue := range nestedChanges {
+							changes[nestedPath] = nestedValue
+						}
+					default:
+						// Primitive value - check if changed
+						if !deepEqual(origValue, modValue) {
+							changes[currentPath] = modValue
+						}
+					}
+				} else {
+					// New key added - mark for addition
+					changes[currentPath+"@add"] = modValue
+				}
+			}
+		}
+	case []interface{}:
+		if mod, ok := modified.([]interface{}); ok {
+			// Handle array changes by detecting specific element operations
+			if len(orig) != len(mod) {
+				// Array length changed - detect if it's element removal
+				if len(orig) > len(mod) {
+					// Element(s) removed - find which ones by comparing content
+					removedIndices := findRemovedArrayElements(orig, mod)
+					for _, removedIndex := range removedIndices {
+						var currentPath string
+						if basePath == "" {
+							currentPath = fmt.Sprintf("%d@remove", removedIndex)
+						} else {
+							currentPath = fmt.Sprintf("%s.%d@remove", basePath, removedIndex)
+						}
+						changes[currentPath] = nil // Mark for removal
+					}
+				}
+			} else {
+				// Same length - check individual elements for value changes
+				for i, modValue := range mod {
+					var currentPath string
+					if basePath == "" {
+						currentPath = strconv.Itoa(i)
+					} else {
+						currentPath = basePath + "." + strconv.Itoa(i)
+					}
+
+					if i < len(orig) {
+						// Index exists in both, check if value changed
+						switch modValue.(type) {
+						case map[string]interface{}, []interface{}:
+							// Recursively check nested structures
+							nestedChanges := findDeepChanges(currentPath, orig[i], modValue)
+							for nestedPath, nestedValue := range nestedChanges {
+								changes[nestedPath] = nestedValue
+							}
+						default:
+							// Primitive value - check if changed
+							if !deepEqual(orig[i], modValue) {
+								changes[currentPath] = modValue
+							}
+						}
+					}
+				}
+			}
+		}
+	default:
+		// For primitive types, compare directly
+		if !deepEqual(original, modified) {
+			if basePath == "" {
+				changes[""] = modified
+			} else {
+				changes[basePath] = modified
+			}
+		}
+	}
+
+	return changes
+}
+
+// findRemovedArrayElements compares two arrays and returns indices of removed elements
+func findRemovedArrayElements(original, modified []interface{}) []int {
+	var removedIndices []int
+
+	// Simple approach: find elements in original that don't exist in modified
+	for i, origElement := range original {
+		found := false
+		for _, modElement := range modified {
+			if deepEqual(origElement, modElement) {
+				found = true
+				break
+			}
+		}
+		if !found {
+			removedIndices = append(removedIndices, i)
+		}
+	}
+
+	return removedIndices
+}
+
+// deepEqual performs deep comparison of two values
+func deepEqual(a, b interface{}) bool {
+	if a == nil && b == nil {
+		return true
+	}
+	if a == nil || b == nil {
+		return false
+	}
+
+	switch av := a.(type) {
+	case map[string]interface{}:
+		if bv, ok := b.(map[string]interface{}); ok {
+			if len(av) != len(bv) {
+				return false
+			}
+			for k, v := range av {
+				if !deepEqual(v, bv[k]) {
+					return false
+				}
+			}
+			return true
+		}
+		return false
+	case []interface{}:
+		if bv, ok := b.([]interface{}); ok {
+			if len(av) != len(bv) {
+				return false
+			}
+			for i, v := range av {
+				if !deepEqual(v, bv[i]) {
+					return false
+				}
+			}
+			return true
+		}
+		return false
+	default:
+		return a == b
+	}
+}
+
 // ToLuaTable converts a Go interface{} to a Lua table recursively
 func ToLuaTable(L *lua.LState, data interface{}) (*lua.LTable, error) {
 	toLuaTableLogger := jsonLogger.WithPrefix("ToLuaTable")

processor/json_test.go

@@ -16,46 +16,25 @@ func TestProcessJSON(t *testing.T) {
 		expectedMods   int
 	}{
 		{
-			name:          "Basic JSON object modification",
-			input:         `{"name": "test", "value": 42}`,
-			luaExpression: `data.value = data.value * 2; return true`,
-			expectedOutput: `{
-  "name": "test",
-  "value": 84
-}`,
-			expectedMods: 1,
+			name:           "Basic JSON object modification",
+			input:          `{"name": "test", "value": 42}`,
+			luaExpression:  `data.value = data.value * 2; return true`,
+			expectedOutput: `{"name": "test", "value": 84}`,
+			expectedMods:   1,
 		},
 		{
-			name:          "JSON array modification",
-			input:         `{"items": [{"id": 1, "value": 10}, {"id": 2, "value": 20}]}`,
-			luaExpression: `for i, item in ipairs(data.items) do data.items[i].value = item.value * 1.5 end; return true`,
-			expectedOutput: `{
-  "items": [
-    {
-      "id": 1,
-      "value": 15
-    },
-    {
-      "id": 2,
-      "value": 30
-    }
-  ]
-}`,
-			expectedMods: 1,
+			name:           "JSON array modification",
+			input:          `{"items": [{"name": "item1", "value": 10}, {"name": "item2", "value": 20}]}`,
+			luaExpression:  `for i, item in ipairs(data.items) do item.value = item.value * 2 end modified = true`,
+			expectedOutput: `{"items": [{"name": "item1", "value": 20}, {"name": "item2", "value": 40}]}`,
+			expectedMods:   2, 
 		},
 		{
-			name:          "JSON nested object modification",
-			input:         `{"config": {"settings": {"enabled": false, "timeout": 30}}}`,
-			luaExpression: `data.config.settings.enabled = true; data.config.settings.timeout = 60; return true`,
-			expectedOutput: `{
-  "config": {
-    "settings": {
-      "enabled": true,
-      "timeout": 60
-    }
-  }
-}`,
-			expectedMods: 1,
+			name:           "JSON nested object modification",
+			input:          `{"config": {"setting1": {"enabled": true, "value": 5}, "setting2": {"enabled": false, "value": 10}}}`,
+			luaExpression:  `data.config.setting1.enabled = false data.config.setting2.value = 15 modified = true`,
+			expectedOutput: `{"config": {"setting1": {"enabled": false, "value": 5}, "setting2": {"enabled": false, "value": 15}}}`,
+			expectedMods:   2,
 		},
 		{
 			name:           "JSON no modification",

processor/luahelper-test-regress.lua

@@ -0,0 +1,43 @@
+-- Load the helper script
+dofile("luahelper.lua")
+
+-- Test helper function
+local function assert(condition, message)
+	if not condition then error("ASSERTION FAILED: " .. (message or "unknown error")) end
+end
+
+local function test(name, fn)
+	local ok, err = pcall(fn)
+	if ok then
+		print("PASS: " .. name)
+	else
+		print("FAIL: " .. name .. " - " .. tostring(err))
+	end
+end
+
+test("regression test 001", function()
+	local csv =
+		[[Id	Enabled	ModuleId	DepartmentId	IsDepartment	PositionInGraph	Parents	Modifiers	UpgradePrice
+news_department	TRUE	navigation		TRUE	2 0		NewsAnalyticsDepartment + 1	communication_relay communication_relay
+nd_charge_bonus	TRUE	navigation	news_department	FALSE	1 0	news_department	NDSkillChargeBonus + 1	expert_disk expert_disk
+nd_cooldown_time_reduce	TRUE	navigation	news_department	FALSE	3 0	news_department	NDCooldownTimeReduce - 2	communication_relay communication_relay]]
+	local rows, err = fromCSV(csv, { delimiter = "\t", hasheader = true, hascomments = true })
+	if err then error("fromCSV error: " .. err) end
+	assert(#rows == 3, "Should have 3 rows")
+	assert(rows[1].Id == "news_department", "First row Id should be 'news_department'")
+	assert(rows[1].Enabled == "TRUE", "First row Enabled should be 'TRUE'")
+	assert(rows[1].ModuleId == "navigation", "First row ModuleId should be 'navigation'")
+	assert(rows[1].DepartmentId == "", "First row DepartmentId should be ''")
+	assert(rows[1].IsDepartment == "TRUE", "First row IsDepartment should be 'TRUE'")
+	assert(rows.Headers[1] == "Id", "First row Headers should be 'Id'")
+	assert(rows.Headers[2] == "Enabled", "First row Headers should be 'Enabled'")
+	assert(rows.Headers[3] == "ModuleId", "First row Headers should be 'ModuleId'")
+	assert(rows.Headers[4] == "DepartmentId", "First row Headers should be 'DepartmentId'")
+	assert(rows.Headers[5] == "IsDepartment", "First row Headers should be 'IsDepartment'")
+	assert(rows.Headers[6] == "PositionInGraph", "First row Headers should be 'PositionInGraph'")
+	assert(rows.Headers[7] == "Parents", "First row Headers should be 'Parents'")
+	assert(rows.Headers[8] == "Modifiers", "First row Headers should be 'Modifiers'")
+	assert(rows.Headers[9] == "UpgradePrice", "First row Headers should be 'UpgradePrice'")
+end)
+
+print("\nAll tests completed!")

processor/luahelper-test.lua

@@ -0,0 +1,534 @@
+-- Load the helper script
+dofile("luahelper.lua")
+
+-- Test helper function
+local function assert(condition, message)
+	if not condition then error("ASSERTION FAILED: " .. (message or "unknown error")) end
+end
+
+local function test(name, fn)
+	local ok, err = pcall(fn)
+	if ok then
+		print("PASS: " .. name)
+	else
+		print("FAIL: " .. name .. " - " .. tostring(err))
+	end
+end
+
+-- Test fromCSV option validation
+test("fromCSV invalid option", function()
+	local csv = "a,b,c\n1,2,3"
+	local ok, errMsg = pcall(function() fromCSV(csv, { invalidOption = true }) end)
+	assert(ok == false, "Should raise error")
+	assert(string.find(errMsg, "unknown option"), "Error should mention unknown option")
+end)
+
+-- Test toCSV invalid delimiter
+test("toCSV invalid delimiter", function()
+	local rows = { { "a", "b", "c" } }
+	local csv = toCSV(rows, { delimiter = 123 })
+	-- toCSV converts delimiter to string, so 123 becomes "123"
+	assert(csv == "a123b123c", "Should convert delimiter to string")
+end)
+
+-- Test fromCSV basic parsing
+test("fromCSV basic", function()
+	local csv = "a,b,c\n1,2,3\n4,5,6"
+	local rows = fromCSV(csv)
+	assert(#rows == 3, "Should have 3 rows")
+	assert(rows[1][1] == "a", "First row first field should be 'a'")
+	assert(rows[2][2] == "2", "Second row second field should be '2'")
+end)
+
+-- Test fromCSV with headers
+test("fromCSV with headers", function()
+	local csv = "foo,bar,baz\n1,2,3\n4,5,6"
+	local rows = fromCSV(csv, { hasheader = true })
+	assert(#rows == 2, "Should have 2 data rows")
+	assert(rows[1][1] == "1", "First row first field should be '1'")
+	assert(rows[1].foo == "1", "First row foo should be '1'")
+	assert(rows[1].bar == "2", "First row bar should be '2'")
+	assert(rows[1].baz == "3", "First row baz should be '3'")
+end)
+
+-- Test fromCSV with custom delimiter
+test("fromCSV with tab delimiter", function()
+	local csv = "a\tb\tc\n1\t2\t3"
+	local rows = fromCSV(csv, { delimiter = "\t" })
+	assert(#rows == 2, "Should have 2 rows")
+	assert(rows[1][1] == "a", "First row first field should be 'a'")
+	assert(rows[2][2] == "2", "Second row second field should be '2'")
+end)
+
+-- Test fromCSV with quoted fields
+test("fromCSV with quoted fields", function()
+	local csv = '"hello,world","test"\n"foo","bar"'
+	local rows = fromCSV(csv)
+	assert(#rows == 2, "Should have 2 rows")
+	assert(rows[1][1] == "hello,world", "Quoted field with comma should be preserved")
+	assert(rows[1][2] == "test", "Second field should be 'test'")
+end)
+
+-- Test toCSV basic
+test("toCSV basic", function()
+	local rows = { { "a", "b", "c" }, { "1", "2", "3" } }
+	local csv = toCSV(rows)
+	assert(csv == "a,b,c\n1,2,3", "CSV output should match expected")
+end)
+
+-- Test toCSV with custom delimiter
+test("toCSV with tab delimiter", function()
+	local rows = { { "a", "b", "c" }, { "1", "2", "3" } }
+	local csv = toCSV(rows, { delimiter = "\t" })
+	assert(csv == "a\tb\tc\n1\t2\t3", "TSV output should match expected")
+end)
+
+-- Test toCSV with fields needing quoting
+test("toCSV with quoted fields", function()
+	local rows = { { "hello,world", "test" }, { "foo", "bar" } }
+	local csv = toCSV(rows)
+	assert(csv == '"hello,world",test\nfoo,bar', "Fields with commas should be quoted")
+end)
+
+-- Test round trip
+test("fromCSV toCSV round trip", function()
+	local original = "a,b,c\n1,2,3\n4,5,6"
+	local rows = fromCSV(original)
+	local csv = toCSV(rows)
+	assert(csv == original, "Round trip should preserve original")
+end)
+
+-- Test round trip with headers
+test("fromCSV toCSV round trip with headers", function()
+	local original = "foo,bar,baz\n1,2,3\n4,5,6"
+	local rows = fromCSV(original, { hasheader = true })
+	local csv = toCSV(rows)
+	local expected = "1,2,3\n4,5,6"
+	assert(csv == expected, "Round trip with headers should preserve data rows")
+end)
+
+-- Test fromCSV with comments
+test("fromCSV with comments", function()
+	local csv = "# This is a comment\nfoo,bar,baz\n1,2,3\n# Another comment\n4,5,6"
+	local rows = fromCSV(csv, { hascomments = true })
+	assert(#rows == 3, "Should have 3 rows (comments filtered, header + 2 data rows)")
+	assert(rows[1][1] == "foo", "First row should be header row")
+	assert(rows[2][1] == "1", "Second row first field should be '1'")
+	assert(rows[3][1] == "4", "Third row first field should be '4'")
+end)
+
+-- Test fromCSV with comments and headers
+test("fromCSV with comments and headers", function()
+	local csv = "#mercenary_profiles\nId,Name,Value\n1,Test,100\n# End of data\n2,Test2,200"
+	local rows = fromCSV(csv, { hasheader = true, hascomments = true })
+	assert(#rows == 2, "Should have 2 data rows")
+	assert(rows[1].Id == "1", "First row Id should be '1'")
+	assert(rows[1].Name == "Test", "First row Name should be 'Test'")
+	assert(rows[1].Value == "100", "First row Value should be '100'")
+	assert(rows[2].Id == "2", "Second row Id should be '2'")
+end)
+
+-- Test fromCSV with comments disabled
+test("fromCSV without comments", function()
+	local csv = "# This should not be filtered\nfoo,bar\n1,2"
+	local rows = fromCSV(csv, { hascomments = false })
+	assert(#rows == 3, "Should have 3 rows (including comment)")
+	assert(rows[1][1] == "# This should not be filtered", "Comment line should be preserved")
+end)
+
+-- Test fromCSV with comment at start
+test("fromCSV comment at start", function()
+	local csv = "# Header comment\nId,Name\n1,Test"
+	local rows = fromCSV(csv, { hascomments = true })
+	assert(#rows == 2, "Should have 2 rows (comment filtered)")
+	assert(rows[1][1] == "Id", "First row should be header")
+end)
+
+-- Test fromCSV with comment with leading whitespace
+test("fromCSV comment with whitespace", function()
+	local csv = "  # Comment with spaces\nId,Name\n1,Test"
+	local rows = fromCSV(csv, { hascomments = true })
+	assert(#rows == 2, "Should have 2 rows (comment with spaces filtered)")
+	assert(rows[1][1] == "Id", "First row should be header")
+end)
+
+-- Test fromCSV with comment with tabs
+test("fromCSV comment with tabs", function()
+	local csv = "\t# Comment with tab\nId,Name\n1,Test"
+	local rows = fromCSV(csv, { hascomments = true })
+	assert(#rows == 2, "Should have 2 rows (comment with tab filtered)")
+	assert(rows[1][1] == "Id", "First row should be header")
+end)
+
+-- Test fromCSV with multiple consecutive comments
+test("fromCSV multiple consecutive comments", function()
+	local csv = "# First comment\n# Second comment\n# Third comment\nId,Name\n1,Test"
+	local rows = fromCSV(csv, { hascomments = true })
+	assert(#rows == 2, "Should have 2 rows (all comments filtered)")
+	assert(rows[1][1] == "Id", "First row should be header")
+end)
+
+-- Test fromCSV with comment in middle of data
+test("fromCSV comment in middle", function()
+	local csv = "Id,Name\n1,Test\n# Middle comment\n2,Test2"
+	local rows = fromCSV(csv, { hascomments = true })
+	assert(#rows == 3, "Should have 3 rows (comment filtered)")
+	assert(rows[1][1] == "Id", "First row should be header")
+	assert(rows[2][1] == "1", "Second row should be first data")
+	assert(rows[3][1] == "2", "Third row should be second data")
+end)
+
+-- Test fromCSV with comment at end
+test("fromCSV comment at end", function()
+	local csv = "Id,Name\n1,Test\n# End comment"
+	local rows = fromCSV(csv, { hascomments = true })
+	assert(#rows == 2, "Should have 2 rows (end comment filtered)")
+	assert(rows[1][1] == "Id", "First row should be header")
+	assert(rows[2][1] == "1", "Second row should be data")
+end)
+
+-- Test fromCSV with empty comment line
+test("fromCSV empty comment", function()
+	local csv = "#\nId,Name\n1,Test"
+	local rows = fromCSV(csv, { hascomments = true })
+	assert(#rows == 2, "Should have 2 rows (empty comment filtered)")
+	assert(rows[1][1] == "Id", "First row should be header")
+end)
+
+-- Test fromCSV with comment and headers
+test("fromCSV comment with headers enabled", function()
+	local csv = "#mercenary_profiles\nId,Name,Value\n1,Test,100\n2,Test2,200"
+	local rows = fromCSV(csv, { hasheader = true, hascomments = true })
+	assert(#rows == 2, "Should have 2 data rows")
+	assert(rows[1].Id == "1", "First row Id should be '1'")
+	assert(rows[1].Name == "Test", "First row Name should be 'Test'")
+	assert(rows[2].Id == "2", "Second row Id should be '2'")
+end)
+
+-- Test fromCSV with comment and TSV delimiter
+test("fromCSV comment with tab delimiter", function()
+	local csv = "# Comment\nId\tName\n1\tTest"
+	local rows = fromCSV(csv, { delimiter = "\t", hascomments = true })
+	assert(#rows == 2, "Should have 2 rows")
+	assert(rows[1][1] == "Id", "First row should be header")
+	assert(rows[2][1] == "1", "Second row first field should be '1'")
+end)
+
+-- Test fromCSV with comment and headers and TSV
+test("fromCSV comment with headers and TSV", function()
+	local csv = "#mercenary_profiles\nId\tName\tValue\n1\tTest\t100"
+	local rows = fromCSV(csv, { delimiter = "\t", hasheader = true, hascomments = true })
+	assert(#rows == 1, "Should have 1 data row")
+	assert(rows[1].Id == "1", "Row Id should be '1'")
+	assert(rows[1].Name == "Test", "Row Name should be 'Test'")
+	assert(rows[1].Value == "100", "Row Value should be '100'")
+end)
+
+-- Test fromCSV with data field starting with # (not a comment)
+test("fromCSV data field starting with hash", function()
+	local csv = "Id,Name\n1,#NotAComment\n2,Test"
+	local rows = fromCSV(csv, { hascomments = true })
+	assert(#rows == 3, "Should have 3 rows (data with # not filtered)")
+	assert(rows[1][1] == "Id", "First row should be header")
+	assert(rows[2][2] == "#NotAComment", "Second row should have #NotAComment as data")
+end)
+
+-- Test fromCSV with quoted field starting with #
+test("fromCSV quoted field with hash", function()
+	local csv = 'Id,Name\n1,"#NotAComment"\n2,Test'
+	local rows = fromCSV(csv, { hascomments = true })
+	assert(#rows == 3, "Should have 3 rows (quoted # not filtered)")
+	assert(rows[2][2] == "#NotAComment", "Quoted field with # should be preserved")
+end)
+
+-- Test fromCSV with comment after quoted field
+test("fromCSV comment after quoted field", function()
+	local csv = 'Id,Name\n1,"Test"\n# This is a comment\n2,Test2'
+	local rows = fromCSV(csv, { hascomments = true })
+	assert(#rows == 3, "Should have 3 rows (comment filtered)")
+	assert(rows[2][2] == "Test", "Quoted field should be preserved")
+	assert(rows[3][1] == "2", "Third row should be second data row")
+end)
+
+-- Math function tests
+test("min function", function()
+	assert(min(5, 3) == 3, "min(5, 3) should be 3")
+	assert(min(-1, 0) == -1, "min(-1, 0) should be -1")
+	assert(min(10, 10) == 10, "min(10, 10) should be 10")
+end)
+
+test("max function", function()
+	assert(max(5, 3) == 5, "max(5, 3) should be 5")
+	assert(max(-1, 0) == 0, "max(-1, 0) should be 0")
+	assert(max(10, 10) == 10, "max(10, 10) should be 10")
+end)
+
+test("round function", function()
+	assert(round(3.14159) == 3, "round(3.14159) should be 3")
+	assert(round(3.14159, 2) == 3.14, "round(3.14159, 2) should be 3.14")
+	assert(round(3.5) == 4, "round(3.5) should be 4")
+	assert(round(3.4) == 3, "round(3.4) should be 3")
+	assert(round(123.456, 1) == 123.5, "round(123.456, 1) should be 123.5")
+end)
+
+test("floor function", function()
+	assert(floor(3.7) == 3, "floor(3.7) should be 3")
+	assert(floor(-3.7) == -4, "floor(-3.7) should be -4")
+	assert(floor(5) == 5, "floor(5) should be 5")
+end)
+
+test("ceil function", function()
+	assert(ceil(3.2) == 4, "ceil(3.2) should be 4")
+	assert(ceil(-3.2) == -3, "ceil(-3.2) should be -3")
+	assert(ceil(5) == 5, "ceil(5) should be 5")
+end)
+
+-- String function tests
+test("upper function", function()
+	assert(upper("hello") == "HELLO", "upper('hello') should be 'HELLO'")
+	assert(upper("Hello World") == "HELLO WORLD", "upper('Hello World') should be 'HELLO WORLD'")
+	assert(upper("123abc") == "123ABC", "upper('123abc') should be '123ABC'")
+end)
+
+test("lower function", function()
+	assert(lower("HELLO") == "hello", "lower('HELLO') should be 'hello'")
+	assert(lower("Hello World") == "hello world", "lower('Hello World') should be 'hello world'")
+	assert(lower("123ABC") == "123abc", "lower('123ABC') should be '123abc'")
+end)
+
+test("format function", function()
+	assert(format("Hello %s", "World") == "Hello World", "format should work")
+	assert(format("Number: %d", 42) == "Number: 42", "format with number should work")
+	assert(format("%.2f", 3.14159) == "3.14", "format with float should work")
+end)
+
+test("trim function", function()
+	assert(trim("  hello  ") == "hello", "trim should remove leading and trailing spaces")
+	assert(trim("  hello world  ") == "hello world", "trim should preserve internal spaces")
+	assert(trim("hello") == "hello", "trim should not affect strings without spaces")
+	assert(trim("   ") == "", "trim should handle all spaces")
+end)
+
+test("strsplit function", function()
+	local result = strsplit("a,b,c", ",")
+	assert(#result == 3, "strsplit should return 3 elements")
+	assert(result[1] == "a", "First element should be 'a'")
+	assert(result[2] == "b", "Second element should be 'b'")
+	assert(result[3] == "c", "Third element should be 'c'")
+end)
+
+test("strsplit with default separator", function()
+	local result = strsplit("a b c")
+	assert(#result == 3, "strsplit with default should return 3 elements")
+	assert(result[1] == "a", "First element should be 'a'")
+	assert(result[2] == "b", "Second element should be 'b'")
+	assert(result[3] == "c", "Third element should be 'c'")
+end)
+
+test("strsplit with custom separator", function()
+	local result = strsplit("a|b|c", "|")
+	assert(#result == 3, "strsplit with pipe should return 3 elements")
+	assert(result[1] == "a", "First element should be 'a'")
+	assert(result[2] == "b", "Second element should be 'b'")
+	assert(result[3] == "c", "Third element should be 'c'")
+end)
+
+-- Conversion function tests
+test("num function", function()
+	assert(num("123") == 123, "num('123') should be 123")
+	assert(num("45.67") == 45.67, "num('45.67') should be 45.67")
+	assert(num("invalid") == 0, "num('invalid') should be 0")
+	assert(num("") == 0, "num('') should be 0")
+end)
+
+test("str function", function()
+	assert(str(123) == "123", "str(123) should be '123'")
+	assert(str(45.67) == "45.67", "str(45.67) should be '45.67'")
+	assert(str(0) == "0", "str(0) should be '0'")
+end)
+
+test("is_number function", function()
+	assert(is_number("123") == true, "is_number('123') should be true")
+	assert(is_number("45.67") == true, "is_number('45.67') should be true")
+	assert(is_number("invalid") == false, "is_number('invalid') should be false")
+	assert(is_number("") == false, "is_number('') should be false")
+	assert(is_number("123abc") == false, "is_number('123abc') should be false")
+end)
+
+-- Table function tests
+test("isArray function", function()
+	assert(isArray({ 1, 2, 3 }) == true, "isArray should return true for sequential array")
+	assert(isArray({ "a", "b", "c" }) == true, "isArray should return true for string array")
+	assert(isArray({}) == true, "isArray should return true for empty array")
+	assert(isArray({ a = 1, b = 2 }) == false, "isArray should return false for map")
+	assert(isArray({ 1, 2, [4] = 4 }) == false, "isArray should return false for sparse array")
+	assert(
+		isArray({ [1] = 1, [2] = 2, [3] = 3 }) == true,
+		"isArray should return true for 1-indexed array"
+	)
+	assert(
+		isArray({ [0] = 1, [1] = 2 }) == false,
+		"isArray should return false for 0-indexed array"
+	)
+	assert(
+		isArray({ [1] = 1, [2] = 2, [4] = 4 }) == false,
+		"isArray should return false for non-sequential array"
+	)
+	assert(isArray("not a table") == false, "isArray should return false for non-table")
+	assert(isArray(123) == false, "isArray should return false for number")
+end)
+
+test("fromCSV assigns header keys correctly", function()
+	local teststr = [[
+#mercenary_profiles
+Id	ModifyStartCost	ModifyStep	ModifyLevelLimit	Health	ResistSheet	WoundSlots	MeleeDamage	MeleeAccuracy	RangeAccuracy	ReceiveAmputationChance	ReceiveWoundChanceMult	AttackWoundChanceMult	Dodge	Los	StarvationLimit	PainThresholdLimit	PainThresholdRegen	TalentPerkId	ActorId	SkinIndex	HairType	HairColorHex	VoiceBank	Immunity	CreatureClass
+john_hawkwood_boss	20	0.1		140	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 8 16 crit 1.60 critchance 0.05	0.5	0.5	0.03	0.5	1.2	0.3	8	2200	16	2	talent_the_man_who_sold_the_world	human_male	0	hair1	#633D08	player		Human
+francis_reid_daly	20	0.1		130	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 7 14 crit 1.70 critchance 0.05	0.5	0.4	0.04	0.9	1	0.3	8	2000	10	1	talent_weapon_durability	human_male	0			player		Human
+]]
+	local rows = fromCSV(teststr, { delimiter = "\t", hasheader = true, hascomments = true })
+	assert(#rows == 2, "Should have 2 data rows")
+
+	-- Test first row
+	assert(rows[1].Id == "john_hawkwood_boss", "First row Id should be 'john_hawkwood_boss'")
+	assert(rows[1].ModifyStartCost == "20", "First row ModifyStartCost should be '20'")
+	assert(rows[1].ModifyStep == "0.1", "First row ModifyStep should be '0.1'")
+	assert(rows[1].Health == "140", "First row Health should be '140'")
+	assert(rows[1].ActorId == "human_male", "First row ActorId should be 'human_male'")
+	assert(rows[1].HairColorHex == "#633D08", "First row HairColorHex should be '#633D08'")
+
+	-- Test second row
+	assert(rows[2].Id == "francis_reid_daly", "Second row Id should be 'francis_reid_daly'")
+	assert(rows[2].ModifyStartCost == "20", "Second row ModifyStartCost should be '20'")
+	assert(rows[2].ModifyStep == "0.1", "Second row ModifyStep should be '0.1'")
+	assert(rows[2].Health == "130", "Second row Health should be '130'")
+	assert(rows[2].ActorId == "human_male", "Second row ActorId should be 'human_male'")
+
+	-- Test that numeric indices still work
+	assert(rows[1][1] == "john_hawkwood_boss", "First row first field by index should work")
+	assert(rows[1][2] == "20", "First row second field by index should work")
+end)
+
+test("fromCSV debug header assignment", function()
+	local csv = "Id	Name	Value\n1	Test	100\n2	Test2	200"
+	local rows = fromCSV(csv, { delimiter = "\t", hasheader = true })
+	assert(rows[1].Id == "1", "Id should be '1'")
+	assert(rows[1].Name == "Test", "Name should be 'Test'")
+	assert(rows[1].Value == "100", "Value should be '100'")
+end)
+
+test("fromCSV real world mercenary file format", function()
+	local csv = [[#mercenary_profiles
+Id	ModifyStartCost	ModifyStep	ModifyLevelLimit	Health	ResistSheet	WoundSlots	MeleeDamage	MeleeAccuracy	RangeAccuracy	ReceiveAmputationChance	ReceiveWoundChanceMult	AttackWoundChanceMult	Dodge	Los	StarvationLimit	PainThresholdLimit	PainThresholdRegen	TalentPerkId	ActorId	SkinIndex	HairType	HairColorHex	VoiceBank	Immunity	CreatureClass
+john_hawkwood_boss	20	0.1		140	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 8 16 crit 1.60 critchance 0.05	0.5	0.5	0.03	0.5	1.2	0.3	8	2200	16	2	talent_the_man_who_sold_the_world	human_male	0	hair1	#633D08	player		Human
+francis_reid_daly	20	0.1		130	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 7 14 crit 1.70 critchance 0.05	0.5	0.4	0.04	0.9	1	0.3	8	2000	10	1	talent_weapon_durability	human_male	0			player		Human
+]]
+	local rows = fromCSV(csv, { delimiter = "\t", hasheader = true, hascomments = true })
+	assert(#rows == 2, "Should have 2 data rows")
+
+	assert(rows[1].Id == "john_hawkwood_boss", "First row Id should be 'john_hawkwood_boss'")
+	assert(rows[1].ModifyStartCost == "20", "First row ModifyStartCost should be '20'")
+	assert(rows[2].Id == "francis_reid_daly", "Second row Id should be 'francis_reid_daly'")
+end)
+
+test("full CSV parser complex", function()
+	local original = [[
+#mercenary_profiles																									
+Id	ModifyStartCost	ModifyStep	ModifyLevelLimit	Health	ResistSheet	WoundSlots	MeleeDamage	MeleeAccuracy	RangeAccuracy	ReceiveAmputationChance	ReceiveWoundChanceMult	AttackWoundChanceMult	Dodge	Los	StarvationLimit	PainThresholdLimit	PainThresholdRegen	TalentPerkId	ActorId	SkinIndex	HairType	HairColorHex	VoiceBank	Immunity	CreatureClass
+john_hawkwood_boss	20	0.1		140	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 8 16 crit 1.60 critchance 0.05	0.5	0.5	0.03	0.5	1.2	0.3	8	2200	16	2	talent_the_man_who_sold_the_world	human_male	0	hair1	#633D08	player		Human
+francis_reid_daly	20	0.1		130	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 7 14 crit 1.70 critchance 0.05	0.5	0.4	0.04	0.9	1	0.3	8	2000	10	1	talent_weapon_durability	human_male	0			player		Human
+victoria_boudicca	20	0.1		90	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 5 10 crit 1.70 critchance 0.1	0.4	0.45	0.05	1	1.2	0.3	8	1800	8	1	talent_weapon_distance	human_female	0	hair1	#633D08	player		Human
+persival_fawcett	20	0.1		150	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 6 12 crit 1.70 critchance 0.05	0.5	0.35	0.05	0.6	1	0.25	8	2100	16	1	talent_all_resists	human_male	1	hair1	#633D08	player		Human
+Isabella_capet	20	0.1		100	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 7 14 crit 1.70 critchance 0.15	0.55	0.3	0.03	0.8	1.4	0.35	7	1700	14	2	talent_ignore_infection	human_female	1	hair3	#FF3100	player		Human
+maximilian_rohr	20	0.1		120	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 8 16 crit 1.75 critchance 0.05	0.45	0.45	0.06	0.9	1	0.2	8	2000	14	1	talent_ignore_pain	human_male	0	hair2	#FFC400	player		Human
+priya_marlon	20	0.1		110	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 5 10 crit 1.70 critchance 0.15	0.45	0.35	0.05	1	1.1	0.3	7	2200	12	1	talent_all_consumables_stack	human_female	0	hair2	#FFC400	player		Human
+jacques_kennet	20	0.1		120	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 5 10 crit 1.70 critchance 0.05	0.45	0.35	0.04	0.9	1.2	0.3	8	2300	10	1	talent_reload_time	human_male	0	hair1	#908E87	player		Human
+mirza_aishatu	20	0.1		110	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 7 14 crit 1.70 critchance 0.05	0.55	0.45	0.03	1	1.1	0.25	9	2000	10	1	talent_starving_slower	human_female	1	hair2	#633D08	player		Human
+kenzie_yukio	20	0.1		100	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 5 10 crit 1.70 critchance 0.1	0.6	0.4	0.04	1	1	0.4	7	1600	12	1	talent_weight_dodge_affect	human_male	0	hair2	#633D08	player		Human
+marika_wulfnod	20	0.1		100	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 6 12 crit 1.60 critchance 0.05	0.5	0.5	0.04	1	1	0.3	9	1900	12	1	talent_belt_slots	human_female	0	hair1	#FFC400	player		Human
+auberon_lukas	20	0.1		120	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 4 8 crit 1.60 critchance 0.15	0.45	0.45	0.05	0.8	1	0.2	9	1900	8	2	talent_weapon_slot	human_male	0	hair2	#633D08	player		Human
+niko_medich	20	0.1		120	blunt 0 pierce 0 lacer 0 fire 0 cold 0 poison 0 shock 0 beam 0	HumanHead HumanShoulder HumanArm HumanThigh HumanFeet HumanChest HumanBody HumanStomach HumanKnee	blunt 5 10 crit 1.70 critchance 0.05	0.4	0.45	0.04	1	1.3	0.25	8	2000	10	1	talent_pistol_acc	human_male	0	hair1	#908E87	player		Human
+#end																									
+																									
+#mercenary_classes																									
+Id	ModifyStartCost	ModifyStep	PerkIds																						
+scouts_of_hades	30	0.1	cqc_specialist_basic military_training_basic gear_maintenance_basic blind_fury_basic fire_transfer_basic assault_reflex_basic																						
+ecclipse_blades	30	0.1	berserkgang_basic athletics_basic reaction_training_basic cold_weapon_wielding_basic cannibalism_basic carnage_basic																						
+tifton_elite	30	0.1	heavy_weaponary_basic grenadier_basic selfhealing_basic stationary_defense_basic spray_and_pray_basic shock_awe_basic																						
+tunnel_rats	30	0.1	cautious_basic handmade_shotgun_ammo_basic marauder_basic dirty_shot_basic vicious_symbiosis_basic covermaster_basic																						
+phoenix_brigade	30	0.1	shielding_basic battle_physicist_basic reinforced_battery_basic revealing_flame_basic cauterize_basic scholar_basic																						
+]]
+
+	-- Parse with headers and comments
+	local rows = fromCSV(original, { delimiter = "\t", hasheader = true, hascomments = true })
+	assert(#rows > 0, "Should have parsed rows")
+
+	-- Convert back to CSV with headers
+	local csv = toCSV(rows, { delimiter = "\t", hasheader = true })
+
+	-- Parse again
+	local rows2 = fromCSV(csv, { delimiter = "\t", hasheader = true, hascomments = false })
+
+	-- Verify identical - same number of rows
+	assert(#rows2 == #rows, "Round trip should have same number of rows")
+
+	-- Verify first row data is identical
+	assert(rows2[1].Id == rows[1].Id, "Round trip first row Id should match")
+	assert(
+		rows2[1].ModifyStartCost == rows[1].ModifyStartCost,
+		"Round trip first row ModifyStartCost should match"
+	)
+	assert(rows2[1].Health == rows[1].Health, "Round trip first row Health should match")
+
+	-- Verify headers are preserved
+	assert(rows2.Headers ~= nil, "Round trip rows should have Headers field")
+	assert(#rows2.Headers == #rows.Headers, "Headers should have same number of elements")
+	assert(rows2.Headers[1] == rows.Headers[1], "First header should match")
+end)
+
+-- Test metatable: row[1] and row.foobar return same value
+test("metatable row[1] equals row.header", function()
+	local csv = "Id	Name	Value\n1	Test	100"
+	local rows = fromCSV(csv, { delimiter = "\t", hasheader = true })
+	assert(rows[1][1] == rows[1].Id, "row[1] should equal row.Id")
+	assert(rows[1][2] == rows[1].Name, "row[2] should equal row.Name")
+	assert(rows[1][3] == rows[1].Value, "row[3] should equal row.Value")
+	assert(rows[1].Id == "1", "row.Id should be '1'")
+	assert(rows[1][1] == "1", "row[1] should be '1'")
+end)
+
+-- Test metatable: setting via header name updates numeric index
+test("metatable set via header name", function()
+	local csv = "Id	Name	Value\n1	Test	100"
+	local rows = fromCSV(csv, { delimiter = "\t", hasheader = true })
+	rows[1].Id = "999"
+	assert(rows[1][1] == "999", "Setting row.Id should update row[1]")
+	assert(rows[1].Id == "999", "row.Id should be '999'")
+end)
+
+-- Test metatable: error on unknown header assignment
+test("metatable error on unknown header", function()
+	local csv = "Id	Name	Value\n1	Test	100"
+	local rows = fromCSV(csv, { delimiter = "\t", hasheader = true })
+	local ok, errMsg = pcall(function() rows[1].UnknownHeader = "test" end)
+	assert(ok == false, "Should error on unknown header")
+	assert(string.find(errMsg, "unknown header"), "Error should mention unknown header")
+end)
+
+-- Test metatable: numeric indices still work
+test("metatable numeric indices work", function()
+	local csv = "Id	Name	Value\n1	Test	100"
+	local rows = fromCSV(csv, { delimiter = "\t", hasheader = true })
+	rows[1][1] = "999"
+	assert(rows[1].Id == "999", "Setting row[1] should update row.Id")
+	assert(rows[1][1] == "999", "row[1] should be '999'")
+end)
+
+-- Test metatable: numeric keys work normally
+test("metatable numeric keys work", function()
+	local csv = "Id	Name	Value\n1	Test	100"
+	local rows = fromCSV(csv, { delimiter = "\t", hasheader = true })
+	rows[1][100] = "hundred"
+	assert(rows[1][100] == "hundred", "Numeric keys should work")
+end)
+
+print("\nAll tests completed!")

processor/luahelper.lua

@@ -0,0 +1,352 @@
+-- Custom Lua helpers for math operations
+function min(a, b) return math.min(a, b) end
+
+function max(a, b) return math.max(a, b) end
+
+function round(x, n)
+	if n == nil then n = 0 end
+	return math.floor(x * 10 ^ n + 0.5) / 10 ^ n
+end
+
+function floor(x) return math.floor(x) end
+
+function ceil(x) return math.ceil(x) end
+
+function upper(s) return string.upper(s) end
+
+function lower(s) return string.lower(s) end
+
+function format(s, ...) return string.format(s, ...) end
+
+function trim(s) return string.gsub(s, "^%s*(.-)%s*$", "%1") end
+
+-- String split helper
+function strsplit(inputstr, sep)
+	if sep == nil then sep = "%s" end
+	local t = {}
+	for str in string.gmatch(inputstr, "([^" .. sep .. "]+)") do
+		table.insert(t, str)
+	end
+	return t
+end
+
+---@param table table
+---@param depth number?
+function dump(table, depth)
+	if depth == nil then depth = 0 end
+	if depth > 200 then
+		print("Error: Depth > 200 in dump()")
+		return
+	end
+	for k, v in pairs(table) do
+		if type(v) == "table" then
+			print(string.rep("  ", depth) .. k .. ":")
+			dump(v, depth + 1)
+		else
+			print(string.rep("  ", depth) .. k .. ": ", v)
+		end
+	end
+end
+
+--- @class ParserOptions
+--- @field delimiter string? The field delimiter (default: ",").
+--- @field hasheader boolean? If true, first non-comment row is treated as headers (default: false).
+--- @field hascomments boolean? If true, lines starting with '#' are skipped (default: false).
+
+--- @type ParserOptions
+parserDefaultOptions = { delimiter = ",", hasheader = false, hascomments = false }
+
+--- Validates options against a set of valid option keys.
+--- @param options ParserOptions? The options table to validate
+function areOptionsValid(options)
+	if options == nil then return end
+
+	if type(options) ~= "table" then error("options must be a table") end
+
+	-- Build valid options list from validOptions table
+	local validOptionsStr = ""
+	for k, _ in pairs(parserDefaultOptions) do
+		validOptionsStr = validOptionsStr .. k .. ", "
+	end
+
+	for k, _ in pairs(options) do
+		if parserDefaultOptions[k] == nil then
+			error(
+				"unknown option: " .. tostring(k) .. " (valid options: " .. validOptionsStr .. ")"
+			)
+		end
+	end
+end
+
+--- Parses CSV text into rows and fields using a minimal RFC 4180 state machine.
+---
+--- Requirements/assumptions:
+--- - Input is a single string containing the entire CSV content.
+--- - Field separators are specified by delimiter option (default: comma).
+--- - Newlines between rows may be "\n" or "\r\n". "\r\n" is treated as one line break.
+--- - Fields may be quoted with double quotes (").
+--- - Inside quoted fields, doubled quotes ("") represent a literal quote character.
+--- - No backslash escaping is supported (not part of RFC 4180).
+--- - Newlines inside quoted fields are preserved as part of the field.
+--- - Leading/trailing spaces are preserved; no trimming is performed.
+--- - Empty fields and empty rows are preserved.
+--- - The final row is emitted even if the text does not end with a newline.
+--- - Lines starting with '#' (after optional leading whitespace) are treated as comments and skipped if hascomments is true.
+---
+--- @param csv string The CSV text to parse.
+--- @param options ParserOptions? Options for the parser
+--- @return table #A table (array) of rows; each row is a table with numeric indices and optionally header-named keys.
+function fromCSV(csv, options)
+	if options == nil then options = {} end
+
+	-- Validate options
+	areOptionsValid(options)
+
+	local delimiter = options.delimiter or parserDefaultOptions.delimiter
+	local hasheader = options.hasheader or parserDefaultOptions.hasheader
+	local hascomments = options.hascomments or parserDefaultOptions.hascomments
+
+	local allRows = {}
+	local fields = {}
+	local field = {}
+
+	local STATE_DEFAULT = 1
+	local STATE_IN_QUOTES = 2
+	local STATE_QUOTE_IN_QUOTES = 3
+	local state = STATE_DEFAULT
+
+	local i = 1
+	local len = #csv
+
+	while i <= len do
+		local c = csv:sub(i, i)
+
+		if state == STATE_DEFAULT then
+			if c == '"' then
+				state = STATE_IN_QUOTES
+				i = i + 1
+			elseif c == delimiter then
+				table.insert(fields, table.concat(field))
+				field = {}
+				i = i + 1
+			elseif c == "\r" or c == "\n" then
+				table.insert(fields, table.concat(field))
+				field = {}
+				local shouldAdd = true
+				if hascomments and #fields > 0 then
+					local firstField = fields[1]
+					local trimmed = trim(firstField)
+					if string.sub(trimmed, 1, 1) == "#" then shouldAdd = false end
+				end
+				if shouldAdd then table.insert(allRows, fields) end
+				fields = {}
+				if c == "\r" and i < len and csv:sub(i + 1, i + 1) == "\n" then
+					i = i + 2
+				else
+					i = i + 1
+				end
+			else
+				table.insert(field, c)
+				i = i + 1
+			end
+		elseif state == STATE_IN_QUOTES then
+			if c == '"' then
+				state = STATE_QUOTE_IN_QUOTES
+				i = i + 1
+			else
+				table.insert(field, c)
+				i = i + 1
+			end
+		else -- STATE_QUOTE_IN_QUOTES
+			if c == '"' then
+				table.insert(field, '"')
+				state = STATE_IN_QUOTES
+				i = i + 1
+			elseif c == delimiter then
+				table.insert(fields, table.concat(field))
+				field = {}
+				state = STATE_DEFAULT
+				i = i + 1
+			elseif c == "\r" or c == "\n" then
+				table.insert(fields, table.concat(field))
+				field = {}
+				local shouldAdd = true
+				if hascomments and #fields > 0 then
+					local firstField = fields[1]
+					local trimmed = string.gsub(firstField, "^%s*(.-)%s*$", "%1")
+					if string.sub(trimmed, 1, 1) == "#" then shouldAdd = false end
+				end
+				if shouldAdd then table.insert(allRows, fields) end
+				fields = {}
+				state = STATE_DEFAULT
+				if c == "\r" and i < len and csv:sub(i + 1, i + 1) == "\n" then
+					i = i + 2
+				else
+					i = i + 1
+				end
+			else
+				state = STATE_DEFAULT
+				-- Don't increment i, reprocess character in DEFAULT state
+			end
+		end
+	end
+
+	if #field > 0 or #fields > 0 then
+		table.insert(fields, table.concat(field))
+		local shouldAdd = true
+		if hascomments and #fields > 0 then
+			local firstField = fields[1]
+			local trimmed = string.gsub(firstField, "^%s*(.-)%s*$", "%1")
+			if string.sub(trimmed, 1, 1) == "#" then shouldAdd = false end
+		end
+		if shouldAdd then table.insert(allRows, fields) end
+	end
+
+	if hasheader and #allRows > 0 then
+		local headers = allRows[1]
+		local headerMap = {}
+		for j = 1, #headers do
+			if headers[j] ~= nil and headers[j] ~= "" then
+				local headerName = trim(headers[j])
+				headerMap[headerName] = j
+			end
+		end
+
+		local header_mt = {
+			headers = headerMap,
+			__index = function(t, key)
+				local mt = getmetatable(t)
+				if type(key) == "string" and mt.headers and mt.headers[key] then
+					return rawget(t, mt.headers[key])
+				end
+				return rawget(t, key)
+			end,
+			__newindex = function(t, key, value)
+				local mt = getmetatable(t)
+				if type(key) == "string" and mt.headers then
+					if mt.headers[key] then
+						rawset(t, mt.headers[key], value)
+					else
+						error("unknown header: " .. tostring(key))
+					end
+				else
+					rawset(t, key, value)
+				end
+			end,
+		}
+
+		local rows = {}
+		for ii = 2, #allRows do
+			local row = {}
+			local dataRow = allRows[ii]
+			for j = 1, #dataRow do
+				row[j] = dataRow[j]
+			end
+			setmetatable(row, header_mt)
+			table.insert(rows, row)
+		end
+		rows.Headers = headers
+		return rows
+	end
+
+	return allRows
+end
+
+--- Converts a table of rows back to CSV text format (RFC 4180 compliant).
+---
+--- Requirements:
+--- - Input is a table (array) of rows, where each row is a table (array) of field values.
+--- - Field values are converted to strings using tostring().
+--- - Fields are quoted if they contain the delimiter, newlines, or double quotes.
+--- - Double quotes inside quoted fields are doubled ("").
+--- - Fields are joined with the specified delimiter; rows are joined with newlines.
+--- - If includeHeaders is true and rows have a Headers field, headers are included as the first row.
+---
+--- @param rows table Array of rows, where each row is an array of field values.
+--- @param options ParserOptions? Options for the parser
+--- @return string #CSV-formatted text
+function toCSV(rows, options)
+	if options == nil then options = {} end
+
+	-- Validate options
+	areOptionsValid(options)
+
+	local delimiter = options.delimiter or parserDefaultOptions.delimiter
+	local includeHeaders = options.hasheader or parserDefaultOptions.hasheader
+	local rowStrings = {}
+
+	-- Include headers row if requested and available
+	if includeHeaders and #rows > 0 and rows.Headers ~= nil then
+		local headerStrings = {}
+		for _, header in ipairs(rows.Headers) do
+			local headerStr = tostring(header)
+			local needsQuoting = false
+			if
+				headerStr:find(delimiter)
+				or headerStr:find("\n")
+				or headerStr:find("\r")
+				or headerStr:find('"')
+			then
+				needsQuoting = true
+			end
+			if needsQuoting then
+				headerStr = headerStr:gsub('"', '""')
+				headerStr = '"' .. headerStr .. '"'
+			end
+			table.insert(headerStrings, headerStr)
+		end
+		table.insert(rowStrings, table.concat(headerStrings, delimiter))
+	end
+
+	for _, row in ipairs(rows) do
+		local fieldStrings = {}
+
+		for _, field in ipairs(row) do
+			local fieldStr = tostring(field)
+			local needsQuoting = false
+
+			if
+				fieldStr:find(delimiter)
+				or fieldStr:find("\n")
+				or fieldStr:find("\r")
+				or fieldStr:find('"')
+			then
+				needsQuoting = true
+			end
+
+			if needsQuoting then
+				fieldStr = fieldStr:gsub('"', '""')
+				fieldStr = '"' .. fieldStr .. '"'
+			end
+
+			table.insert(fieldStrings, fieldStr)
+		end
+
+		table.insert(rowStrings, table.concat(fieldStrings, delimiter))
+	end
+
+	return table.concat(rowStrings, "\n")
+end
+
+-- String to number conversion helper
+function num(str) return tonumber(str) or 0 end
+
+-- Number to string conversion
+function str(num) return tostring(num) end
+
+-- Check if string is numeric
+function is_number(str) return tonumber(str) ~= nil end
+
+function isArray(t)
+	if type(t) ~= "table" then return false end
+	local max = 0
+	local count = 0
+	for k, _ in pairs(t) do
+		if type(k) ~= "number" or k < 1 or math.floor(k) ~= k then return false end
+		max = math.max(max, k)
+		count = count + 1
+	end
+	return max == count
+end
+
+modified = false

processor/processor.go

@@ -1,6 +1,7 @@
 package processor
 
 import (
+	_ "embed"
 	"fmt"
 	"io"
 	"net/http"
@@ -13,6 +14,9 @@ import (
 	lua "github.com/yuin/gopher-lua"
 )
 
+//go:embed luahelper.lua
+var helperScript string
+
 // processorLogger is a scoped logger for the processor package.
 var processorLogger = logger.Default.WithPrefix("processor")
 
@@ -160,84 +164,6 @@ func InitLuaHelpers(L *lua.LState) error {
 	initLuaHelpersLogger := processorLogger.WithPrefix("InitLuaHelpers")
 	initLuaHelpersLogger.Debug("Loading Lua helper functions")
 
-	helperScript := `
--- Custom Lua helpers for math operations
-function min(a, b) return math.min(a, b) end
-function max(a, b) return math.max(a, b) end
-function round(x, n)
-	if n == nil then n = 0 end
-	return math.floor(x * 10^n + 0.5) / 10^n
-end
-function floor(x) return math.floor(x) end
-function ceil(x) return math.ceil(x) end
-function upper(s) return string.upper(s) end
-function lower(s) return string.lower(s) end
-function format(s, ...) return string.format(s, ...) end
-function trim(s) return string.gsub(s, "^%s*(.-)%s*$", "%1") end
-
--- String split helper
-function strsplit(inputstr, sep)
-  if sep == nil then
-    sep = "%s"
-  end
-  local t = {}
-  for str in string.gmatch(inputstr, "([^"..sep.."]+)") do
-    table.insert(t, str)
-  end
-  return t
-end
-
----@param table table
----@param depth number?
-function DumpTable(table, depth)
-	if depth == nil then
-		depth = 0
-	end
-	if (depth > 200) then
-		print("Error: Depth > 200 in dumpTable()")
-		return
-	end
-	for k, v in pairs(table) do
-		if (type(v) == "table") then
-			print(string.rep("  ", depth) .. k .. ":")
-			DumpTable(v, depth + 1)
-		else
-			print(string.rep("  ", depth) .. k .. ": ", v)
-		end
-	end
-end
-
--- String to number conversion helper
-function num(str)
-    return tonumber(str) or 0
-end
-
--- Number to string conversion
-function str(num)
-    return tostring(num)
-end
-
--- Check if string is numeric
-function is_number(str)
-    return tonumber(str) ~= nil
-end
-
-function isArray(t)
-    if type(t) ~= "table" then return false end
-    local max = 0
-    local count = 0
-    for k, _ in pairs(t) do
-        if type(k) ~= "number" or k < 1 or math.floor(k) ~= k then
-            return false
-        end
-        max = math.max(max, k)
-        count = count + 1
-    end
-    return max == count
-end
-
-modified = false
-`
 	if err := L.DoString(helperScript); err != nil {
 		initLuaHelpersLogger.Error("Failed to load Lua helper functions: %v", err)
 		return fmt.Errorf("error loading helper functions: %v", err)
@@ -247,6 +173,7 @@ modified = false
 	initLuaHelpersLogger.Debug("Setting up Lua print function to Go")
 	L.SetGlobal("print", L.NewFunction(printToGo))
 	L.SetGlobal("fetch", L.NewFunction(fetch))
+	L.SetGlobal("re", L.NewFunction(EvalRegex))
 	initLuaHelpersLogger.Debug("Lua print and fetch functions bound to Go")
 	return nil
 }
@@ -302,8 +229,8 @@ func BuildLuaScript(luaExpr string) string {
 
 // BuildJSONLuaScript prepares a Lua expression for JSON mode
 func BuildJSONLuaScript(luaExpr string) string {
-	buildJsonLuaScriptLogger := processorLogger.WithPrefix("BuildJSONLuaScript").WithField("inputLuaExpr", luaExpr)
-	buildJsonLuaScriptLogger.Debug("Building full Lua script for JSON mode from expression")
+	buildJSONLuaScriptLogger := processorLogger.WithPrefix("BuildJSONLuaScript").WithField("inputLuaExpr", luaExpr)
+	buildJSONLuaScriptLogger.Debug("Building full Lua script for JSON mode from expression")
 
 	// Perform $var substitutions from globalVariables
 	luaExpr = replaceVariables(luaExpr)
@@ -315,7 +242,7 @@ func BuildJSONLuaScript(luaExpr string) string {
 		local res = run()
 		modified = res == nil or res
 	`, luaExpr)
-	buildJsonLuaScriptLogger.Trace("Generated full JSON Lua script: %q", utils.LimitString(fullScript, 200))
+	buildJSONLuaScriptLogger.Trace("Generated full JSON Lua script: %q", utils.LimitString(fullScript, 200))
 
 	return fullScript
 }
@@ -384,9 +311,9 @@ func fetch(L *lua.LState) int {
 	fetchLogger.Debug("Fetching URL: %q", url)
 
 	// Get options from second argument if provided
-	var method string = "GET"
-	var headers map[string]string = make(map[string]string)
-	var body string = ""
+	var method = "GET"
+	var headers = make(map[string]string)
+	var body = ""
 
 	if L.GetTop() > 1 {
 		options := L.ToTable(2)
@@ -481,3 +408,84 @@ func fetch(L *lua.LState) int {
 	fetchLogger.Debug("Pushed response table to Lua stack")
 	return 1
 }
+
+func EvalRegex(L *lua.LState) int {
+	evalRegexLogger := processorLogger.WithPrefix("evalRegex")
+	evalRegexLogger.Debug("Lua evalRegex function called")
+
+	pattern := L.ToString(1)
+	input := L.ToString(2)
+
+	evalRegexLogger.Debug("Pattern: %q, Input: %q", pattern, input)
+
+	re := regexp.MustCompile(pattern)
+	matches := re.FindStringSubmatch(input)
+
+	evalRegexLogger.Debug("Go regex matches: %v (count: %d)", matches, len(matches))
+	evalRegexLogger.Debug("Matches is nil: %t", matches == nil)
+
+	if len(matches) > 0 {
+		matchesTable := L.NewTable()
+		for i, match := range matches {
+			matchesTable.RawSetInt(i+1, lua.LString(match))
+			evalRegexLogger.Debug("Set table[%d] = %q", i+1, match)
+		}
+		L.Push(matchesTable)
+	} else {
+		L.Push(lua.LNil)
+	}
+
+	evalRegexLogger.Debug("Pushed matches table to Lua stack")
+
+	return 1
+}
+
+// GetLuaFunctionsHelp returns a comprehensive help string for all available Lua functions
+func GetLuaFunctionsHelp() string {
+	return `Lua Functions Available in Global Environment:
+
+MATH FUNCTIONS:
+  min(a, b)   - Returns the minimum of two numbers
+  max(a, b)   - Returns the maximum of two numbers
+  round(x, n) - Rounds x to n decimal places (default 0)
+  floor(x)    - Returns the floor of x
+  ceil(x)     - Returns the ceiling of x
+
+STRING FUNCTIONS:
+  upper(s)                - Converts string to uppercase
+  lower(s)                - Converts string to lowercase
+  format(s, ...)          - Formats string using Lua string.format
+  trim(s)                 - Removes leading/trailing whitespace
+  strsplit(inputstr, sep) - Splits string by separator (default: whitespace)
+  fromCSV(csv, delimiter, hasHeaders) - Parses CSV text into rows of fields (delimiter defaults to ",", hasHeaders defaults to false)
+  toCSV(rows, delimiter)  - Converts table of rows to CSV text format (delimiter defaults to ",")
+  num(str)                - Converts string to number (returns 0 if invalid)
+  str(num)                - Converts number to string
+  is_number(str)          - Returns true if string is numeric
+
+TABLE FUNCTIONS:
+  dump(table, depth) - Prints table structure recursively
+  isArray(t)         - Returns true if table is a sequential array
+
+HTTP FUNCTIONS:
+  fetch(url, options) - Makes HTTP request, returns response table
+    options: {method="GET", headers={}, body=""}
+    returns: {status, statusText, ok, body, headers}
+
+REGEX FUNCTIONS:
+  re(pattern, input)  - Applies regex pattern to input string
+    returns: table with matches (index 0 = full match, 1+ = groups)
+
+UTILITY FUNCTIONS:
+  print(...)          - Prints arguments to Go logger
+
+EXAMPLES:
+  round(3.14159, 2)      -> 3.14
+  strsplit("a,b,c", ",") -> {"a", "b", "c"}
+  upper("hello")         -> "HELLO"
+  min(5, 3)              -> 3
+  num("123")             -> 123
+  is_number("abc")       -> false
+  fetch("https://api.example.com/data")
+  re("(\\w+)@(\\w+)", "user@domain.com") -> {"user@domain.com", "user", "domain.com"}`
+}

processor/processor_test.go

@@ -0,0 +1,147 @@
+package processor_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	lua "github.com/yuin/gopher-lua"
+
+	"cook/processor"
+)
+
+// Happy Path: Function correctly returns all regex capture groups as Lua table when given valid pattern and input.
+func TestEvalRegex_CaptureGroupsReturned(t *testing.T) {
+	L := lua.NewState()
+	defer L.Close()
+	pattern := `(\w+)-(\d+)`
+	input := "test-42"
+	L.Push(lua.LString(pattern))
+	L.Push(lua.LString(input))
+
+	result := processor.EvalRegex(L)
+
+	assert.Equal(t, 1, result, "Expected return value to be 1 (one value pushed to Lua stack)")
+
+	out := L.Get(-1)
+	tbl, ok := out.(*lua.LTable)
+	if !ok {
+		t.Fatalf("Expected Lua table, got %T", out)
+	}
+	expected := []string{"test-42", "test", "42"}
+	for i, v := range expected {
+		val := tbl.RawGetInt(i + 1)
+		assert.Equal(t, lua.LString(v), val, "Expected index %d to be %q", i+1, v)
+	}
+}
+
+// Happy Path: Function returns nil when regex pattern does not match input string.
+func TestEvalRegex_NoMatchReturnsNil(t *testing.T) {
+	L := lua.NewState()
+	defer L.Close()
+	L.Push(lua.LString(`(foo)(bar)`))
+	L.Push(lua.LString("no-match-here"))
+
+	result := processor.EvalRegex(L)
+	assert.Equal(t, 1, result, "Expected return value to be 1 (one value pushed to Lua stack)")
+
+	out := L.Get(-1)
+	// Should be nil when no matches found
+	assert.Equal(t, lua.LNil, out, "Expected nil when no matches found")
+}
+
+// Happy Path: Function handles patterns with no capture groups by returning the full match in the Lua table.
+func TestEvalRegex_NoCaptureGroups(t *testing.T) {
+	L := lua.NewState()
+	defer L.Close()
+	pattern := `foo\d+`
+	input := "foo123"
+	L.Push(lua.LString(pattern))
+	L.Push(lua.LString(input))
+
+	result := processor.EvalRegex(L)
+	assert.Equal(t, 1, result, "Expected return value to be 1 (one value pushed to Lua stack)")
+
+	out := L.Get(-1)
+	tbl, ok := out.(*lua.LTable)
+	if !ok {
+		t.Fatalf("Expected Lua table, got %T", out)
+	}
+	fullMatch := tbl.RawGetInt(1)
+	assert.Equal(t, lua.LString("foo123"), fullMatch)
+	// There should be only the full match (index 1)
+	count := 0
+	tbl.ForEach(func(k, v lua.LValue) {
+		count++
+	})
+	assert.Equal(t, 1, count)
+}
+
+// Edge Case: Function handles invalid regex pattern by letting regexp.MustCompile panic (which is expected behavior)
+func TestEvalRegex_InvalidPattern(t *testing.T) {
+	L := lua.NewState()
+	defer L.Close()
+	pattern := `([a-z` // invalid regex
+	L.Push(lua.LString(pattern))
+	L.Push(lua.LString("someinput"))
+
+	// This should panic due to invalid regex pattern
+	assert.Panics(t, func() {
+		processor.EvalRegex(L)
+	}, "Expected panic for invalid regex pattern")
+}
+
+// Edge Case: Function returns nil when input string is empty and pattern doesn't match.
+func TestEvalRegex_EmptyInputString(t *testing.T) {
+	L := lua.NewState()
+	defer L.Close()
+	L.Push(lua.LString(`(foo)`))
+	L.Push(lua.LString(""))
+
+	result := processor.EvalRegex(L)
+	assert.Equal(t, 1, result, "Expected return value to be 1 (one value pushed to Lua stack)")
+
+	out := L.Get(-1)
+	// Should be nil when no matches found
+	assert.Equal(t, lua.LNil, out, "Expected nil when input is empty and pattern doesn't match")
+}
+
+// Edge Case: Function handles nil or missing arguments gracefully without causing a runtime panic.
+func TestEvalRegex_MissingArguments(t *testing.T) {
+	L := lua.NewState()
+	defer L.Close()
+	defer func() {
+		if r := recover(); r != nil {
+			t.Errorf("Did not expect panic when arguments are missing, got: %v", r)
+		}
+	}()
+	// No arguments pushed at all
+	processor.EvalRegex(L)
+	// Should just not match anything or produce empty table, but must not panic
+}
+
+func TestEvalComplexRegex(t *testing.T) {
+	// Test complex regex pattern with multiple capture groups
+	L := lua.NewState()
+	defer L.Close()
+	pattern := `^((Bulk_)?(Pistol|Rifle).*?Round.*?)$`
+	input := "Pistol_Round"
+	L.Push(lua.LString(pattern))
+	L.Push(lua.LString(input))
+
+	processor.EvalRegex(L)
+
+	out := L.Get(-1)
+	tbl, ok := out.(*lua.LTable)
+	if !ok {
+		t.Fatalf("Expected Lua table, got %T", out)
+	}
+
+	// Pattern should match: ["Pistol_Round", "Pistol_Round", "", "Pistol"]
+	// This creates 4 elements in the matches array, not 1
+	expectedCount := 4
+	actualCount := 0
+	tbl.ForEach(func(k, v lua.LValue) {
+		actualCount++
+	})
+	assert.Equal(t, expectedCount, actualCount, "Expected %d matches for pattern %q with input %q", expectedCount, pattern, input)
+}

processor/regex.go

@@ -22,9 +22,9 @@ type CaptureGroup struct {
 	Range   [2]int
 }
 
-// ProcessContent applies regex replacement with Lua processing
-// The filename here exists ONLY so we can pass it to the lua environment
-// It's not used for anything else
+// ProcessRegex applies regex replacement with Lua processing.
+// The filename here exists ONLY so we can pass it to the lua environment.
+// It's not used for anything else.
 func ProcessRegex(content string, command utils.ModifyCommand, filename string) ([]utils.ReplaceCommand, error) {
 	processRegexLogger := regexLogger.WithPrefix("ProcessRegex").WithField("commandName", command.Name).WithField("file", filename)
 	processRegexLogger.Debug("Starting regex processing for file")
@@ -53,7 +53,7 @@ func ProcessRegex(content string, command utils.ModifyCommand, filename string)
 		processRegexLogger.Error("Error compiling pattern %q: %v", pattern, err)
 		return commands, fmt.Errorf("error compiling pattern: %v", err)
 	}
-	processRegexLogger.Debug("Compiled pattern successfully in %v", time.Since(patternCompileStart))
+	processRegexLogger.Debug("Compiled pattern successfully in %v. Pattern: %s", time.Since(patternCompileStart), pattern)
 
 	// Same here, it's just string concatenation, it won't kill us
 	// More important is that we don't fuck up the command
@@ -77,7 +77,7 @@ func ProcessRegex(content string, command utils.ModifyCommand, filename string)
 	processRegexLogger.Debug("Pattern complexity estimate: %d", patternComplexity)
 
 	if len(indices) == 0 {
-		processRegexLogger.Warning("No matches found for regex: %q", pattern)
+		processRegexLogger.Warning("No matches found for regex: %s", pattern)
 		processRegexLogger.Debug("Total regex processing time: %v", time.Since(startTime))
 		return commands, nil
 	}
@@ -216,9 +216,6 @@ func ProcessRegex(content string, command utils.ModifyCommand, filename string)
 		}
 
 		if replacement == "" {
-			// Apply the modifications to the original match
-			replacement = matchContent
-
 			// Count groups that were actually modified
 			modifiedGroupsCount := 0
 			for _, capture := range updatedCaptureGroups {
@@ -335,6 +332,9 @@ func resolveRegexPlaceholders(pattern string) string {
 	pattern = strings.ReplaceAll(pattern, "!any", `.*?`)
 	resolveLogger.Debug("Replaced !any with non-greedy wildcard")
 
+	pattern = strings.ReplaceAll(pattern, "\n", "\r?\n")
+	resolveLogger.Debug("Added optional carriage return support for Windows line endings")
+
 	repPattern := regexp.MustCompile(`!rep\(([^,]+),\s*(\d+)\)`)
 	// !rep(pattern, count) repeats the pattern n times
 	// Inserting !any between each repetition

processor/regex_test.go

@@ -30,7 +30,7 @@ func normalizeWhitespace(s string) string {
 	return re.ReplaceAllString(strings.TrimSpace(s), " ")
 }
 
-func ApiAdaptor(content string, regex string, lua string) (string, int, int, error) {
+func APIAdaptor(content string, regex string, lua string) (string, int, int, error) {
 	command := utils.ModifyCommand{
 		Regex:    regex,
 		Lua:      lua,
@@ -79,7 +79,7 @@ func TestSimpleValueMultiplication(t *testing.T) {
     </item>
 </config>`
 
-	result, mods, matches, err := ApiAdaptor(content, `(?s)<value>(\d+)</value>`, "v1 = v1*1.5")
+	result, mods, matches, err := APIAdaptor(content, `(?s)<value>(\d+)</value>`, "v1 = v1*1.5")
 
 	assert.NoError(t, err, "Error processing content: %v", err)
 	assert.Equal(t, 1, matches, "Expected 1 match, got %d", matches)
@@ -100,7 +100,7 @@ func TestShorthandNotation(t *testing.T) {
     </item>
 </config>`
 
-	result, mods, matches, err := ApiAdaptor(content, `(?s)<value>(\d+)</value>`, "v1*1.5")
+	result, mods, matches, err := APIAdaptor(content, `(?s)<value>(\d+)</value>`, "v1*1.5")
 
 	assert.NoError(t, err, "Error processing content: %v", err)
 	assert.Equal(t, 1, matches, "Expected 1 match, got %d", matches)
@@ -121,7 +121,7 @@ func TestShorthandNotationFloats(t *testing.T) {
     </item>
 </config>`
 
-	result, mods, matches, err := ApiAdaptor(content, `(?s)<value>(\d+\.\d+)</value>`, "v1*1.5")
+	result, mods, matches, err := APIAdaptor(content, `(?s)<value>(\d+\.\d+)</value>`, "v1*1.5")
 
 	assert.NoError(t, err, "Error processing content: %v", err)
 	assert.Equal(t, 1, matches, "Expected 1 match, got %d", matches)
@@ -146,7 +146,7 @@ func TestArrayNotation(t *testing.T) {
     </prices>
 </config>`
 
-	result, mods, matches, err := ApiAdaptor(content, `(?s)<price>(\d+)</price>`, "v1*2")
+	result, mods, matches, err := APIAdaptor(content, `(?s)<price>(\d+)</price>`, "v1*2")
 
 	assert.NoError(t, err, "Error processing content: %v", err)
 	assert.Equal(t, 3, matches, "Expected 3 matches, got %d", matches)
@@ -167,7 +167,7 @@ func TestMultipleNumericMatches(t *testing.T) {
     <entry>400</entry>
 </data>`
 
-	result, mods, matches, err := ApiAdaptor(content, `<entry>(\d+)</entry>`, "v1*2")
+	result, mods, matches, err := APIAdaptor(content, `<entry>(\d+)</entry>`, "v1*2")
 
 	assert.NoError(t, err, "Error processing content: %v", err)
 	assert.Equal(t, 3, matches, "Expected 3 matches, got %d", matches)
@@ -186,7 +186,7 @@ func TestMultipleStringMatches(t *testing.T) {
     <name>Mary_modified</name>
 </data>`
 
-	result, mods, matches, err := ApiAdaptor(content, `<name>([A-Za-z]+)</name>`, `s1 = s1 .. "_modified"`)
+	result, mods, matches, err := APIAdaptor(content, `<name>([A-Za-z]+)</name>`, `s1 = s1 .. "_modified"`)
 
 	assert.NoError(t, err, "Error processing content: %v", err)
 	assert.Equal(t, 2, matches, "Expected 2 matches, got %d", matches)
@@ -205,7 +205,7 @@ func TestStringUpperCase(t *testing.T) {
     <user>MARY</user>
 </users>`
 
-	result, mods, matches, err := ApiAdaptor(content, `<user>([A-Za-z]+)</user>`, `s1 = string.upper(s1)`)
+	result, mods, matches, err := APIAdaptor(content, `<user>([A-Za-z]+)</user>`, `s1 = string.upper(s1)`)
 
 	assert.NoError(t, err, "Error processing content: %v", err)
 	assert.Equal(t, 2, matches, "Expected 2 matches, got %d", matches)
@@ -224,7 +224,7 @@ func TestStringConcatenation(t *testing.T) {
     <product>Banana_fruit</product>
 </products>`
 
-	result, mods, matches, err := ApiAdaptor(content, `<product>([A-Za-z]+)</product>`, `s1 = s1 .. "_fruit"`)
+	result, mods, matches, err := APIAdaptor(content, `<product>([A-Za-z]+)</product>`, `s1 = s1 .. "_fruit"`)
 
 	assert.NoError(t, err, "Error processing content: %v", err)
 	assert.Equal(t, 2, matches, "Expected 2 matches, got %d", matches)
@@ -254,7 +254,7 @@ func TestDecimalValues(t *testing.T) {
 	regex := regexp.MustCompile(`(?s)<value>([0-9.]+)</value>.*?<multiplier>([0-9.]+)</multiplier>`)
 	luaExpr := BuildLuaScript("v1 = v1 * v2")
 
-	result, _, _, err := ApiAdaptor(content, regex.String(), luaExpr)
+	result, _, _, err := APIAdaptor(content, regex.String(), luaExpr)
 	assert.NoError(t, err, "Error processing content: %v", err)
 
 	normalizedModified := normalizeWhitespace(result)
@@ -282,7 +282,7 @@ func TestLuaMathFunctions(t *testing.T) {
 	regex := regexp.MustCompile(`(?s)<value>(\d+)</value>`)
 	luaExpr := BuildLuaScript("v1 = math.sqrt(v1)")
 
-	modifiedContent, _, _, err := ApiAdaptor(content, regex.String(), luaExpr)
+	modifiedContent, _, _, err := APIAdaptor(content, regex.String(), luaExpr)
 	assert.NoError(t, err, "Error processing content: %v", err)
 
 	normalizedModified := normalizeWhitespace(modifiedContent)
@@ -310,7 +310,7 @@ func TestDirectAssignment(t *testing.T) {
 	regex := regexp.MustCompile(`(?s)<value>(\d+)</value>`)
 	luaExpr := BuildLuaScript("=0")
 
-	modifiedContent, _, _, err := ApiAdaptor(content, regex.String(), luaExpr)
+	modifiedContent, _, _, err := APIAdaptor(content, regex.String(), luaExpr)
 	assert.NoError(t, err, "Error processing content: %v", err)
 
 	normalizedModified := normalizeWhitespace(modifiedContent)
@@ -369,7 +369,7 @@ func TestStringAndNumericOperations(t *testing.T) {
 			luaExpr := BuildLuaScript(tt.luaExpression)
 
 			// Process with our function
-			result, modCount, _, err := ApiAdaptor(tt.input, pattern, luaExpr)
+			result, modCount, _, err := APIAdaptor(tt.input, pattern, luaExpr)
 			assert.NoError(t, err, "Process function failed: %v", err)
 
 			// Check results
@@ -430,7 +430,7 @@ func TestEdgeCases(t *testing.T) {
 			luaExpr := BuildLuaScript(tt.luaExpression)
 
 			// Process with our function
-			result, modCount, _, err := ApiAdaptor(tt.input, pattern, luaExpr)
+			result, modCount, _, err := APIAdaptor(tt.input, pattern, luaExpr)
 			assert.NoError(t, err, "Process function failed: %v", err)
 
 			// Check results
@@ -453,7 +453,7 @@ func TestNamedCaptureGroups(t *testing.T) {
     </item>
 </config>`
 
-	result, mods, matches, err := ApiAdaptor(content, `(?s)<value>(?<amount>\d+)</value>`, "amount = amount * 2")
+	result, mods, matches, err := APIAdaptor(content, `(?s)<value>(?<amount>\d+)</value>`, "amount = amount * 2")
 
 	assert.NoError(t, err, "Error processing content: %v", err)
 	assert.Equal(t, 1, matches, "Expected 1 match, got %d", matches)
@@ -474,7 +474,7 @@ func TestNamedCaptureGroupsNum(t *testing.T) {
     </item>
 </config>`
 
-	result, mods, matches, err := ApiAdaptor(content, `(?s)<value>(?<amount>!num)</value>`, "amount = amount * 2")
+	result, mods, matches, err := APIAdaptor(content, `(?s)<value>(?<amount>!num)</value>`, "amount = amount * 2")
 
 	assert.NoError(t, err, "Error processing content: %v", err)
 	assert.Equal(t, 1, matches, "Expected 1 match, got %d", matches)
@@ -495,7 +495,7 @@ func TestMultipleNamedCaptureGroups(t *testing.T) {
     <quantity>15</quantity>
 </product>`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`(?s)<name>(?<prodName>[^<]+)</name>.*?<price>(?<prodPrice>\d+\.\d+)</price>.*?<quantity>(?<prodQty>\d+)</quantity>`,
 		`prodName = string.upper(prodName)
 		 prodPrice = round(prodPrice + 8, 2)
@@ -518,7 +518,7 @@ func TestMixedIndexedAndNamedCaptures(t *testing.T) {
     <data>VALUE</data>
 </entry>`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`(?s)<id>(\d+)</id>.*?<data>(?<dataField>[^<]+)</data>`,
 		`v1 = v1 * 2
 		 dataField = string.upper(dataField)`)
@@ -550,7 +550,7 @@ func TestComplexNestedNamedCaptures(t *testing.T) {
 		</contact>
 	</person>`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`(?s)<details>.*?<name>(?<fullName>[^<]+)</name>.*?<age>(?<age>\d+)</age>`,
 		`fullName = string.upper(fullName) .. " (" .. age .. ")"`)
 
@@ -571,7 +571,7 @@ func TestNamedCaptureWithVariableReadback(t *testing.T) {
     <mana>300</mana>
 </stats>`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`(?s)<health>(?<hp>\d+)</health>.*?<mana>(?<mp>\d+)</mana>`,
 		`hp = hp * 1.5
 		 mp = mp * 1.5`)
@@ -587,7 +587,7 @@ func TestNamedCaptureWithSpecialCharsInName(t *testing.T) {
 
 	expected := `<data value="84" min="10" max="100" />`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`<data value="(?<val_1>\d+)"`,
 		`val_1 = val_1 * 2`)
 
@@ -602,7 +602,7 @@ func TestEmptyNamedCapture(t *testing.T) {
 
 	expected := `<tag attr="default" />`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`attr="(?<value>.*?)"`,
 		`value = value == "" and "default" or value`)
 
@@ -617,7 +617,7 @@ func TestMultipleNamedCapturesInSameLine(t *testing.T) {
 
 	expected := `<rect x="20" y="40" width="200" height="100" />`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`x="(?<x>\d+)" y="(?<y>\d+)" width="(?<w>\d+)" height="(?<h>\d+)"`,
 		`x = x * 2
 		 y = y * 2
@@ -641,7 +641,7 @@ func TestConditionalNamedCapture(t *testing.T) {
 	<item status="inactive" count="10" />
 	`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`<item status="(?<status>[^"]+)" count="(?<count>\d+)"`,
 		`count = status == "active" and count * 2 or count`)
 
@@ -662,7 +662,7 @@ func TestLuaFunctionsOnNamedCaptures(t *testing.T) {
 	<user name="JANE SMITH" role="admin" />
 	`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`<user name="(?<name>[^"]+)" role="(?<role>[^"]+)"`,
 		`-- Capitalize first letters for regular users
 		 if role == "user" then
@@ -692,7 +692,7 @@ func TestNamedCaptureWithMath(t *testing.T) {
 	<item price="19.99" quantity="3" total="59.97" />
 	`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`<item price="(?<price>\d+\.\d+)" quantity="(?<qty>\d+)"!any$`,
 		`-- Calculate and add total
 		 replacement = string.format('<item price="%s" quantity="%s" total="%.2f" />',
@@ -712,7 +712,7 @@ func TestNamedCaptureWithGlobals(t *testing.T) {
 
 	expected := `<temp unit="F">77</temp>`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`<temp unit="(?<unit>[CF]?)">(?<value>\d+)</temp>`,
 		`if unit == "C" then
 		  value = value * 9/5 + 32
@@ -739,7 +739,7 @@ func TestMixedDynamicAndNamedCaptures(t *testing.T) {
 	<color rgb="0,255,0" name="GREEN" hex="#00FF00" />
 	`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`<color rgb="(?<r>\d+),(?<g>\d+),(?<b>\d+)" name="(?<colorName>[^"]+)" />`,
 		`-- Uppercase the name
 		 colorName = string.upper(colorName)
@@ -765,7 +765,7 @@ func TestNamedCapturesWithMultipleReferences(t *testing.T) {
 
 	expected := `<text format="uppercase" length="11">HELLO WORLD</text>`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`<text>(?<content>[^<]+)</text>`,
 		`local uppercaseContent = string.upper(content)
 		 local contentLength = string.len(content)
@@ -783,7 +783,7 @@ func TestNamedCaptureWithJsonData(t *testing.T) {
 
 	expected := `<data>{"name":"JOHN","age":30}</data>`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`<data>(?<json>\{.*?\})</data>`,
 		`-- Parse JSON (simplified, assumes valid JSON)
 		 local name = json:match('"name":"([^"]+)"')
@@ -813,7 +813,7 @@ func TestNamedCaptureInXML(t *testing.T) {
 	</product>
 	`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`(?s)<price currency="(?<currency>[^"]+)">(?<price>\d+\.\d+)</price>.*?<stock>(?<stock>\d+)</stock>`,
 		`-- Add 20% to price if USD
 		 if currency == "USD" then
@@ -870,7 +870,7 @@ func TestComprehensiveNamedCaptures(t *testing.T) {
 	</products>
 	`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`(?s)<product sku="(?<sku>[^"]+)" status="(?<status>[^"]+)"[^>]*>\s*<name>(?<product_name>[^<]+)</name>\s*<price currency="(?<currency>[^"]+)">(?<price>\d+\.\d+)</price>\s*<quantity>(?<qty>\d+)</quantity>`,
 		`-- Only process in-stock items
 		if status == "in-stock" then
@@ -924,7 +924,7 @@ func TestVariousNamedCaptureFormats(t *testing.T) {
 	</data>
 	`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`<entry id="(?<id_num>\d+)" value="(?<val>\d+)"(?: status="(?<status>[^"]*)")? />`,
 		`-- Prefix the ID with "ID-"
 		id_num = "ID-" .. id_num
@@ -963,7 +963,7 @@ func TestSimpleNamedCapture(t *testing.T) {
 
 	expected := `<product name="WIDGET" price="19.99"/>`
 
-	result, mods, matches, err := ApiAdaptor(content,
+	result, mods, matches, err := APIAdaptor(content,
 		`name="(?<product_name>[^"]+)"`,
 		`product_name = string.upper(product_name)`)
 

processor/surgical_json_test.go

@@ -0,0 +1,847 @@
+package processor
+
+import (
+	"cook/utils"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func TestSurgicalJSONEditing(t *testing.T) {
+	tests := []struct {
+		name     string
+		content  string
+		luaCode  string
+		expected string
+	}{
+		{
+			name: "Modify single field",
+			content: `{
+  "name": "test",
+  "value": 42,
+  "description": "original"
+}`,
+			luaCode: `
+data.value = 84
+modified = true
+`,
+			expected: `{
+  "name": "test",
+  "value": 84,
+  "description": "original"
+}`,
+		},
+		{
+			name: "Add new field",
+			content: `{
+  "name": "test",
+  "value": 42
+}`,
+			luaCode: `
+data.newField = "added"
+modified = true
+`,
+			expected: `{
+  "name": "test",
+  "value": 42
+,"newField": "added"}`, // sjson.Set() adds new fields in compact format
+		},
+		{
+			name: "Modify nested field",
+			content: `{
+  "config": {
+    "settings": {
+      "enabled": false,
+      "timeout": 30
+    }
+  }
+}`,
+			luaCode: `
+data.config.settings.enabled = true
+data.config.settings.timeout = 60
+modified = true
+`,
+			expected: `{
+  "config": {
+    "settings": {
+      "enabled": true,
+      "timeout": 60
+    }
+  }
+}`,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			command := utils.ModifyCommand{
+				Name: "test",
+				Lua:  tt.luaCode,
+			}
+
+			commands, err := ProcessJSON(tt.content, command, "test.json")
+			if err != nil {
+				t.Fatalf("ProcessJSON failed: %v", err)
+			}
+
+			if len(commands) == 0 {
+				t.Fatal("Expected at least one command")
+			}
+
+			// Apply the commands
+			result := tt.content
+			for _, cmd := range commands {
+				result = result[:cmd.From] + cmd.With + result[cmd.To:]
+			}
+
+			diff := cmp.Diff(result, tt.expected)
+			if diff != "" {
+				t.Errorf("Differences:\n%s", diff)
+			}
+
+			// Check the actual result matches expected
+			if result != tt.expected {
+				t.Errorf("Expected:\n%s\n\nGot:\n%s", tt.expected, result)
+			}
+		})
+	}
+}
+
+func TestSurgicalJSONPreservesFormatting(t *testing.T) {
+	// Test that surgical editing preserves the original formatting structure
+	content := `{
+  "Defaults": {
+    "Behaviour": "None",
+    "Description": "",
+    "DisplayName": "",
+    "FlavorText": "",
+    "Icon": "None",
+    "MaxStack": 1,
+    "Override_Glow_Icon": "None",
+    "Weight": 0,
+    "bAllowZeroWeight": false
+  },
+  "RowStruct": "/Script/Icarus.ItemableData",
+  "Rows": [
+    {
+      "Description": "NSLOCTEXT(\"D_Itemable\", \"Item_Fiber-Description\", \"A bundle of soft fiber, highly useful.\")",
+      "DisplayName": "NSLOCTEXT(\"D_Itemable\", \"Item_Fiber-DisplayName\", \"Fiber\")",
+      "FlavorText": "NSLOCTEXT(\"D_Itemable\", \"Item_Fiber-FlavorText\", \"Fiber is collected from bast, the strong inner bark of certain flowering plants.\")",
+      "Icon": "/Game/Assets/2DArt/UI/Items/Item_Icons/Resources/ITEM_Fibre.ITEM_Fibre",
+      "MaxStack": 1000000,
+      "Name": "Item_Fiber",
+      "Weight": 10
+    }
+  ]
+}`
+
+	expected := `{
+  "Defaults": {
+    "Behaviour": "None",
+    "Description": "",
+    "DisplayName": "",
+    "FlavorText": "",
+    "Icon": "None",
+    "MaxStack": 1,
+    "Override_Glow_Icon": "None",
+    "Weight": 0,
+    "bAllowZeroWeight": false
+  },
+  "RowStruct": "/Script/Icarus.ItemableData",
+  "Rows": [
+    {
+      "Description": "NSLOCTEXT(\"D_Itemable\", \"Item_Fiber-Description\", \"A bundle of soft fiber, highly useful.\")",
+      "DisplayName": "NSLOCTEXT(\"D_Itemable\", \"Item_Fiber-DisplayName\", \"Fiber\")",
+      "FlavorText": "NSLOCTEXT(\"D_Itemable\", \"Item_Fiber-FlavorText\", \"Fiber is collected from bast, the strong inner bark of certain flowering plants.\")",
+      "Icon": "/Game/Assets/2DArt/UI/Items/Item_Icons/Resources/ITEM_Fibre.ITEM_Fibre",
+      "MaxStack": 1000000,
+      "Name": "Item_Fiber",
+      "Weight": 500
+    }
+  ]
+}`
+
+	command := utils.ModifyCommand{
+		Name: "test",
+		Lua: `
+-- Modify the weight of the first item
+data.Rows[1].Weight = 500
+modified = true
+`,
+	}
+
+	commands, err := ProcessJSON(content, command, "test.json")
+	if err != nil {
+		t.Fatalf("ProcessJSON failed: %v", err)
+	}
+
+	if len(commands) == 0 {
+		t.Fatal("Expected at least one command")
+	}
+
+	// Apply the commands
+	result := content
+	for _, cmd := range commands {
+		result = result[:cmd.From] + cmd.With + result[cmd.To:]
+	}
+
+	diff := cmp.Diff(result, expected)
+	if diff != "" {
+		t.Errorf("Differences:\n%s", diff)
+	}
+
+	// Check that the result matches expected (preserves formatting and changes weight)
+	if result != expected {
+		t.Errorf("Expected:\n%s\n\nGot:\n%s", expected, result)
+	}
+}
+
+func TestSurgicalJSONPreservesFormatting2(t *testing.T) {
+	// Test that surgical editing preserves the original formatting structure
+	content := `
+{
+  "RowStruct": "/Script/Icarus.ProcessorRecipe",
+  "Defaults": {
+    "bForceDisableRecipe": false,
+    "Requirement": {
+      "RowName": "None",
+      "DataTableName": "D_Talents"
+    },
+    "SessionRequirement": {
+      "RowName": "None",
+      "DataTableName": "D_CharacterFlags"
+    },
+    "CharacterRequirement": {
+      "RowName": "None",
+      "DataTableName": "D_CharacterFlags"
+    },
+    "RequiredMillijoules": 2500,
+    "RecipeSets": [],
+    "ResourceCostMultipliers": [],
+    "Inputs": [
+      {
+        "Element": {
+          "RowName": "None",
+          "DataTableName": "D_ItemsStatic"
+        },
+        "Count": 1,
+        "DynamicProperties": []
+      }
+    ],
+    "Container": {
+      "Value": "None"
+    },
+    "ResourceInputs": [],
+    "bSelectOutputItemRandomly": false,
+    "bContainsContainer": false,
+    "ItemIconOverride": {
+      "ItemStaticData": {
+        "RowName": "None",
+        "DataTableName": "D_ItemsStatic"
+      },
+      "ItemDynamicData": [],
+      "ItemCustomStats": [],
+      "CustomProperties": {
+        "StaticWorldStats": [],
+        "StaticWorldHeldStats": [],
+        "Stats": [],
+        "Alterations": [],
+        "LivingItemSlots": []
+      },
+      "DatabaseGUID": "",
+      "ItemOwnerLookupId": -1,
+      "RuntimeTags": {
+        "GameplayTags": []
+      }
+    },
+    "Outputs": [
+      {
+        "Element": {
+          "RowName": "None",
+          "DataTableName": "D_ItemTemplate"
+        },
+        "Count": 1,
+        "DynamicProperties": []
+      }
+    ],
+    "ResourceOutputs": [],
+    "Refundable": "Inherit",
+    "ExperienceMultiplier": 1,
+    "Audio": {
+      "RowName": "None",
+      "DataTableName": "D_CraftingAudioData"
+    }
+  },
+  "Rows": [
+    {
+      "Name": "Biofuel1",
+      "RecipeSets": [
+        {
+          "RowName": "Composter",
+          "DataTableName": "D_RecipeSets"
+        }
+      ],
+      "Inputs": [
+        {
+          "Element": {
+            "RowName": "Raw_Meat",
+            "DataTableName": "D_ItemsStatic"
+          },
+          "Count": 2,
+          "DynamicProperties": []
+        },
+        {
+          "Element": {
+            "RowName": "Tree_Sap",
+            "DataTableName": "D_ItemsStatic"
+          },
+          "Count": 1,
+          "DynamicProperties": []
+        }
+      ],
+      "Outputs": [],
+      "Audio": {
+        "RowName": "Composter"
+      },
+      "ResourceOutputs": [
+        {
+          "Type": {
+            "Value": "Biofuel"
+          },
+          "RequiredUnits": 100
+        }
+      ]
+    }
+  ]
+}
+  `
+
+	expected := `
+{
+  "RowStruct": "/Script/Icarus.ProcessorRecipe",
+  "Defaults": {
+    "bForceDisableRecipe": false,
+    "Requirement": {
+      "RowName": "None",
+      "DataTableName": "D_Talents"
+    },
+    "SessionRequirement": {
+      "RowName": "None",
+      "DataTableName": "D_CharacterFlags"
+    },
+    "CharacterRequirement": {
+      "RowName": "None",
+      "DataTableName": "D_CharacterFlags"
+    },
+    "RequiredMillijoules": 2500,
+    "RecipeSets": [],
+    "ResourceCostMultipliers": [],
+    "Inputs": [
+      {
+        "Element": {
+          "RowName": "None",
+          "DataTableName": "D_ItemsStatic"
+        },
+        "Count": 1,
+        "DynamicProperties": []
+      }
+    ],
+    "Container": {
+      "Value": "None"
+    },
+    "ResourceInputs": [],
+    "bSelectOutputItemRandomly": false,
+    "bContainsContainer": false,
+    "ItemIconOverride": {
+      "ItemStaticData": {
+        "RowName": "None",
+        "DataTableName": "D_ItemsStatic"
+      },
+      "ItemDynamicData": [],
+      "ItemCustomStats": [],
+      "CustomProperties": {
+        "StaticWorldStats": [],
+        "StaticWorldHeldStats": [],
+        "Stats": [],
+        "Alterations": [],
+        "LivingItemSlots": []
+      },
+      "DatabaseGUID": "",
+      "ItemOwnerLookupId": -1,
+      "RuntimeTags": {
+        "GameplayTags": []
+      }
+    },
+    "Outputs": [
+      {
+        "Element": {
+          "RowName": "None",
+          "DataTableName": "D_ItemTemplate"
+        },
+        "Count": 1,
+        "DynamicProperties": []
+      }
+    ],
+    "ResourceOutputs": [],
+    "Refundable": "Inherit",
+    "ExperienceMultiplier": 1,
+    "Audio": {
+      "RowName": "None",
+      "DataTableName": "D_CraftingAudioData"
+    }
+  },
+  "Rows": [
+    {
+      "Name": "Biofuel1",
+      "RecipeSets": [
+        {
+          "RowName": "Composter",
+          "DataTableName": "D_RecipeSets"
+        }
+      ],
+      "Inputs": [
+        {
+          "Element": {
+            "RowName": "Raw_Meat",
+            "DataTableName": "D_ItemsStatic"
+          },
+          "Count": 2,
+          "DynamicProperties": []
+        }
+      ],
+      "Outputs": [],
+      "Audio": {
+        "RowName": "Composter"
+      },
+      "ResourceOutputs": [
+        {
+          "Type": {
+            "Value": "Biofuel"
+          },
+          "RequiredUnits": 100
+        }
+      ]
+    }
+  ]
+}
+  `
+
+	command := utils.ModifyCommand{
+		Name: "test",
+		Lua: `
+    -- Define regex patterns for matching recipe names
+    local function matchesPattern(name, pattern)
+      local matches = re(pattern, name)
+      -- Check if matches table has any content (index 0 or 1 should exist if there's a match)
+      return matches and (matches[0] or matches[1])
+    end
+
+    -- Selection pattern for recipes that get multiplied
+    local selectionPattern = "(?-s)(Bulk_)?(Pistol|Rifle).*?Round.*?|(Carbon|Composite)_Paste.*|(Gold|Copper)_Wire|(Ironw|Copper)_Nail|(Platinum|Steel|Cold_Steel|Titanium)_Ingot|.*?Shotgun_Shell.*?|.*_Arrow|.*_Bolt|.*_Fertilizer_?\\d*|.*_Grenade|.*_Pill|.*_Tonic|Aluminum|Ammo_Casing|Animal_Fat|Carbon_Fiber|Composites|Concrete_Mix|Cured_Leather_?\\d?|Electronics|Epoxy_?\\d?|Glass\\d?|Gunpowder\\w*|Health_.*|Titanium_Plate|Organic_Resin|Platinum_Sheath|Refined_[a-zA-Z]+|Rope|Shotgun_Casing|Steel_Bloom\\d?|Tree_Sap\\w*"
+
+    -- Ingot pattern for recipes that get count set to 1
+    local ingotPattern = "(?-s)(Platinum|Steel|Cold_Steel|Titanium)_Ingot|Aluminum|Refined_[a-zA-Z]+|Glass\\d?"
+
+    local factor = 16
+    local bonus = 0.5
+
+    for _, row in ipairs(data.Rows) do
+      local recipeName = row.Name
+
+      -- Special case: Biofuel recipes - remove Tree_Sap input
+      if string.find(recipeName, "Biofuel") then
+        if row.Inputs then
+          for i = #row.Inputs, 1, -1 do
+            local input = row.Inputs[i]
+            if input.Element and input.Element.RowName and string.find(input.Element.RowName, "Tree_Sap") then
+              table.remove(row.Inputs, i)
+              print("Removing input 'Tree_Sap' from processor recipe '" .. recipeName .. "'")
+            end
+          end
+        end
+      end
+
+      -- Ingot recipes: set input and output counts to 1
+      if matchesPattern(recipeName, ingotPattern) then
+        if row.Inputs then
+          for _, input in ipairs(row.Inputs) do
+            input.Count = 1
+          end
+        end
+        if row.Outputs then
+          for _, output in ipairs(row.Outputs) do
+            output.Count = 1
+          end
+        end
+      end
+
+      -- Selected recipes: multiply inputs by factor, outputs by factor * (1 + bonus)
+      if matchesPattern(recipeName, selectionPattern) then
+        if row.Inputs then
+          for _, input in ipairs(row.Inputs) do
+            local oldCount = input.Count
+            input.Count = input.Count * factor
+            print("Recipe " .. recipeName .. " Input.Count: " .. oldCount .. " -> " .. input.Count)
+          end
+        end
+
+        if row.Outputs then
+          for _, output in ipairs(row.Outputs) do
+            local oldCount = output.Count
+            output.Count = math.floor(output.Count * factor * (1 + bonus))
+            print("Recipe " .. recipeName .. " Output.Count: " .. oldCount .. " -> " .. output.Count)
+          end
+        end
+      end
+    end
+`,
+	}
+
+	commands, err := ProcessJSON(content, command, "test.json")
+	if err != nil {
+		t.Fatalf("ProcessJSON failed: %v", err)
+	}
+
+	if len(commands) == 0 {
+		t.Fatal("Expected at least one command")
+	}
+
+	// Apply the commands
+	result := content
+	for _, cmd := range commands {
+		result = result[:cmd.From] + cmd.With + result[cmd.To:]
+	}
+
+	diff := cmp.Diff(result, expected)
+	if diff != "" {
+		t.Errorf("Differences:\n%s", diff)
+	}
+
+	// Check that the result matches expected (preserves formatting and changes weight)
+	if result != expected {
+		t.Errorf("Expected:\n%s\n\nGot:\n%s", expected, result)
+	}
+}
+
+func TestRetardedJSONEditing(t *testing.T) {
+	original := `{
+  "RowStruct": "/Script/Icarus.ItemableData",
+  "Defaults": {
+    "Behaviour": "None",
+    "DisplayName": "",
+    "Icon": "None",
+    "Override_Glow_Icon": "None",
+    "Description": "",
+    "FlavorText": "",
+    "Weight": 0,
+    "bAllowZeroWeight": false,
+    "MaxStack": 1
+  },
+  "Rows": [
+		{
+      "DisplayName": "NSLOCTEXT(\"D_Itemable\", \"Item_Fiber-DisplayName\", \"Fiber\")",
+      "Icon": "/Game/Assets/2DArt/UI/Items/Item_Icons/Resources/ITEM_Fibre.ITEM_Fibre",
+      "Description": "NSLOCTEXT(\"D_Itemable\", \"Item_Fiber-Description\", \"A bundle of soft fiber, highly useful.\")",
+      "FlavorText": "NSLOCTEXT(\"D_Itemable\", \"Item_Fiber-FlavorText\", \"Fiber is collected from bast, the strong inner bark of certain flowering plants.\")",
+      "Weight": 10,
+      "MaxStack": 200,
+      "Name": "Item_Fiber"
+    }
+	]
+}`
+
+	expected := `{
+  "RowStruct": "/Script/Icarus.ItemableData",
+  "Defaults": {
+    "Behaviour": "None",
+    "DisplayName": "",
+    "Icon": "None",
+    "Override_Glow_Icon": "None",
+    "Description": "",
+    "FlavorText": "",
+    "Weight": 0,
+    "bAllowZeroWeight": false,
+    "MaxStack": 1
+  },
+  "Rows": [
+		{
+      "DisplayName": "NSLOCTEXT(\"D_Itemable\", \"Item_Fiber-DisplayName\", \"Fiber\")",
+      "Icon": "/Game/Assets/2DArt/UI/Items/Item_Icons/Resources/ITEM_Fibre.ITEM_Fibre",
+      "Description": "NSLOCTEXT(\"D_Itemable\", \"Item_Fiber-Description\", \"A bundle of soft fiber, highly useful.\")",
+      "FlavorText": "NSLOCTEXT(\"D_Itemable\", \"Item_Fiber-FlavorText\", \"Fiber is collected from bast, the strong inner bark of certain flowering plants.\")",
+      "Weight": 10,
+      "MaxStack": 1000000,
+      "Name": "Item_Fiber"
+    }
+	]
+}`
+
+	command := utils.ModifyCommand{
+		Name: "test",
+		Lua: `
+    for _, row in ipairs(data.Rows) do
+      if row.MaxStack then
+        if string.find(row.Name, "Carrot") or string.find(row.Name, "Potato") then
+          row.MaxStack = 25
+        else
+          row.MaxStack = row.MaxStack * 10000
+          if row.MaxStack > 1000000 then
+            row.MaxStack = 1000000
+          end
+        end
+      end
+    end
+`,
+	}
+
+	commands, err := ProcessJSON(original, command, "test.json")
+	if err != nil {
+		t.Fatalf("ProcessJSON failed: %v", err)
+	}
+
+	if len(commands) == 0 {
+		t.Fatal("Expected at least one command")
+	}
+
+	// Apply the commands
+	result := original
+	for _, cmd := range commands {
+		result = result[:cmd.From] + cmd.With + result[cmd.To:]
+	}
+
+	diff := cmp.Diff(result, expected)
+	if diff != "" {
+		t.Errorf("Differences:\n%s", diff)
+	}
+
+	// Check that the weight was changed
+	if result != expected {
+		t.Errorf("Expected:\n%s\nGot:\n%s", expected, result)
+	}
+}
+
+func TestRetardedJSONEditing2(t *testing.T) {
+	original := `
+  {
+      "Rows": [
+        {
+            "Name": "Deep_Mining_Drill_Biofuel",
+            "Meshable": {
+                "RowName": "Mesh_Deep_Mining_Drill_Biofuel"
+            },
+            "Itemable": {
+                "RowName": "Item_Deep_Mining_Drill_Biofuel"
+            },
+            "Interactable": {
+                "RowName": "Deployable"
+            },
+            "Focusable": {
+                "RowName": "Focusable_1H"
+            },
+            "Highlightable": {
+                "RowName": "Generic"
+            },
+            "Actionable": {
+                "RowName": "Deployable"
+            },
+            "Usable": {
+                "RowName": "Place"
+            },
+            "Deployable": {
+                "RowName": "Deep_Mining_Drill_Biofuel"
+            },
+            "Durable": {
+                "RowName": "Deployable_750"
+            },
+            "Inventory": {
+                "RowName": "Deep_Mining_Drill_Biofuel"
+            },
+            "Decayable": {
+                "RowName": "Decay_MetaItem"
+            },
+            "Generator": {
+                "RowName": "Deep_Mining_Biofuel_Drill"
+            },
+            "Resource": {
+                "RowName": "Simple_Internal_Flow_Only"
+            },
+            "Manual_Tags": {
+                "GameplayTags": [
+                    {
+                        "TagName": "Item.Machine"
+                    }
+                ]
+            },
+            "Generated_Tags": {
+                "GameplayTags": [
+                    {
+                        "TagName": "Item.Machine"
+                    },
+                    {
+                        "TagName": "Traits.Meshable"
+                    },
+                    {
+                        "TagName": "Traits.Itemable"
+                    },
+                    {
+                        "TagName": "Traits.Interactable"
+                    },
+                    {
+                        "TagName": "Traits.Highlightable"
+                    },
+                    {
+                        "TagName": "Traits.Actionable"
+                    },
+                    {
+                        "TagName": "Traits.Usable"
+                    },
+                    {
+                        "TagName": "Traits.Deployable"
+                    },
+                    {
+                        "TagName": "Traits.Durable"
+                    },
+                    {
+                        "TagName": "Traits.Inventory"
+                    }
+                ],
+                "ParentTags": []
+            }
+        }
+      ]
+  }
+  `
+
+	expected := `
+  {
+      "Rows": [
+        {
+            "Name": "Deep_Mining_Drill_Biofuel",
+            "Meshable": {
+                "RowName": "Mesh_Deep_Mining_Drill_Biofuel"
+            },
+            "Itemable": {
+                "RowName": "Item_Deep_Mining_Drill_Biofuel"
+            },
+            "Interactable": {
+                "RowName": "Deployable"
+            },
+            "Focusable": {
+                "RowName": "Focusable_1H"
+            },
+            "Highlightable": {
+                "RowName": "Generic"
+            },
+            "Actionable": {
+                "RowName": "Deployable"
+            },
+            "Usable": {
+                "RowName": "Place"
+            },
+            "Deployable": {
+                "RowName": "Deep_Mining_Drill_Biofuel"
+            },
+            "Durable": {
+                "RowName": "Deployable_750"
+            },
+            "Inventory": {
+                "RowName": "Deep_Mining_Drill_Biofuel"
+            },
+            "Decayable": {
+                "RowName": "Decay_MetaItem"
+            },
+            "Generator": {
+                "RowName": "Deep_Mining_Biofuel_Drill"
+            },
+            "Resource": {
+                "RowName": "Simple_Internal_Flow_Only"
+            },
+            "Manual_Tags": {
+                "GameplayTags": [
+                    {
+                        "TagName": "Item.Machine"
+                    }
+                ]
+            },
+            "Generated_Tags": {
+                "GameplayTags": [
+                    {
+                        "TagName": "Item.Machine"
+                    },
+                    {
+                        "TagName": "Traits.Meshable"
+                    },
+                    {
+                        "TagName": "Traits.Itemable"
+                    },
+                    {
+                        "TagName": "Traits.Interactable"
+                    },
+                    {
+                        "TagName": "Traits.Highlightable"
+                    },
+                    {
+                        "TagName": "Traits.Actionable"
+                    },
+                    {
+                        "TagName": "Traits.Usable"
+                    },
+                    {
+                        "TagName": "Traits.Deployable"
+                    },
+                    {
+                        "TagName": "Traits.Durable"
+                    },
+                    {
+                        "TagName": "Traits.Inventory"
+                    }
+                ],
+                "ParentTags": []
+            }
+        ,"AdditionalStats": {"(Value=\"BaseDeepMiningDrillSpeed_+%\")":4000}}
+      ]
+  }
+  `
+
+	command := utils.ModifyCommand{
+		Name: "test",
+		Lua: `
+    for i, row in ipairs(data.Rows) do
+      -- Special case: Deep_Mining_Drill_Biofuel
+      if string.find(row.Name, "Deep_Mining_Drill_Biofuel") then
+        print("[DEBUG]  Special case: Deep_Mining_Drill_Biofuel")
+        if not row.AdditionalStats then
+          print("[DEBUG]   Creating AdditionalStats table for Deep_Mining_Drill_Biofuel")
+          row.AdditionalStats = {}
+        end
+        print("[DEBUG]   Setting BaseDeepMiningDrillSpeed_+% to 4000")
+        row.AdditionalStats["(Value=\\\"BaseDeepMiningDrillSpeed_+%\\\")"] = 4000
+      end
+    end
+`,
+	}
+
+	commands, err := ProcessJSON(original, command, "test.json")
+	if err != nil {
+		t.Fatalf("ProcessJSON failed: %v", err)
+	}
+
+	if len(commands) == 0 {
+		t.Fatal("Expected at least one command")
+	}
+
+	// Apply the commands
+	result := original
+	for _, cmd := range commands {
+		result = result[:cmd.From] + cmd.With + result[cmd.To:]
+	}
+
+	diff := cmp.Diff(result, expected)
+	if diff != "" {
+		t.Errorf("Differences:\n%s", diff)
+	}
+
+	if result != expected {
+		t.Errorf("Expected:\n%s\nGot:\n%s", expected, result)
+	}
+}

test_surgical.yml

@@ -0,0 +1,11 @@
+- name: SurgicalWeightTest
+  json: true
+  lua: |
+    -- This demonstrates surgical JSON editing
+    -- Only the Weight field of Item_Fiber will be modified
+    data.Rows[1].Weight = 999
+    modified = true
+  files:
+    - 'D_Itemable.json'
+  reset: false
+  loglevel: INFO 

toml_test.go

@@ -0,0 +1,513 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"cook/utils"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTOMLLoadBasic(t *testing.T) {
+	// Create a temporary directory for testing
+	tmpDir, err := os.MkdirTemp("", "toml-basic-test")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Create a simple TOML test file
+	tomlContent := `[[commands]]
+name = "SimpleTest"
+regex = "test = !num"
+lua = "v1 * 2"
+files = ["test.txt"]
+
+[[commands]]
+name = "AnotherTest"
+regex = "value = (!num)"
+lua = "v1 + 10"
+files = ["*.txt"]
+`
+
+	tomlFile := filepath.Join(tmpDir, "test.toml")
+	err = os.WriteFile(tomlFile, []byte(tomlContent), 0644)
+	if err != nil {
+		t.Fatalf("Failed to write TOML test file: %v", err)
+	}
+
+	// Change to temp directory
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	os.Chdir(tmpDir)
+
+	// Test loading TOML commands
+	commands, err := utils.LoadCommandsFromTomlFiles("test.toml")
+	assert.NoError(t, err, "Should load TOML commands without error")
+	assert.Len(t, commands, 2, "Should load 2 commands from TOML")
+
+	// Verify first command
+	assert.Equal(t, "SimpleTest", commands[0].Name, "First command name should match")
+	assert.Equal(t, "test = !num", commands[0].Regex, "First command regex should match")
+	assert.Equal(t, "v1 * 2", commands[0].Lua, "First command Lua should match")
+	assert.Equal(t, []string{"test.txt"}, commands[0].Files, "First command files should match")
+
+	// Verify second command
+	assert.Equal(t, "AnotherTest", commands[1].Name, "Second command name should match")
+	assert.Equal(t, "value = (!num)", commands[1].Regex, "Second command regex should match")
+	assert.Equal(t, "v1 + 10", commands[1].Lua, "Second command Lua should match")
+	assert.Equal(t, []string{"*.txt"}, commands[1].Files, "Second command files should match")
+}
+
+func TestTOMLGlobalModifiers(t *testing.T) {
+	// Create a temporary directory for testing
+	tmpDir, err := os.MkdirTemp("", "toml-global-modifiers-test")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Create TOML content with global modifiers
+	tomlContent := `[[commands]]
+modifiers = { multiplier = 3, prefix = "TEST_", enabled = true }
+
+[[commands]]
+name = "UseGlobalModifiers"
+regex = "value = !num"
+lua = "v1 * multiplier; s1 = prefix .. s1"
+files = ["test.txt"]
+`
+
+	tomlFile := filepath.Join(tmpDir, "test.toml")
+	err = os.WriteFile(tomlFile, []byte(tomlContent), 0644)
+	if err != nil {
+		t.Fatalf("Failed to write TOML test file: %v", err)
+	}
+
+	// Change to temp directory
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	os.Chdir(tmpDir)
+
+	// Test loading TOML commands
+	commands, err := utils.LoadCommandsFromTomlFiles("test.toml")
+	assert.NoError(t, err, "Should load TOML commands without error")
+	assert.Len(t, commands, 2, "Should load 2 commands from TOML")
+
+	// Verify global modifiers command (first command should have only modifiers)
+	assert.Empty(t, commands[0].Name, "Global modifiers command should have no name")
+	assert.Empty(t, commands[0].Regex, "Global modifiers command should have no regex")
+	assert.Empty(t, commands[0].Lua, "Global modifiers command should have no lua")
+	assert.Empty(t, commands[0].Files, "Global modifiers command should have no files")
+	assert.Len(t, commands[0].Modifiers, 3, "Global modifiers command should have 3 modifiers")
+	assert.Equal(t, int64(3), commands[0].Modifiers["multiplier"], "Multiplier should be 3")
+	assert.Equal(t, "TEST_", commands[0].Modifiers["prefix"], "Prefix should be TEST_")
+	assert.Equal(t, true, commands[0].Modifiers["enabled"], "Enabled should be true")
+
+	// Verify regular command
+	assert.Equal(t, "UseGlobalModifiers", commands[1].Name, "Regular command name should match")
+	assert.Equal(t, "value = !num", commands[1].Regex, "Regular command regex should match")
+}
+
+func TestTOMLMultilineRegex(t *testing.T) {
+	// Create a temporary directory for testing
+	tmpDir, err := os.MkdirTemp("", "toml-multiline-test")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Create TOML content with multiline regex using literal strings
+	tomlContent := `[[commands]]
+modifiers = { factor = 2.5 }
+
+[[commands]]
+name = "MultilineTest"
+regex = '''
+\[config\.settings\]
+
+    depth = !num
+
+    width = !num
+
+    height = !num'''
+lua = "v1 * factor"
+files = ["test.conf"]
+isolate = true
+`
+
+	tomlFile := filepath.Join(tmpDir, "test.toml")
+	err = os.WriteFile(tomlFile, []byte(tomlContent), 0644)
+	if err != nil {
+		t.Fatalf("Failed to write TOML test file: %v", err)
+	}
+
+	// Create test file that matches the multiline pattern
+	testContent := `[config.settings]
+
+    depth = 10
+
+    width = 20
+
+    height = 30
+`
+
+	testFile := filepath.Join(tmpDir, "test.conf")
+	err = os.WriteFile(testFile, []byte(testContent), 0644)
+	if err != nil {
+		t.Fatalf("Failed to write test file: %v", err)
+	}
+
+	// Change to temp directory
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	os.Chdir(tmpDir)
+
+	// Test loading TOML commands
+	commands, err := utils.LoadCommandsFromTomlFiles("test.toml")
+	assert.NoError(t, err, "Should load TOML commands without error")
+	assert.Len(t, commands, 2, "Should load 2 commands from TOML")
+
+	// Verify the multiline regex command
+	multilineCmd := commands[1]
+	assert.Equal(t, "MultilineTest", multilineCmd.Name, "Command name should match")
+	assert.Contains(t, multilineCmd.Regex, "\\[config\\.settings\\]", "Regex should contain escaped brackets")
+	assert.Contains(t, multilineCmd.Regex, "depth = !num", "Regex should contain depth pattern")
+	assert.Contains(t, multilineCmd.Regex, "width = !num", "Regex should contain width pattern")
+	assert.Contains(t, multilineCmd.Regex, "height = !num", "Regex should contain height pattern")
+	assert.Contains(t, multilineCmd.Regex, "\n", "Regex should contain newlines")
+	assert.True(t, multilineCmd.Isolate, "Isolate should be true")
+
+	// Verify the regex preserves proper structure
+	expectedLines := []string{
+		"\\[config\\.settings\\]",
+		"depth = !num",
+		"width = !num",
+		"height = !num",
+	}
+
+	for _, line := range expectedLines {
+		assert.Contains(t, multilineCmd.Regex, line, "Regex should contain: "+line)
+	}
+}
+
+func TestTOMLComplexRegexPatterns(t *testing.T) {
+	// Create a temporary directory for testing
+	tmpDir, err := os.MkdirTemp("", "toml-complex-regex-test")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Create TOML content with complex regex patterns
+	tomlContent := `[[commands]]
+name = "ComplexPatterns"
+regexes = [
+    "\\[section\\.([^\\]]+)\\]",
+    "(?P<key>\\w+)\\s*=\\s*(?P<value>\\d+\\.\\d+)",
+    "network\\.(\\w+)\\.(enable|disable)"
+]
+lua = "if is_number(value) then value = num(value) * 1.1 end; return true"
+files = ["*.conf", "*.ini"]
+`
+
+	tomlFile := filepath.Join(tmpDir, "test.toml")
+	err = os.WriteFile(tomlFile, []byte(tomlContent), 0644)
+	if err != nil {
+		t.Fatalf("Failed to write TOML test file: %v", err)
+	}
+
+	// Change to temp directory
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	os.Chdir(tmpDir)
+
+	// Test loading TOML commands
+	commands, err := utils.LoadCommandsFromTomlFiles("test.toml")
+	assert.NoError(t, err, "Should load TOML commands without error")
+	assert.Len(t, commands, 1, "Should load 1 command from TOML")
+
+	// Verify the complex regex command
+	cmd := commands[0]
+	assert.Equal(t, "ComplexPatterns", cmd.Name, "Command name should match")
+	assert.Len(t, cmd.Regexes, 3, "Should have 3 regex patterns")
+
+	// Verify each regex pattern
+	assert.Equal(t, `\[section\.([^\]]+)\]`, cmd.Regexes[0], "First regex should match section pattern")
+	assert.Equal(t, `(?P<key>\w+)\s*=\s*(?P<value>\d+\.\d+)`, cmd.Regexes[1], "Second regex should match key-value pattern")
+	assert.Equal(t, `network\.(\w+)\.(enable|disable)`, cmd.Regexes[2], "Third regex should match network pattern")
+
+	assert.Equal(t, []string{"*.conf", "*.ini"}, cmd.Files, "Files should match")
+}
+
+func TestTOMLJSONMode(t *testing.T) {
+	// Create a temporary directory for testing
+	tmpDir, err := os.MkdirTemp("", "toml-json-test")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Create TOML content with JSON mode commands
+	tomlContent := `[[commands]]
+name = "JSONMultiply"
+json = true
+lua = "for i, item in ipairs(data.items) do data.items[i].value = item.value * 2 end; return true"
+files = ["data.json"]
+
+[[commands]]
+name = "JSONObjectUpdate"
+json = true
+lua = "data.version = '2.0.0'; data.enabled = true; return true"
+files = ["config.json"]
+`
+
+	tomlFile := filepath.Join(tmpDir, "test.toml")
+	err = os.WriteFile(tomlFile, []byte(tomlContent), 0644)
+	if err != nil {
+		t.Fatalf("Failed to write TOML test file: %v", err)
+	}
+
+	// Change to temp directory
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	os.Chdir(tmpDir)
+
+	// Test loading TOML commands
+	commands, err := utils.LoadCommandsFromTomlFiles("test.toml")
+	assert.NoError(t, err, "Should load TOML commands without error")
+	assert.Len(t, commands, 2, "Should load 2 commands from TOML")
+
+	// Verify first JSON command
+	cmd1 := commands[0]
+	assert.Equal(t, "JSONMultiply", cmd1.Name, "First command name should match")
+	assert.True(t, cmd1.JSON, "First command should have JSON mode enabled")
+	assert.Equal(t, "for i, item in ipairs(data.items) do data.items[i].value = item.value * 2 end; return true", cmd1.Lua, "First command Lua should match")
+	assert.Equal(t, []string{"data.json"}, cmd1.Files, "First command files should match")
+
+	// Verify second JSON command
+	cmd2 := commands[1]
+	assert.Equal(t, "JSONObjectUpdate", cmd2.Name, "Second command name should match")
+	assert.True(t, cmd2.JSON, "Second command should have JSON mode enabled")
+	assert.Equal(t, "data.version = '2.0.0'; data.enabled = true; return true", cmd2.Lua, "Second command Lua should match")
+	assert.Equal(t, []string{"config.json"}, cmd2.Files, "Second command files should match")
+}
+
+func TestTOMLEndToEndIntegration(t *testing.T) {
+	// Create a temporary directory for testing
+	tmpDir, err := os.MkdirTemp("", "toml-integration-test")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Create comprehensive TOML content
+	tomlContent := `[[commands]]
+modifiers = { multiplier = 4, base_value = 100 }
+
+[[commands]]
+name = "IntegrationTest"
+regex = '''
+\[kinetics\.stressValues\.v2\.capacity\]
+
+    steam_engine = !num
+
+    water_wheel = !num
+
+    copper_valve_handle = !num'''
+lua = "v1 * multiplier"
+files = ["test.txt"]
+isolate = true
+
+[[commands]]
+name = "SimplePattern"
+regex = "enabled = (true|false)"
+lua = "= false"
+files = ["test.txt"]
+`
+
+	tomlFile := filepath.Join(tmpDir, "test.toml")
+	err = os.WriteFile(tomlFile, []byte(tomlContent), 0644)
+	if err != nil {
+		t.Fatalf("Failed to write TOML test file: %v", err)
+	}
+
+	// Create test file that matches the patterns
+	testContent := `[kinetics.stressValues.v2.capacity]
+
+    steam_engine = 256
+
+    water_wheel = 64
+
+    copper_valve_handle = 16
+
+some_other_setting = enabled = true
+`
+
+	testFile := filepath.Join(tmpDir, "test.txt")
+	err = os.WriteFile(testFile, []byte(testContent), 0644)
+	if err != nil {
+		t.Fatalf("Failed to write test file: %v", err)
+	}
+
+	// Change to temp directory
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	os.Chdir(tmpDir)
+
+	// Test the complete workflow using the main function
+	commands, err := utils.LoadCommands([]string{"test.toml"})
+	assert.NoError(t, err, "Should load TOML commands without error")
+	assert.Len(t, commands, 3, "Should load 3 commands total (including global modifiers)")
+
+	// Associate files with commands
+	files := []string{"test.txt"}
+	associations, err := utils.AssociateFilesWithCommands(files, commands)
+	assert.NoError(t, err, "Should associate files with commands")
+
+	// Verify associations
+	association := associations["test.txt"]
+	assert.Len(t, association.IsolateCommands, 1, "Should have 1 isolate command")
+	assert.Len(t, association.Commands, 1, "Should have 1 regular command")
+	assert.Equal(t, "IntegrationTest", association.IsolateCommands[0].Name, "Isolate command should match")
+	assert.Equal(t, "SimplePattern", association.Commands[0].Name, "Regular command should match")
+
+	t.Logf("TOML integration test completed successfully")
+	t.Logf("Loaded %d commands from TOML", len(commands))
+	t.Logf("Associated commands: %d isolate, %d regular",
+		len(association.IsolateCommands), len(association.Commands))
+}
+
+func TestTOMLErrorHandling(t *testing.T) {
+	// Create a temporary directory for testing
+	tmpDir, err := os.MkdirTemp("", "toml-error-test")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Change to temp directory
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	os.Chdir(tmpDir)
+
+	// Test 1: Invalid TOML syntax
+	invalidTOML := `[[commands]]
+name = "Invalid"
+regex = "test = !num"
+lua = "v1 * 2"
+files = ["test.txt"
+# Missing closing bracket
+`
+
+	invalidFile := filepath.Join(tmpDir, "invalid.toml")
+	err = os.WriteFile(invalidFile, []byte(invalidTOML), 0644)
+	assert.NoError(t, err, "Should write invalid TOML file")
+
+	commands, err := utils.LoadCommandsFromTomlFiles("invalid.toml")
+	assert.Error(t, err, "Should return error for invalid TOML syntax")
+	assert.Nil(t, commands, "Should return nil commands for invalid TOML")
+	assert.Contains(t, err.Error(), "failed to unmarshal TOML file", "Error should mention TOML unmarshaling")
+
+	// Test 2: Non-existent file
+	commands, err = utils.LoadCommandsFromTomlFiles("nonexistent.toml")
+	assert.NoError(t, err, "Should handle non-existent file without error")
+	assert.Empty(t, commands, "Should return empty commands for non-existent file")
+
+	// Test 3: Empty TOML file creates an error (this is expected behavior)
+	emptyFile := filepath.Join(tmpDir, "empty.toml")
+	err = os.WriteFile(emptyFile, []byte(""), 0644)
+	assert.NoError(t, err, "Should write empty TOML file")
+
+	commands, err = utils.LoadCommandsFromTomlFiles("empty.toml")
+	assert.Error(t, err, "Should return error for empty TOML file")
+	assert.Nil(t, commands, "Should return nil commands for empty TOML")
+}
+
+func TestYAMLToTOMLConversion(t *testing.T) {
+	// Create a temporary directory for testing
+	tmpDir, err := os.MkdirTemp("", "yaml-to-toml-conversion-test")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Change to temp directory
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+	os.Chdir(tmpDir)
+
+	// Create a test YAML file
+	yamlContent := `- name: "ConversionTest"
+  regex: "value = !num"
+  lua: "v1 * 3"
+  files: ["test.txt"]
+  loglevel: DEBUG
+
+- name: "AnotherTest"
+  regex: "enabled = (true|false)"
+  lua: "= false"
+  files: ["*.conf"]
+
+- name: "GlobalModifiers"
+  modifiers:
+    multiplier: 2.5
+    prefix: "CONV_"
+`
+
+	yamlFile := filepath.Join(tmpDir, "test.yml")
+	err = os.WriteFile(yamlFile, []byte(yamlContent), 0644)
+	assert.NoError(t, err, "Should write YAML test file")
+
+	// Test conversion
+	err = utils.ConvertYAMLToTOML("test.yml")
+	assert.NoError(t, err, "Should convert YAML to TOML without error")
+
+	// Check that TOML file was created
+	tomlFile := filepath.Join(tmpDir, "test.toml")
+	_, err = os.Stat(tomlFile)
+	assert.NoError(t, err, "TOML file should exist after conversion")
+
+	// Read and verify TOML content
+	tomlData, err := os.ReadFile(tomlFile)
+	assert.NoError(t, err, "Should read TOML file")
+
+	tomlContent := string(tomlData)
+	assert.Contains(t, tomlContent, `name = "ConversionTest"`, "TOML should contain first command name")
+	assert.Contains(t, tomlContent, `name = "AnotherTest"`, "TOML should contain second command name")
+	assert.Contains(t, tomlContent, `name = "GlobalModifiers"`, "TOML should contain global modifiers command")
+	assert.Contains(t, tomlContent, `multiplier = 2.5`, "TOML should contain multiplier")
+	assert.Contains(t, tomlContent, `prefix = "CONV_"`, "TOML should contain prefix")
+
+	// Test that converted TOML loads correctly
+	commands, err := utils.LoadCommandsFromTomlFiles("test.toml")
+	assert.NoError(t, err, "Should load converted TOML without error")
+	assert.Len(t, commands, 3, "Should load 3 commands from converted TOML")
+
+	// Find global modifiers command (it might not be first)
+	var globalCmd utils.ModifyCommand
+	foundGlobal := false
+	for _, cmd := range commands {
+		if cmd.Name == "GlobalModifiers" {
+			globalCmd = cmd
+			foundGlobal = true
+			break
+		}
+	}
+	assert.True(t, foundGlobal, "Should find global modifiers command")
+	assert.Equal(t, 2.5, globalCmd.Modifiers["multiplier"], "Should preserve multiplier value")
+	assert.Equal(t, "CONV_", globalCmd.Modifiers["prefix"], "Should preserve prefix value")
+
+	// Test skip functionality - run conversion again
+	err = utils.ConvertYAMLToTOML("test.yml")
+	assert.NoError(t, err, "Should handle existing TOML file without error")
+
+	// Verify original TOML file wasn't modified
+	originalTomlData, err := os.ReadFile(tomlFile)
+	assert.NoError(t, err, "Should read TOML file again")
+	assert.Equal(t, tomlData, originalTomlData, "TOML file content should be unchanged")
+
+	t.Logf("YAML to TOML conversion test completed successfully")
+}

utils/db.go

@@ -1,6 +1,7 @@
 package utils
 
 import (
+	"errors"
 	"path/filepath"
 	"time"
 
@@ -41,24 +42,25 @@ func GetDB() (DB, error) {
 
 	dbFile := filepath.Join("data.sqlite")
 	getDBLogger.Debug("Opening database file: %q", dbFile)
+	getDBLogger.Trace("Database configuration: PrepareStmt=true, GORM logger=Silent")
 	db, err := gorm.Open(sqlite.Open(dbFile), &gorm.Config{
 		// SkipDefaultTransaction: true,
 		PrepareStmt: true,
 		Logger:      gormlogger.Default.LogMode(gormlogger.Silent),
 	})
 	if err != nil {
-		getDBLogger.Error("Failed to open database: %v", err)
+		getDBLogger.Error("Failed to open database file %q: %v", dbFile, err)
 		return nil, err
 	}
-	getDBLogger.Debug("Database opened successfully, running auto migration")
+	getDBLogger.Debug("Database opened successfully, running auto migration for FileSnapshot model")
 	if err := db.AutoMigrate(&FileSnapshot{}); err != nil {
-		getDBLogger.Error("Auto migration failed: %v", err)
+		getDBLogger.Error("Auto migration failed for FileSnapshot model: %v", err)
 		return nil, err
 	}
-	getDBLogger.Debug("Auto migration completed")
+	getDBLogger.Info("Database initialized and migrated successfully")
 
 	globalDB = &DBWrapper{db: db}
-	getDBLogger.Debug("Database wrapper initialized")
+	getDBLogger.Debug("Database wrapper initialized and cached globally")
 	return globalDB, nil
 }
 
@@ -88,7 +90,7 @@ func (db *DBWrapper) FileExists(filePath string) (bool, error) {
 }
 
 func (db *DBWrapper) SaveFile(filePath string, fileData []byte) error {
-	saveFileLogger := dbLogger.WithPrefix("SaveFile").WithField("filePath", filePath)
+	saveFileLogger := dbLogger.WithPrefix("SaveFile").WithField("filePath", filePath).WithField("dataSize", len(fileData))
 	saveFileLogger.Debug("Attempting to save file to database")
 	saveFileLogger.Trace("File data length: %d", len(fileData))
 
@@ -98,7 +100,7 @@ func (db *DBWrapper) SaveFile(filePath string, fileData []byte) error {
 		return err
 	}
 	if exists {
-		saveFileLogger.Debug("File already exists, skipping save")
+		saveFileLogger.Debug("File already exists in database, skipping save to avoid overwriting original snapshot")
 		return nil
 	}
 	saveFileLogger.Debug("Creating new file snapshot in database")
@@ -110,7 +112,7 @@ func (db *DBWrapper) SaveFile(filePath string, fileData []byte) error {
 	if err != nil {
 		saveFileLogger.Error("Failed to create file snapshot: %v", err)
 	} else {
-		saveFileLogger.Debug("File saved successfully to database")
+		saveFileLogger.Info("File successfully saved to database")
 	}
 	return err
 }
@@ -121,8 +123,11 @@ func (db *DBWrapper) GetFile(filePath string) ([]byte, error) {
 	var fileSnapshot FileSnapshot
 	err := db.db.Model(&FileSnapshot{}).Where("file_path = ?", filePath).First(&fileSnapshot).Error
 	if err != nil {
-		// Downgrade not-found to warning to avoid noisy errors during first run
-		getFileLogger.Warning("Failed to get file from database: %v", err)
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			getFileLogger.Debug("File not found in database: %v", err)
+		} else {
+			getFileLogger.Warning("Failed to get file from database: %v", err)
+		}
 		return nil, err
 	}
 	getFileLogger.Debug("File found in database")

utils/file.go

@@ -2,7 +2,6 @@ package utils
 
 import (
 	"os"
-	"path/filepath"
 	"strconv"
 	"strings"
 
@@ -13,34 +12,13 @@ import (
 var fileLogger = logger.Default.WithPrefix("utils/file")
 
 func CleanPath(path string) string {
-	cleanPathLogger := fileLogger.WithPrefix("CleanPath")
-	cleanPathLogger.Debug("Cleaning path: %q", path)
-	cleanPathLogger.Trace("Original path: %q", path)
-	path = filepath.Clean(path)
-	path = strings.ReplaceAll(path, "\\", "/")
-	cleanPathLogger.Trace("Cleaned path result: %q", path)
-	return path
+	// Use the centralized ResolvePath function
+	return ResolvePath(path)
 }
 
 func ToAbs(path string) string {
-	toAbsLogger := fileLogger.WithPrefix("ToAbs")
-	toAbsLogger.Debug("Converting path to absolute: %q", path)
-	toAbsLogger.Trace("Input path: %q", path)
-	if filepath.IsAbs(path) {
-		toAbsLogger.Debug("Path is already absolute, cleaning it.")
-		cleanedPath := CleanPath(path)
-		toAbsLogger.Trace("Already absolute path after cleaning: %q", cleanedPath)
-		return cleanedPath
-	}
-	cwd, err := os.Getwd()
-	if err != nil {
-		toAbsLogger.Error("Error getting current working directory: %v", err)
-		return CleanPath(path)
-	}
-	toAbsLogger.Trace("Current working directory: %q", cwd)
-	cleanedPath := CleanPath(filepath.Join(cwd, path))
-	toAbsLogger.Trace("Converted absolute path result: %q", cleanedPath)
-	return cleanedPath
+	// Use the centralized ResolvePath function
+	return ResolvePath(path)
 }
 
 // LimitString truncates a string to maxLen and adds "..." if truncated

utils/flags.go

@@ -1,21 +0,0 @@
-package utils
-
-import (
-	"flag"
-
-	logger "git.site.quack-lab.dev/dave/cylogger"
-)
-
-// flagsLogger is a scoped logger for the utils/flags package.
-var flagsLogger = logger.Default.WithPrefix("utils/flags")
-
-var (
-	ParallelFiles = flag.Int("P", 100, "Number of files to process in parallel")
-	Filter        = flag.String("f", "", "Filter commands before running them")
-	JSON          = flag.Bool("json", false, "Enable JSON mode for processing JSON files")
-)
-
-func init() {
-	flagsLogger.Debug("Initializing flags")
-	flagsLogger.Trace("ParallelFiles initial value: %d, Filter initial value: %q, JSON initial value: %t", *ParallelFiles, *Filter, *JSON)
-}

utils/modifycommand.go

@@ -8,6 +8,7 @@ import (
 
 	logger "git.site.quack-lab.dev/dave/cylogger"
 	"github.com/bmatcuk/doublestar/v4"
+	"github.com/BurntSushi/toml"
 	"gopkg.in/yaml.v3"
 )
 
@@ -15,18 +16,18 @@ import (
 var modifyCommandLogger = logger.Default.WithPrefix("utils/modifycommand")
 
 type ModifyCommand struct {
-	Name      string                 `yaml:"name,omitempty"`
-	Regex     string                 `yaml:"regex,omitempty"`
-	Regexes   []string               `yaml:"regexes,omitempty"`
-	Lua       string                 `yaml:"lua,omitempty"`
-	Files     []string               `yaml:"files,omitempty"`
-	Reset     bool                   `yaml:"reset,omitempty"`
-	LogLevel  string                 `yaml:"loglevel,omitempty"`
-	Isolate   bool                   `yaml:"isolate,omitempty"`
-	NoDedup   bool                   `yaml:"nodedup,omitempty"`
-	Disabled  bool                   `yaml:"disable,omitempty"`
-	JSON      bool                   `yaml:"json,omitempty"`
-	Modifiers map[string]interface{} `yaml:"modifiers,omitempty"`
+	Name      string                 `yaml:"name,omitempty" toml:"name,omitempty"`
+	Regex     string                 `yaml:"regex,omitempty" toml:"regex,omitempty"`
+	Regexes   []string               `yaml:"regexes,omitempty" toml:"regexes,omitempty"`
+	Lua       string                 `yaml:"lua,omitempty" toml:"lua,omitempty"`
+	Files     []string               `yaml:"files,omitempty" toml:"files,omitempty"`
+	Reset     bool                   `yaml:"reset,omitempty" toml:"reset,omitempty"`
+	LogLevel  string                 `yaml:"loglevel,omitempty" toml:"loglevel,omitempty"`
+	Isolate   bool                   `yaml:"isolate,omitempty" toml:"isolate,omitempty"`
+	NoDedup   bool                   `yaml:"nodedup,omitempty" toml:"nodedup,omitempty"`
+	Disabled  bool                   `yaml:"disable,omitempty" toml:"disable,omitempty"`
+	JSON      bool                   `yaml:"json,omitempty" toml:"json,omitempty"`
+	Modifiers map[string]interface{} `yaml:"modifiers,omitempty" toml:"modifiers,omitempty"`
 }
 
 type CookFile []ModifyCommand
@@ -84,25 +85,27 @@ func SplitPattern(pattern string) (string, string) {
 	splitPatternLogger := modifyCommandLogger.WithPrefix("SplitPattern").WithField("pattern", pattern)
 	splitPatternLogger.Debug("Splitting pattern")
 	splitPatternLogger.Trace("Original pattern: %q", pattern)
-	static, pattern := doublestar.SplitPattern(pattern)
 
-	cwd, err := os.Getwd()
-	if err != nil {
-		splitPatternLogger.Error("Error getting current working directory: %v", err)
-		return "", ""
-	}
-	splitPatternLogger.Trace("Current working directory: %q", cwd)
+	// Resolve the pattern first to handle ~ expansion and make it absolute
+	resolvedPattern := ResolvePath(pattern)
+	splitPatternLogger.Trace("Resolved pattern: %q", resolvedPattern)
+
+	static, pattern := doublestar.SplitPattern(resolvedPattern)
+
+	// Ensure static part is properly resolved
 	if static == "" {
-		splitPatternLogger.Debug("Static part is empty, defaulting to current working directory")
+		cwd, err := os.Getwd()
+		if err != nil {
+			splitPatternLogger.Error("Error getting current working directory: %v", err)
+			return "", ""
+		}
 		static = cwd
+		splitPatternLogger.Debug("Static part is empty, defaulting to current working directory: %q", static)
+	} else {
+		// Static part should already be resolved by ResolvePath
+		static = strings.ReplaceAll(static, "\\", "/")
 	}
-	if !filepath.IsAbs(static) {
-		splitPatternLogger.Debug("Static part is not absolute, joining with current working directory")
-		static = filepath.Join(cwd, static)
-		static = filepath.Clean(static)
-		splitPatternLogger.Trace("Static path after joining and cleaning: %q", static)
-	}
-	static = strings.ReplaceAll(static, "\\", "/")
+
 	splitPatternLogger.Trace("Final static path: %q, Remaining pattern: %q", static, pattern)
 	return static, pattern
 }
@@ -122,33 +125,23 @@ func AssociateFilesWithCommands(files []string, commands []ModifyCommand) (map[s
 	fileCommands := make(map[string]FileCommandAssociation)
 
 	for _, file := range files {
-		file = strings.ReplaceAll(file, "\\", "/")
-		associateFilesLogger.Debug("Processing file: %q", file)
+		// Use centralized path resolution internally but keep original file as key
+		resolvedFile := ResolvePath(file)
+		associateFilesLogger.Debug("Processing file: %q (resolved: %q)", file, resolvedFile)
 		fileCommands[file] = FileCommandAssociation{
-			File:            file,
+			File:            resolvedFile,
 			IsolateCommands: []ModifyCommand{},
 			Commands:        []ModifyCommand{},
 		}
 		for _, command := range commands {
 			associateFilesLogger.Debug("Checking command %q for file %q", command.Name, file)
 			for _, glob := range command.Files {
-				glob = strings.ReplaceAll(glob, "\\", "/")
+				// SplitPattern now handles tilde expansion and path resolution
 				static, pattern := SplitPattern(glob)
 				associateFilesLogger.Trace("Glob parts for %q → static=%q pattern=%q", glob, static, pattern)
 
-				// Build absolute path for the current file to compare with static
-				cwd, err := os.Getwd()
-				if err != nil {
-					associateFilesLogger.Warning("Failed to get CWD when matching %q for file %q: %v", glob, file, err)
-					continue
-				}
-				var absFile string
-				if filepath.IsAbs(file) {
-					absFile = filepath.Clean(file)
-				} else {
-					absFile = filepath.Clean(filepath.Join(cwd, file))
-				}
-				absFile = strings.ReplaceAll(absFile, "\\", "/")
+				// Use resolved file for matching
+				absFile := resolvedFile
 				associateFilesLogger.Trace("Absolute file path resolved for matching: %q", absFile)
 
 				// Only match if the file is under the static root
@@ -199,9 +192,14 @@ func AggregateGlobs(commands []ModifyCommand) map[string]struct{} {
 	for _, command := range commands {
 		aggregateGlobsLogger.Debug("Processing command %q for glob patterns", command.Name)
 		for _, glob := range command.Files {
-			resolvedGlob := strings.Replace(glob, "~", os.Getenv("HOME"), 1)
-			resolvedGlob = strings.ReplaceAll(resolvedGlob, "\\", "/")
-			aggregateGlobsLogger.Trace("Adding glob: %q (resolved to %q)", glob, resolvedGlob)
+			// Split the glob into static and pattern parts, then resolve ONLY the static part
+			static, pattern := SplitPattern(glob)
+			// Reconstruct the glob with resolved static part
+			resolvedGlob := static
+			if pattern != "" {
+				resolvedGlob += "/" + pattern
+			}
+			aggregateGlobsLogger.Trace("Adding glob: %q (resolved to %q) [static=%s, pattern=%s]", glob, resolvedGlob, static, pattern)
 			globs[resolvedGlob] = struct{}{}
 		}
 	}
@@ -235,15 +233,16 @@ func ExpandGLobs(patterns map[string]struct{}) ([]string, error) {
 		expandGlobsLogger.Debug("Found %d matches for pattern %q", len(matches), pattern)
 		expandGlobsLogger.Trace("Raw matches for pattern %q: %v", pattern, matches)
 		for _, m := range matches {
-			m = filepath.Join(static, m)
-			info, err := os.Stat(m)
+			// Resolve the full path
+			fullPath := ResolvePath(filepath.Join(static, m))
+			info, err := os.Stat(fullPath)
 			if err != nil {
-				expandGlobsLogger.Warning("Error getting file info for %q: %v", m, err)
+				expandGlobsLogger.Warning("Error getting file info for %q: %v", fullPath, err)
 				continue
 			}
-			if !info.IsDir() && !filesMap[m] {
-				expandGlobsLogger.Trace("Adding unique file to list: %q", m)
-				filesMap[m], files = true, append(files, m)
+			if !info.IsDir() && !filesMap[fullPath] {
+				expandGlobsLogger.Trace("Adding unique file to list: %q", fullPath)
+				filesMap[fullPath], files = true, append(files, fullPath)
 			}
 		}
 	}
@@ -265,11 +264,27 @@ func LoadCommands(args []string) ([]ModifyCommand, error) {
 
 	for _, arg := range args {
 		loadCommandsLogger.Debug("Processing argument for commands: %q", arg)
-		newCommands, err := LoadCommandsFromCookFiles(arg)
-		if err != nil {
-			loadCommandsLogger.Error("Failed to load commands from argument %q: %v", arg, err)
-			return nil, fmt.Errorf("failed to load commands from cook files: %w", err)
+		var newCommands []ModifyCommand
+		var err error
+
+		// Check file extension to determine format
+		if strings.HasSuffix(arg, ".toml") {
+			loadCommandsLogger.Debug("Loading TOML commands from %q", arg)
+			newCommands, err = LoadCommandsFromTomlFiles(arg)
+			if err != nil {
+				loadCommandsLogger.Error("Failed to load TOML commands from argument %q: %v", arg, err)
+				return nil, fmt.Errorf("failed to load commands from TOML files: %w", err)
+			}
+		} else {
+			// Default to YAML for .yml, .yaml, or any other extension
+			loadCommandsLogger.Debug("Loading YAML commands from %q", arg)
+			newCommands, err = LoadCommandsFromCookFiles(arg)
+			if err != nil {
+				loadCommandsLogger.Error("Failed to load YAML commands from argument %q: %v", arg, err)
+				return nil, fmt.Errorf("failed to load commands from cook files: %w", err)
+			}
 		}
+
 		loadCommandsLogger.Debug("Successfully loaded %d commands from %q", len(newCommands), arg)
 		for _, cmd := range newCommands {
 			if cmd.Disabled {
@@ -300,9 +315,8 @@ func LoadCommandsFromCookFiles(pattern string) ([]ModifyCommand, error) {
 	loadCookFilesLogger.Trace("Cook files found: %v", cookFiles)
 
 	for _, cookFile := range cookFiles {
-		cookFile = filepath.Join(static, cookFile)
-		cookFile = filepath.Clean(cookFile)
-		cookFile = strings.ReplaceAll(cookFile, "\\", "/")
+		// Use centralized path resolution
+		cookFile = ResolvePath(filepath.Join(static, cookFile))
 		loadCookFilesLogger.Debug("Loading commands from individual cook file: %q", cookFile)
 
 		cookFileData, err := os.ReadFile(cookFile)
@@ -373,3 +387,189 @@ func FilterCommands(commands []ModifyCommand, filter string) []ModifyCommand {
 	filterCommandsLogger.Trace("Filtered commands: %v", filteredCommands)
 	return filteredCommands
 }
+
+func LoadCommandsFromTomlFiles(pattern string) ([]ModifyCommand, error) {
+	loadTomlFilesLogger := modifyCommandLogger.WithPrefix("LoadCommandsFromTomlFiles").WithField("pattern", pattern)
+	loadTomlFilesLogger.Debug("Loading commands from TOML files based on pattern")
+	loadTomlFilesLogger.Trace("Input pattern: %q", pattern)
+	static, pattern := SplitPattern(pattern)
+	commands := []ModifyCommand{}
+	tomlFiles, err := doublestar.Glob(os.DirFS(static), pattern)
+	if err != nil {
+		loadTomlFilesLogger.Error("Failed to glob TOML files for pattern %q: %v", pattern, err)
+		return nil, fmt.Errorf("failed to glob TOML files: %w", err)
+	}
+	loadTomlFilesLogger.Debug("Found %d TOML files for pattern %q", len(tomlFiles), pattern)
+	loadTomlFilesLogger.Trace("TOML files found: %v", tomlFiles)
+
+	for _, tomlFile := range tomlFiles {
+		// Use centralized path resolution
+		tomlFile = ResolvePath(filepath.Join(static, tomlFile))
+		loadTomlFilesLogger.Debug("Loading commands from individual TOML file: %q", tomlFile)
+
+		tomlFileData, err := os.ReadFile(tomlFile)
+		if err != nil {
+			loadTomlFilesLogger.Error("Failed to read TOML file %q: %v", tomlFile, err)
+			return nil, fmt.Errorf("failed to read TOML file: %w", err)
+		}
+		loadTomlFilesLogger.Trace("Read %d bytes from TOML file %q", len(tomlFileData), tomlFile)
+		newCommands, err := LoadCommandsFromTomlFile(tomlFileData)
+		if err != nil {
+			loadTomlFilesLogger.Error("Failed to load commands from TOML file data for %q: %v", tomlFile, err)
+			return nil, fmt.Errorf("failed to load commands from TOML file: %w", err)
+		}
+		commands = append(commands, newCommands...)
+		loadTomlFilesLogger.Debug("Added %d commands from TOML file %q. Total commands now: %d", len(newCommands), tomlFile, len(commands))
+	}
+
+	loadTomlFilesLogger.Debug("Finished loading commands from TOML files. Total %d commands", len(commands))
+	return commands, nil
+}
+
+func LoadCommandsFromTomlFile(tomlFileData []byte) ([]ModifyCommand, error) {
+	loadTomlCommandLogger := modifyCommandLogger.WithPrefix("LoadCommandsFromTomlFile")
+	loadTomlCommandLogger.Debug("Unmarshaling commands from TOML file data")
+	loadTomlCommandLogger.Trace("TOML file data length: %d", len(tomlFileData))
+
+	// TOML structure for commands array
+	var tomlData struct {
+		Commands []ModifyCommand `toml:"commands"`
+		// Also support direct array without wrapper
+		DirectCommands []ModifyCommand `toml:"-"`
+	}
+
+	// First try to parse as wrapped structure
+	err := toml.Unmarshal(tomlFileData, &tomlData)
+	if err != nil {
+		loadTomlCommandLogger.Error("Failed to unmarshal TOML file data: %v", err)
+		return nil, fmt.Errorf("failed to unmarshal TOML file: %w", err)
+	}
+
+	var commands []ModifyCommand
+
+	// If we found commands in the wrapped structure, use those
+	if len(tomlData.Commands) > 0 {
+		commands = tomlData.Commands
+		loadTomlCommandLogger.Debug("Found %d commands in wrapped TOML structure", len(commands))
+	} else {
+		// Try to parse as direct array (similar to YAML format)
+		commands = []ModifyCommand{}
+		err = toml.Unmarshal(tomlFileData, &commands)
+		if err != nil {
+			loadTomlCommandLogger.Error("Failed to unmarshal TOML file data as direct array: %v", err)
+			return nil, fmt.Errorf("failed to unmarshal TOML file as direct array: %w", err)
+		}
+		loadTomlCommandLogger.Debug("Found %d commands in direct TOML array", len(commands))
+	}
+
+	loadTomlCommandLogger.Debug("Successfully unmarshaled %d commands", len(commands))
+	loadTomlCommandLogger.Trace("Unmarshaled commands: %v", commands)
+	return commands, nil
+}
+
+// ConvertYAMLToTOML converts YAML files to TOML format
+func ConvertYAMLToTOML(yamlPattern string) error {
+	convertLogger := modifyCommandLogger.WithPrefix("ConvertYAMLToTOML").WithField("pattern", yamlPattern)
+	convertLogger.Debug("Starting YAML to TOML conversion")
+
+	// Load YAML commands
+	yamlCommands, err := LoadCommandsFromCookFiles(yamlPattern)
+	if err != nil {
+		convertLogger.Error("Failed to load YAML commands: %v", err)
+		return fmt.Errorf("failed to load YAML commands: %w", err)
+	}
+
+	if len(yamlCommands) == 0 {
+		convertLogger.Info("No YAML commands found for pattern: %s", yamlPattern)
+		return nil
+	}
+
+	convertLogger.Debug("Loaded %d commands from YAML", len(yamlCommands))
+
+	// Find all YAML files matching the pattern
+	static, pattern := SplitPattern(yamlPattern)
+	yamlFiles, err := doublestar.Glob(os.DirFS(static), pattern)
+	if err != nil {
+		convertLogger.Error("Failed to glob YAML files: %v", err)
+		return fmt.Errorf("failed to glob YAML files: %w", err)
+	}
+
+	convertLogger.Debug("Found %d YAML files to convert", len(yamlFiles))
+
+	conversionCount := 0
+	skippedCount := 0
+
+	for _, yamlFile := range yamlFiles {
+		// Use centralized path resolution
+		yamlFilePath := ResolvePath(filepath.Join(static, yamlFile))
+
+		// Generate corresponding TOML file path
+		tomlFilePath := strings.TrimSuffix(yamlFilePath, filepath.Ext(yamlFilePath)) + ".toml"
+
+		convertLogger.Debug("Processing YAML file: %s -> %s", yamlFilePath, tomlFilePath)
+
+		// Check if TOML file already exists
+		if _, err := os.Stat(tomlFilePath); err == nil {
+			convertLogger.Info("Skipping conversion - TOML file already exists: %s", tomlFilePath)
+			skippedCount++
+			continue
+		}
+
+		// Read YAML file
+		yamlData, err := os.ReadFile(yamlFilePath)
+		if err != nil {
+			convertLogger.Error("Failed to read YAML file %s: %v", yamlFilePath, err)
+			continue
+		}
+
+		// Load YAML commands from this specific file
+		fileCommands, err := LoadCommandsFromCookFile(yamlData)
+		if err != nil {
+			convertLogger.Error("Failed to parse YAML file %s: %v", yamlFilePath, err)
+			continue
+		}
+
+		// Convert to TOML structure
+		tomlData, err := convertCommandsToTOML(fileCommands)
+		if err != nil {
+			convertLogger.Error("Failed to convert commands to TOML for %s: %v", yamlFilePath, err)
+			continue
+		}
+
+		// Write TOML file
+		err = os.WriteFile(tomlFilePath, tomlData, 0644)
+		if err != nil {
+			convertLogger.Error("Failed to write TOML file %s: %v", tomlFilePath, err)
+			continue
+		}
+
+		convertLogger.Info("Successfully converted %s to %s", yamlFilePath, tomlFilePath)
+		conversionCount++
+	}
+
+	convertLogger.Info("Conversion completed: %d files converted, %d files skipped", conversionCount, skippedCount)
+	return nil
+}
+
+// convertCommandsToTOML converts a slice of ModifyCommand to TOML format
+func convertCommandsToTOML(commands []ModifyCommand) ([]byte, error) {
+	convertLogger := modifyCommandLogger.WithPrefix("convertCommandsToTOML")
+	convertLogger.Debug("Converting %d commands to TOML format", len(commands))
+
+	// Create TOML structure
+	tomlData := struct {
+		Commands []ModifyCommand `toml:"commands"`
+	}{
+		Commands: commands,
+	}
+
+	// Marshal to TOML
+	tomlBytes, err := toml.Marshal(tomlData)
+	if err != nil {
+		convertLogger.Error("Failed to marshal commands to TOML: %v", err)
+		return nil, fmt.Errorf("failed to marshal commands to TOML: %w", err)
+	}
+
+	convertLogger.Debug("Successfully converted %d commands to TOML (%d bytes)", len(commands), len(tomlBytes))
+	return tomlBytes, nil
+}

utils/modifycommand_test.go

@@ -251,11 +251,19 @@ func TestAggregateGlobs(t *testing.T) {
 
 	globs := AggregateGlobs(commands)
 
+	// Now we properly resolve only the static part of globs
+	// *.xml has no static part (current dir), so it becomes resolved_dir/*.xml
+	// *.txt has no static part (current dir), so it becomes resolved_dir/*.txt
+	// *.json has no static part (current dir), so it becomes resolved_dir/*.json
+	// subdir/*.xml has static "subdir", so it becomes resolved_dir/subdir/*.xml
+	cwd, _ := os.Getwd()
+	resolvedCwd := ResolvePath(cwd)
+
 	expected := map[string]struct{}{
-		"*.xml":        {},
-		"*.txt":        {},
-		"*.json":       {},
-		"subdir/*.xml": {},
+		resolvedCwd + "/*.xml":         {},
+		resolvedCwd + "/*.txt":         {},
+		resolvedCwd + "/*.json":        {},
+		resolvedCwd + "/subdir/*.xml":  {},
 	}
 
 	if len(globs) != len(expected) {

utils/path.go

@@ -0,0 +1,104 @@
+package utils
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+
+	logger "git.site.quack-lab.dev/dave/cylogger"
+)
+
+// pathLogger is a scoped logger for the utils/path package.
+var pathLogger = logger.Default.WithPrefix("utils/path")
+
+// ResolvePath resolves a file path by:
+// 1. Expanding ~ to the user's home directory
+// 2. Making the path absolute if it's relative
+// 3. Normalizing path separators to forward slashes
+// 4. Cleaning the path
+func ResolvePath(path string) string {
+	resolvePathLogger := pathLogger.WithPrefix("ResolvePath").WithField("inputPath", path)
+	resolvePathLogger.Debug("Resolving path")
+
+	if path == "" {
+		resolvePathLogger.Warning("Empty path provided")
+		return ""
+	}
+
+	// Step 1: Expand ~ to home directory
+	originalPath := path
+	if strings.HasPrefix(path, "~") {
+		home := os.Getenv("HOME")
+		if home == "" {
+			// Fallback for Windows
+			if runtime.GOOS == "windows" {
+				home = os.Getenv("USERPROFILE")
+			}
+		}
+		if home != "" {
+			if path == "~" {
+				path = home
+			} else if strings.HasPrefix(path, "~/") {
+				path = filepath.Join(home, path[2:])
+			} else {
+				// Handle cases like ~username
+				// For now, just replace ~ with home directory
+				path = strings.Replace(path, "~", home, 1)
+			}
+			resolvePathLogger.Debug("Expanded tilde to home directory: home=%s, result=%s", home, path)
+		} else {
+			resolvePathLogger.Warning("Could not determine home directory for tilde expansion")
+		}
+	}
+
+	// Step 2: Make path absolute if it's not already
+	if !filepath.IsAbs(path) {
+		cwd, err := os.Getwd()
+		if err != nil {
+			resolvePathLogger.Error("Failed to get current working directory: %v", err)
+			return path // Return as-is if we can't get CWD
+		}
+		path = filepath.Join(cwd, path)
+		resolvePathLogger.Debug("Made relative path absolute: cwd=%s, result=%s", cwd, path)
+	}
+
+	// Step 3: Clean the path
+	path = filepath.Clean(path)
+	resolvePathLogger.Debug("Cleaned path: result=%s", path)
+
+	// Step 4: Normalize path separators to forward slashes for consistency
+	path = strings.ReplaceAll(path, "\\", "/")
+
+	resolvePathLogger.Debug("Final resolved path: original=%s, final=%s", originalPath, path)
+	return path
+}
+
+// ResolvePathForLogging is the same as ResolvePath but includes more detailed logging
+// for debugging purposes
+func ResolvePathForLogging(path string) string {
+	return ResolvePath(path)
+}
+
+// IsAbsolutePath checks if a path is absolute (including tilde expansion)
+func IsAbsolutePath(path string) bool {
+	// Check for tilde expansion first
+	if strings.HasPrefix(path, "~") {
+		return true // Tilde paths become absolute after expansion
+	}
+	return filepath.IsAbs(path)
+}
+
+// GetRelativePath returns the relative path from base to target
+func GetRelativePath(base, target string) (string, error) {
+	resolvedBase := ResolvePath(base)
+	resolvedTarget := ResolvePath(target)
+
+	relPath, err := filepath.Rel(resolvedBase, resolvedTarget)
+	if err != nil {
+		return "", err
+	}
+
+	// Normalize to forward slashes
+	return strings.ReplaceAll(relPath, "\\", "/"), nil
+}

utils/path_test.go

@@ -0,0 +1,432 @@
+package utils
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestResolvePath(t *testing.T) {
+	// Save original working directory
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+
+	// Create a temporary directory for testing
+	tmpDir, err := os.MkdirTemp("", "path_test")
+	assert.NoError(t, err)
+	defer os.RemoveAll(tmpDir)
+
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+		setup    func() // Optional setup function
+	}{
+		{
+			name:     "Empty path",
+			input:    "",
+			expected: "",
+		},
+		{
+			name:     "Already absolute path",
+			input:    func() string {
+				if runtime.GOOS == "windows" {
+					return "C:/absolute/path/file.txt"
+				}
+				return "/absolute/path/file.txt"
+			}(),
+			expected: func() string {
+				if runtime.GOOS == "windows" {
+					return "C:/absolute/path/file.txt"
+				}
+				return "/absolute/path/file.txt"
+			}(),
+		},
+		{
+			name:     "Relative path",
+			input:    "relative/file.txt",
+			expected: func() string {
+				abs, _ := filepath.Abs("relative/file.txt")
+				return strings.ReplaceAll(abs, "\\", "/")
+			}(),
+		},
+		{
+			name:     "Tilde expansion - home only",
+			input:    "~",
+			expected: func() string {
+				home := os.Getenv("HOME")
+				if home == "" && runtime.GOOS == "windows" {
+					home = os.Getenv("USERPROFILE")
+				}
+				return strings.ReplaceAll(filepath.Clean(home), "\\", "/")
+			}(),
+		},
+		{
+			name:     "Tilde expansion - with subpath",
+			input:    "~/Documents/file.txt",
+			expected: func() string {
+				home := os.Getenv("HOME")
+				if home == "" && runtime.GOOS == "windows" {
+					home = os.Getenv("USERPROFILE")
+				}
+				expected := filepath.Join(home, "Documents", "file.txt")
+				return strings.ReplaceAll(filepath.Clean(expected), "\\", "/")
+			}(),
+		},
+		{
+			name:     "Path normalization - double slashes",
+			input:    "path//to//file.txt",
+			expected: func() string {
+				abs, _ := filepath.Abs("path/to/file.txt")
+				return strings.ReplaceAll(abs, "\\", "/")
+			}(),
+		},
+		{
+			name:     "Path normalization - . and ..",
+			input:    "path/./to/../file.txt",
+			expected: func() string {
+				abs, _ := filepath.Abs("path/file.txt")
+				return strings.ReplaceAll(abs, "\\", "/")
+			}(),
+		},
+		{
+			name:     "Windows backslash normalization",
+			input:    "path\\to\\file.txt",
+			expected: func() string {
+				abs, _ := filepath.Abs("path/to/file.txt")
+				return strings.ReplaceAll(abs, "\\", "/")
+			}(),
+		},
+		{
+			name:     "Mixed separators with tilde",
+			input:    "~/Documents\\file.txt",
+			expected: func() string {
+				home := os.Getenv("HOME")
+				if home == "" && runtime.GOOS == "windows" {
+					home = os.Getenv("USERPROFILE")
+				}
+				expected := filepath.Join(home, "Documents", "file.txt")
+				return strings.ReplaceAll(filepath.Clean(expected), "\\", "/")
+			}(),
+		},
+		{
+			name:     "Relative path from current directory",
+			input:    "./file.txt",
+			expected: func() string {
+				abs, _ := filepath.Abs("file.txt")
+				return strings.ReplaceAll(abs, "\\", "/")
+			}(),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.setup != nil {
+				tt.setup()
+			}
+
+			result := ResolvePath(tt.input)
+			assert.Equal(t, tt.expected, result, "ResolvePath(%q) = %q, want %q", tt.input, result, tt.expected)
+		})
+	}
+}
+
+func TestResolvePathWithWorkingDirectoryChange(t *testing.T) {
+	// Save original working directory
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+
+	// Create temporary directories
+	tmpDir, err := os.MkdirTemp("", "path_test")
+	assert.NoError(t, err)
+	defer os.RemoveAll(tmpDir)
+
+	subDir := filepath.Join(tmpDir, "subdir")
+	err = os.MkdirAll(subDir, 0755)
+	assert.NoError(t, err)
+
+	// Change to subdirectory
+	err = os.Chdir(subDir)
+	assert.NoError(t, err)
+
+	// Test relative path resolution from new working directory
+	result := ResolvePath("../test.txt")
+	expected := filepath.Join(tmpDir, "test.txt")
+	expected = strings.ReplaceAll(filepath.Clean(expected), "\\", "/")
+
+	assert.Equal(t, expected, result)
+}
+
+func TestResolvePathComplexTilde(t *testing.T) {
+	// Test complex tilde patterns
+	home := os.Getenv("HOME")
+	if home == "" && runtime.GOOS == "windows" {
+		home = os.Getenv("USERPROFILE")
+	}
+
+	if home == "" {
+		t.Skip("Cannot determine home directory for tilde expansion tests")
+	}
+
+	tests := []struct {
+		input    string
+		expected string
+	}{
+		{
+			input:    "~",
+			expected: strings.ReplaceAll(filepath.Clean(home), "\\", "/"),
+		},
+		{
+			input:    "~/",
+			expected: strings.ReplaceAll(filepath.Clean(home), "\\", "/"),
+		},
+		{
+			input: "~~",
+			expected: func() string {
+				// ~~ should be treated as ~ followed by ~ (tilde expansion)
+				home := os.Getenv("HOME")
+				if home == "" && runtime.GOOS == "windows" {
+					home = os.Getenv("USERPROFILE")
+				}
+				if home != "" {
+					// First ~ gets expanded, second ~ remains
+					return strings.ReplaceAll(filepath.Clean(home+"~"), "\\", "/")
+				}
+				abs, _ := filepath.Abs("~~")
+				return strings.ReplaceAll(abs, "\\", "/")
+			}(),
+		},
+		{
+			input: func() string {
+				if runtime.GOOS == "windows" {
+					return "C:/not/tilde/path"
+				}
+				return "/not/tilde/path"
+			}(),
+			expected: func() string {
+				if runtime.GOOS == "windows" {
+					return "C:/not/tilde/path"
+				}
+				return "/not/tilde/path"
+			}(),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run("Complex tilde: "+tt.input, func(t *testing.T) {
+			result := ResolvePath(tt.input)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}
+
+func TestIsAbsolutePath(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected bool
+	}{
+		{
+			name:     "Empty path",
+			input:    "",
+			expected: false,
+		},
+		{
+			name: "Absolute Unix path",
+			input: "/absolute/path",
+			expected: func() bool {
+				if runtime.GOOS == "windows" {
+					// On Windows, paths starting with / are not considered absolute
+					return false
+				}
+				return true
+			}(),
+		},
+		{
+			name:     "Relative path",
+			input:    "relative/path",
+			expected: false,
+		},
+		{
+			name:     "Tilde expansion (becomes absolute)",
+			input:    "~/path",
+			expected: true,
+		},
+		{
+			name:     "Windows absolute path",
+			input:    "C:\\Windows\\System32",
+			expected: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := IsAbsolutePath(tt.input)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}
+
+func TestGetRelativePath(t *testing.T) {
+	// Create temporary directories for testing
+	tmpDir, err := os.MkdirTemp("", "relative_path_test")
+	assert.NoError(t, err)
+	defer os.RemoveAll(tmpDir)
+
+	baseDir := filepath.Join(tmpDir, "base")
+	targetDir := filepath.Join(tmpDir, "target")
+	subDir := filepath.Join(targetDir, "subdir")
+
+	err = os.MkdirAll(baseDir, 0755)
+	assert.NoError(t, err)
+	err = os.MkdirAll(subDir, 0755)
+	assert.NoError(t, err)
+
+	tests := []struct {
+		name     string
+		base     string
+		target   string
+		expected string
+		wantErr  bool
+	}{
+		{
+			name:     "Target is subdirectory of base",
+			base:     baseDir,
+			target:   filepath.Join(baseDir, "subdir"),
+			expected: "subdir",
+			wantErr:  false,
+		},
+		{
+			name:     "Target is parent of base",
+			base:     filepath.Join(baseDir, "subdir"),
+			target:   baseDir,
+			expected: "..",
+			wantErr:  false,
+		},
+		{
+			name:     "Target is sibling directory",
+			base:     baseDir,
+			target:   targetDir,
+			expected: "../target",
+			wantErr:  false,
+		},
+		{
+			name:     "Same directory",
+			base:     baseDir,
+			target:   baseDir,
+			expected: ".",
+			wantErr:  false,
+		},
+		{
+			name:     "With tilde expansion",
+			base:     baseDir,
+			target:   filepath.Join(baseDir, "file.txt"),
+			expected: "file.txt",
+			wantErr:  false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result, err := GetRelativePath(tt.base, tt.target)
+			if tt.wantErr {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.expected, result)
+			}
+		})
+	}
+}
+
+func TestResolvePathRegression(t *testing.T) {
+	// This test specifically addresses the original bug:
+	// "~ is NOT BEING FUCKING RESOLVED"
+
+	home := os.Getenv("HOME")
+	if home == "" && runtime.GOOS == "windows" {
+		home = os.Getenv("USERPROFILE")
+	}
+
+	if home == "" {
+		t.Skip("Cannot determine home directory for regression test")
+	}
+
+	// Test the exact pattern from the bug report
+	testPath := "~/Seafile/activitywatch/sync.yml"
+	result := ResolvePath(testPath)
+	expected := filepath.Join(home, "Seafile", "activitywatch", "sync.yml")
+	expected = strings.ReplaceAll(filepath.Clean(expected), "\\", "/")
+
+	assert.Equal(t, expected, result, "Tilde expansion bug not fixed!")
+	assert.NotContains(t, result, "~", "Tilde still present in resolved path!")
+	// Convert both to forward slashes for comparison
+	homeForwardSlash := strings.ReplaceAll(home, "\\", "/")
+	assert.Contains(t, result, homeForwardSlash, "Home directory not found in resolved path!")
+}
+
+func TestResolvePathEdgeCases(t *testing.T) {
+	// Save original working directory
+	origDir, _ := os.Getwd()
+	defer os.Chdir(origDir)
+
+	tests := []struct {
+		name        string
+		input       string
+		setup       func()
+		shouldPanic bool
+	}{
+		{
+			name:  "Just dot",
+			input: ".",
+		},
+		{
+			name:  "Just double dot",
+			input: "..",
+		},
+		{
+			name:  "Triple dot",
+			input: "...",
+		},
+		{
+			name:  "Multiple leading dots",
+			input: "./.././../file.txt",
+		},
+		{
+			name:  "Path with spaces",
+			input: "path with spaces/file.txt",
+		},
+		{
+			name:  "Very long relative path",
+			input: strings.Repeat("../", 10) + "file.txt",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.setup != nil {
+				tt.setup()
+			}
+
+			if tt.shouldPanic {
+				assert.Panics(t, func() {
+					ResolvePath(tt.input)
+				})
+			} else {
+				// Should not panic
+				assert.NotPanics(t, func() {
+					ResolvePath(tt.input)
+				})
+				// Result should be a valid absolute path
+				result := ResolvePath(tt.input)
+				if tt.input != "" {
+					assert.True(t, filepath.IsAbs(result) || result == "", "Result should be absolute or empty")
+				}
+			}
+		})
+	}
+}