Move all summary logic out of main into filesystem.go

filesystem.go

@@ -3,6 +3,8 @@ package main
 import (
 	"fmt"
 	"os"
+	"sort"
+	"strings"
 	"sync"
 )
 
@@ -17,6 +19,7 @@ type FileSystem interface {
 	Link(source, target string) error
 	RecordLinkAttempt(kind string, source, target string, err error, dryRun bool)
 	SummaryLines() []string
+	SummaryRecords() []operationRecord
 	IsDryRun() bool
 }
 
@@ -37,26 +40,96 @@ type operationRecord struct {
 }
 
 func (r operationRecord) summaryLine() (string, bool) {
-	if r.kind != opSymlink && r.kind != opHardlink {
-		return "", false
+	detail := r.detail()
+	if detail != "" {
+		return fmt.Sprintf("%s %s → %s (%s) %s",
+			r.kindLabel(),
+			r.formattedSource(),
+			r.formattedTarget(),
+			r.resultLabel(),
+			detail), true
 	}
 
-	kindLabel := "Symlink"
-	if r.kind == opHardlink {
-		kindLabel = "Hardlink"
-	}
+	return fmt.Sprintf("%s %s → %s (%s)",
+		r.kindLabel(),
+		r.formattedSource(),
+		r.formattedTarget(),
+		r.resultLabel()), true
+}
 
-	status := "OK"
+func (r operationRecord) kindLabel() string {
+	switch r.kind {
+	case opSymlink:
+		return "Symlink"
+	case opHardlink:
+		return "Hardlink"
+	case opRemove:
+		return "Remove"
+	case opRemoveAll:
+		return "RemoveAll"
+	case opMkdirAll:
+		return "MkdirAll"
+	default:
+		return r.kind
+	}
+}
+
+func (r operationRecord) resultLabel() string {
 	if r.err != nil {
-		status = fmt.Sprintf("FAIL: %v", r.err)
-	} else if r.dryRun {
-		status = "DRY-RUN"
+		return fmt.Sprintf("%sFAIL%s", BRed, Reset)
 	}
+	if r.dryRun {
+		return fmt.Sprintf("%sDRY-RUN%s", BCyan, Reset)
+	}
+	return fmt.Sprintf("%sOK%s", BGreen, Reset)
+}
 
-	source := FormatSourcePath(r.source)
-	target := FormatTargetPath(r.target)
+func (r operationRecord) resultLabelPlain() string {
+	if r.err != nil {
+		return "FAIL"
+	}
+	if r.dryRun {
+		return "DRY-RUN"
+	}
+	return "OK"
+}
 
-	return fmt.Sprintf("%s %s → %s (%s)", kindLabel, source, target, status), true
+func (r operationRecord) formattedSource() string {
+	if r.source == "" {
+		return "-"
+	}
+	return FormatSourcePath(r.source)
+}
+
+func (r operationRecord) plainSource() string {
+	if r.source == "" {
+		return "-"
+	}
+	return r.source
+}
+
+func (r operationRecord) formattedTarget() string {
+	if r.target == "" {
+		return "-"
+	}
+	return FormatTargetPath(r.target)
+}
+
+func (r operationRecord) plainTarget() string {
+	if r.target == "" {
+		return "-"
+	}
+	return r.target
+}
+
+func (r operationRecord) detail() string {
+	if r.err != nil {
+		return r.err.Error()
+	}
+	if r.dryRun {
+		return "dry-run"
+	}
+	return ""
 }
 
 type baseFileSystem struct {
@@ -141,6 +214,10 @@ func (fs *realFileSystem) SummaryLines() []string {
 	return summarizeOperations(fs.snapshot())
 }
 
+func (fs *realFileSystem) SummaryRecords() []operationRecord {
+	return fs.snapshot()
+}
+
 func (fs *realFileSystem) IsDryRun() bool {
 	return false
 }
@@ -187,6 +264,132 @@ func (fs *dryRunFileSystem) SummaryLines() []string {
 	return summarizeOperations(fs.snapshot())
 }
 
+func (fs *dryRunFileSystem) SummaryRecords() []operationRecord {
+	return fs.snapshot()
+}
+
 func (fs *dryRunFileSystem) IsDryRun() bool {
 	return true
 }
+
+func BuildSummaryLines(records []operationRecord) []string {
+	if len(records) == 0 {
+		return nil
+	}
+
+	sorted := make([]operationRecord, len(records))
+	copy(sorted, records)
+
+	opOrder := map[string]int{
+		opRemove:    0,
+		opRemoveAll: 1,
+		opMkdirAll:  2,
+		opSymlink:   3,
+		opHardlink:  4,
+	}
+
+	sort.SliceStable(sorted, func(i, j int) bool {
+		ti := strings.ToLower(sorted[i].plainTarget())
+		tj := strings.ToLower(sorted[j].plainTarget())
+		if ti != tj {
+			return ti < tj
+		}
+
+		si := strings.ToLower(sorted[i].plainSource())
+		sj := strings.ToLower(sorted[j].plainSource())
+		if si != sj {
+			return si < sj
+		}
+
+		oi := opOrderValue(sorted[i].kind, opOrder)
+		oj := opOrderValue(sorted[j].kind, opOrder)
+		if oi != oj {
+			return oi < oj
+		}
+
+		return sorted[i].detail() < sorted[j].detail()
+	})
+
+	header := []string{"RESULT", "OPERATION", "SOURCE", "TARGET", "DETAIL"}
+	widths := make([]int, len(header))
+	for i, h := range header {
+		widths[i] = len(h)
+	}
+
+	plainRows := make([][]string, len(sorted))
+	coloredRows := make([][]string, len(sorted))
+	for i, record := range sorted {
+		detail := record.detail()
+		if detail == "" {
+			detail = "-"
+		}
+
+		plain := []string{
+			record.resultLabelPlain(),
+			record.kindLabel(),
+			record.plainSource(),
+			record.plainTarget(),
+			detail,
+		}
+		colored := []string{
+			record.resultLabel(),
+			record.kindLabel(),
+			record.formattedSource(),
+			record.formattedTarget(),
+			detail,
+		}
+
+		plainRows[i] = plain
+		coloredRows[i] = colored
+
+		for j, val := range plain {
+			if val == "" {
+				val = "-"
+			}
+			if len(val) > widths[j] {
+				widths[j] = len(val)
+			}
+		}
+	}
+
+	lines := make([]string, 0, len(sorted)+1)
+	lines = append(lines, formatSummaryRow(header, header, widths))
+	for i := range coloredRows {
+		lines = append(lines, formatSummaryRow(coloredRows[i], plainRows[i], widths))
+	}
+
+	return lines
+}
+
+func formatSummaryRow(colored, plain []string, widths []int) string {
+	var b strings.Builder
+	for i := range colored {
+		p := plain[i]
+		if p == "" {
+			p = "-"
+		}
+		col := colored[i]
+		if col == "" {
+			col = p
+		}
+		pad := widths[i] - len(p)
+		if pad < 0 {
+			pad = 0
+		}
+		b.WriteString(col)
+		if pad > 0 {
+			b.WriteString(strings.Repeat(" ", pad))
+		}
+		if i < len(colored)-1 {
+			b.WriteString("  ")
+		}
+	}
+	return b.String()
+}
+
+func opOrderValue(kind string, order map[string]int) int {
+	if v, ok := order[kind]; ok {
+		return v
+	}
+	return len(order)
+}

filesystem_test.go

@@ -0,0 +1,19 @@
+package main
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSummaryLineMarksFailuresInRed(t *testing.T) {
+	fs := NewRealFileSystem()
+
+	fs.RecordLinkAttempt(opSymlink, "/tmp/source", "/tmp/target", fmt.Errorf("boom"), false)
+
+	lines := fs.SummaryLines()
+	assert.Equal(t, 1, len(lines))
+	assert.Contains(t, lines[0], BRed+"FAIL"+Reset)
+	assert.Contains(t, lines[0], "boom")
+}

main.go

@@ -185,10 +185,7 @@ func processInstructions(instructions chan *LinkInstruction) int32 {
 }
 
 func printSummary(fs FileSystem) {
-	lines := fs.SummaryLines()
-	if len(lines) == 0 {
-		return
-	}
+	lines := BuildSummaryLines(fs.SummaryRecords())
 	LogInfo("Summary:")
 	for _, line := range lines {
 		LogInfo("%s", line)