Add xpath tests

processor/xpath/xpath.go

@@ -0,0 +1,98 @@
+package xpath
+
+import "errors"
+
+// XPathStep represents a single step in an XPath expression
+type XPathStep struct {
+	Type      StepType
+	Name      string
+	Predicate *Predicate
+}
+
+// StepType defines the type of XPath step
+type StepType int
+
+const (
+	// RootStep represents the root step (/)
+	RootStep StepType = iota
+	// ChildStep represents a child element step (element)
+	ChildStep
+	// RecursiveDescentStep represents a recursive descent step (//)
+	RecursiveDescentStep
+	// WildcardStep represents a wildcard step (*)
+	WildcardStep
+	// PredicateStep represents a predicate condition step ([...])
+	PredicateStep
+)
+
+// PredicateType defines the type of XPath predicate
+type PredicateType int
+
+const (
+	// IndexPredicate represents an index predicate [n]
+	IndexPredicate PredicateType = iota
+	// LastPredicate represents a last() function predicate
+	LastPredicate
+	// LastMinusPredicate represents a last()-n predicate
+	LastMinusPredicate
+	// PositionPredicate represents position()-based predicates
+	PositionPredicate
+	// AttributeExistsPredicate represents [@attr] predicate
+	AttributeExistsPredicate
+	// AttributeEqualsPredicate represents [@attr='value'] predicate
+	AttributeEqualsPredicate
+	// ComparisonPredicate represents element comparison predicates
+	ComparisonPredicate
+)
+
+// Predicate represents a condition in XPath
+type Predicate struct {
+	Type       PredicateType
+	Index      int
+	Offset     int
+	Attribute  string
+	Value      string
+	Expression string
+}
+
+// XMLNode represents a node in the result set with its value and path
+type XMLNode struct {
+	Value interface{}
+	Path  string
+}
+
+// ParseXPath parses an XPath expression into a series of steps
+func ParseXPath(path string) ([]XPathStep, error) {
+	if path == "" {
+		return nil, errors.New("empty path")
+	}
+
+	// This is just a placeholder implementation for the tests
+	// The actual implementation would parse the XPath expression
+	return nil, errors.New("not implemented")
+}
+
+// Get retrieves nodes from XML data using an XPath expression
+func Get(data interface{}, path string) ([]XMLNode, error) {
+	if data == "" {
+		return nil, errors.New("empty XML data")
+	}
+
+	// This is just a placeholder implementation for the tests
+	// The actual implementation would evaluate the XPath against the XML
+	return nil, errors.New("not implemented")
+}
+
+// Set updates a node in the XML data using an XPath expression
+func Set(xmlData string, path string, value interface{}) (string, error) {
+	// This is just a placeholder implementation for the tests
+	// The actual implementation would modify the XML based on the XPath
+	return "", errors.New("not implemented")
+}
+
+// SetAll updates all nodes matching an XPath expression in the XML data
+func SetAll(xmlData string, path string, value interface{}) (string, error) {
+	// This is just a placeholder implementation for the tests
+	// The actual implementation would modify all matching nodes
+	return "", errors.New("not implemented")
+}