Add comprehensive tests for XML parser functionality

- Introduced benchmark tests for various XML parsing methods, including parsing from strings, bytes, and readers, to evaluate performance.
- Added unit tests for the parser interface and validation mechanisms, ensuring robust error handling and validation logic.
- Implemented tests for utility functions related to XML processing, enhancing overall test coverage and reliability.
- Created a test suite for the TED domain, validating the structure and functionality of contract notices and related entities.
- Developed a comprehensive test runner script to facilitate automated testing, coverage analysis, and performance benchmarking for the XML parser package.

pkg/xmlparser/parser.go

@@ -61,6 +61,13 @@ func (p *GenericParser[T]) ParseBytes(xmlData []byte) (*T, error) {
 		targetPtr = reflect.New(resultType).Interface()
 	}
 
+	// Check depth limit before parsing if specified
+	if p.options.MaxDepth > 0 {
+		if err := p.checkDepthLimit(xmlData); err != nil {
+			return nil, err
+		}
+	}
+
 	// Create XML decoder
 	decoder := xml.NewDecoder(bytes.NewReader(xmlData))
 
@@ -142,6 +149,38 @@ func (p *GenericParser[T]) Validate(reader io.Reader) error {
 	return nil
 }
 
+// checkDepthLimit validates that XML doesn't exceed the maximum depth limit
+func (p *GenericParser[T]) checkDepthLimit(xmlData []byte) error {
+	decoder := xml.NewDecoder(bytes.NewReader(xmlData))
+	depth := 0
+	maxDepthReached := 0
+
+	for {
+		token, err := decoder.Token()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return fmt.Errorf("XML depth validation failed: %w", err)
+		}
+
+		switch token.(type) {
+		case xml.StartElement:
+			depth++
+			if depth > maxDepthReached {
+				maxDepthReached = depth
+			}
+			if depth > p.options.MaxDepth {
+				return fmt.Errorf("XML depth %d exceeds maximum allowed depth %d", depth, p.options.MaxDepth)
+			}
+		case xml.EndElement:
+			depth--
+		}
+	}
+
+	return nil
+}
+
 // ParseWithResult parses XML and returns detailed result with metadata
 func (p *GenericParser[T]) ParseWithResult(reader io.Reader) (*ParseResult[T], error) {
 	result := &ParseResult[T]{