fix: refactor + improve metrics

Author: amanv8060

analyzer/analyzer.go

@@ -0,0 +1,97 @@
+package analyzer
+
+import (
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"math"
+)
+
+// FileAnalyzer represents a file analyzer.
+type FileAnalyzer struct {
+	fset *token.FileSet
+	ast  *ast.File
+}
+
+func NewFileAnalyzer(filename string, content []byte) (*FileAnalyzer, error) {
+	fset := token.NewFileSet()
+	node, err := parser.ParseFile(fset, filename, content, parser.ParseComments)
+	if err != nil {
+		return nil, err
+	}
+
+	return &FileAnalyzer{
+		fset: fset,
+		ast:  node,
+	}, nil
+}
+
+// AnalyzeFunction analyzes a function declaration and returns the metrics.
+func (fa *FileAnalyzer) AnalyzeFunction(funcDecl *ast.FuncDecl) *MetricsResult {
+	if funcDecl == nil || funcDecl.Name == nil {
+		return nil
+	}
+
+	cyclomaticComplexity := fa.CalculateCyclomaticComplexity(funcDecl)
+	cognitiveComplexity := fa.CalculateCognitiveComplexity(funcDecl)
+	linesOfCode := fa.CountLinesOfCode(funcDecl)
+	volume, difficulty, effort := fa.calculateHalsteadMetrics(funcDecl)
+	maintainabilityIndex := fa.CalculateMaintainabilityIndex(cyclomaticComplexity, volume, linesOfCode)
+	nestedDepth := fa.calculateNestedDepth(funcDecl)
+	commentDensity := fa.calculateCommentDensity(funcDecl)
+	paramCount := 0
+	if funcDecl.Type.Params != nil {
+		for _, field := range funcDecl.Type.Params.List {
+			paramCount += len(field.Names)
+		}
+	}
+	returnCount := fa.countReturnStatements(funcDecl)
+
+	if math.IsNaN(volume) || math.IsInf(volume, 0) {
+		volume = 0
+	}
+	if math.IsNaN(difficulty) || math.IsInf(difficulty, 0) {
+		difficulty = 0
+	}
+	if math.IsNaN(effort) || math.IsInf(effort, 0) {
+		effort = 0
+	}
+	if math.IsNaN(maintainabilityIndex) || math.IsInf(maintainabilityIndex, 0) {
+		maintainabilityIndex = 0
+	}
+	if math.IsNaN(commentDensity) || math.IsInf(commentDensity, 0) {
+		commentDensity = 0
+	}
+
+	return &MetricsResult{
+		Name:                 funcDecl.Name.Name,
+		CyclomaticComplexity: cyclomaticComplexity,
+		CognitiveComplexity:  cognitiveComplexity,
+		LinesOfCode:          linesOfCode,
+		HalsteadVolume:       math.Round(volume*100) / 100,
+		HalsteadDifficulty:   math.Round(difficulty*100) / 100,
+		HalsteadEffort:       math.Round(effort*100) / 100,
+		MaintainabilityIndex: math.Round(maintainabilityIndex*100) / 100,
+		NestedDepth:          nestedDepth,
+		CommentDensity:       math.Round(commentDensity*100) / 100,
+		FunctionParameters:   paramCount,
+		ReturnStatements:     returnCount,
+	}
+}
+
+// AnalyzeFile analyzes a file and returns the metrics for each function.
+func (fa *FileAnalyzer) AnalyzeFile() []*MetricsResult {
+	var results []*MetricsResult
+
+	ast.Inspect(fa.ast, func(n ast.Node) bool {
+		if funcDecl, ok := n.(*ast.FuncDecl); ok {
+			result := fa.AnalyzeFunction(funcDecl)
+			if result != nil {
+				results = append(results, result)
+			}
+		}
+		return true
+	})
+
+	return results
+}