feat: simplify rules for receiver with type parameters

Fix #38

Signed-off-by: Timon Wong <[email protected]>

internal/rules/rules.go

@@ -45,6 +45,52 @@ func (rs *Ruleset) Match(fn *types.Func) bool {
 
 func emptyQualifier(*types.Package) string { return "" }
 
+func receiverTypeOf(recvType types.Type) string {
+	buf := bytebufferpool.Get()
+	defer bytebufferpool.Put(buf)
+
+	var recvElemType *types.Named
+	switch recvType := recvType.(type) {
+	case *types.Pointer:
+		buf.WriteByte('*')
+		if elem, ok := recvType.Elem().(*types.Named); ok {
+			recvElemType = elem
+		}
+	case *types.Named:
+		recvElemType = recvType
+	}
+
+	if recvElemType == nil {
+		buf.Reset() // Reset in case we have modifications
+		types.WriteType(buf, recvType, emptyQualifier)
+		return buf.String()
+	}
+
+	buf.WriteString(recvElemType.Obj().Name())
+	typeParams := recvElemType.TypeParams()
+	typeParamsLen := typeParams.Len()
+
+	if typeParamsLen > 0 {
+		buf.WriteByte('[')
+		for i := 0; i < typeParamsLen; i++ {
+			if i > 0 {
+				// comma as separator
+				buf.WriteByte(',')
+			}
+			p := typeParams.At(i)
+			if p == nil {
+				// Just in case
+				buf.WriteString("nil")
+				continue
+			}
+			buf.WriteString(p.Obj().Name())
+		}
+		buf.WriteByte(']')
+	}
+
+	return buf.String()
+}
+
 func matchRule(p *FuncRule, sig *types.Signature) bool {
 	// we do not check package import here since it's already checked in Match()
 	recv := sig.Recv()
@@ -55,10 +101,8 @@ func matchRule(p *FuncRule, sig *types.Signature) bool {
 
 	if isReceiver {
 		recvType := recv.Type()
-		recvTypeBuf := bytebufferpool.Get()
-		defer bytebufferpool.Put(recvTypeBuf)
-		types.WriteType(recvTypeBuf, recvType, emptyQualifier)
-		if recvTypeBuf.String() != p.ReceiverType {
+		receiverType := receiverTypeOf(recvType)
+		if receiverType != p.ReceiverType {
 			return false
 		}
 	}

testdata/custom-rules-generic.txt

@@ -1,2 +1,2 @@
 # Generic methods
-(*a/custom-generic.Logger[any]).Infow
+(*a/custom-generic.Logger[T,W]).Infow

testdata/src/a/custom-generic/example.go

@@ -2,17 +2,28 @@ package custom_generic
 
 import "go.uber.org/zap"
 
-type Logger[T any] struct {
+type Signed interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64
+}
+
+type Unsigned interface {
+	~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr
+}
+
+type Integer interface {
+	Signed | Unsigned
+}
+type Logger[T, W Integer] struct {
 	*zap.SugaredLogger
 }
 
-func (l *Logger[T]) Infow(message string, keysAndValues ...any) {
+func (l *Logger[T, W]) Infow(message string, keysAndValues ...any) {
 	l.SugaredLogger.Infow(message, keysAndValues...)
 }
 
 func ExampleGenericCustomOnly() {
 	l := zap.NewExample().Sugar()
-	logger := &Logger[any]{l}
+	logger := &Logger[int8, int]{l}
 
 	logger.Infow("custom message", "hello")                                     // want `odd number of arguments passed as key-value pairs for logging`
 	logger.Debugw("embedded sugar log also works without custom rules", "key1") // want `odd number of arguments passed as key-value pairs for logging`