Merge pull request #24 from m-mizutani/fix/json-unmarshal-type-error

fix(clone): Ignore `reflect.rtype`

clone.go

@@ -12,6 +12,13 @@ const (
 	maxDepth = 32
 )
 
+var (
+	// ignoreTypes is a map of types that should not be redacted. It lists types that can not be copied. For example, reflect.Type is a pointer to a struct and copying it causes panic. Especially, reflect.rtype is unexported type. Then, the ignoreTypes is list of string of type name.
+	ignoreTypes = map[string]struct{}{
+		"*reflect.rtype": {},
+	}
+)
+
 func (x *masq) clone(ctx context.Context, fieldName string, src reflect.Value, tag string) reflect.Value {
 	if v, ok := ctx.Value(ctxKeyDepth{}).(int); !ok {
 		ctx = context.WithValue(ctx, ctxKeyDepth{}, 0)
@@ -26,6 +33,9 @@ func (x *masq) clone(ctx context.Context, fieldName string, src reflect.Value, t
 	if _, ok := x.allowedTypes[src.Type()]; ok {
 		return src
 	}
+	if _, ok := ignoreTypes[src.Type().String()]; ok {
+		return src
+	}
 
 	if src.Kind() == reflect.Ptr && src.IsNil() {
 		return reflect.New(src.Type()).Elem()

clone_test.go

@@ -343,3 +343,21 @@ func TestCircularReference(t *testing.T) {
 	newData := c.Redact(data).(*myStruct)
 	gt.V(t, newData.Child.Child.Str).Equal("[REDACTED]")
 }
+
+func TestCloneFunc(t *testing.T) {
+	type myFunc func() string
+	src := myFunc(func() string { return "blue" })
+	dst := masq.NewMasq().Redact(src).(myFunc)
+	gt.Equal(t, dst(), "blue")
+}
+
+func TestUnmarshalTypeError(t *testing.T) {
+	var buf bytes.Buffer
+	logger := slog.New(slog.NewJSONHandler(&buf, &slog.HandlerOptions{
+		ReplaceAttr: masq.New(),
+	}))
+	var s string
+	err := json.Unmarshal([]byte(`["foo"]`), &s)
+	logger.Info("error", slog.Any("err", err))
+	gt.S(t, buf.String()).Contains("error")
+}