gracefully handle anonymous structs

testdata.go

@@ -114,7 +114,7 @@ func assert(log *logger, dir string, values ...any) error {
 		}
 
 		if !cmp.Equal(expected, actual) {
-			return fmt.Errorf("test of %T failed: %s", expected, cmp.Diff(expected, actual))
+			return fmt.Errorf("test of %s failed: %s", getTypeName(expected), cmp.Diff(expected, actual))
 		}
 	}
 
@@ -131,7 +131,7 @@ func loadDirs(log *logger, inputs []string, outputs ...any) error {
 			return errors.New("output cannot be nil")
 		}
 
-		vlog := log.WithPrefix(fmt.Sprintf("%T", output))
+		vlog := log.WithPrefix(getTypeName(output))
 
 		if err := loadDir(vlog, inputs, output); err != nil {
 			return err
@@ -155,7 +155,7 @@ func loadDir(log *logger, inputs []string, output any) error {
 
 		tags, err := structtag.Parse(string(field.Tag))
 		if err != nil {
-			return fmt.Errorf("%T.%s: failed to parse struct tags: %w", output, field.Name, err)
+			return fmt.Errorf("%s.%s: failed to parse struct tags: %w", getTypeName(output), field.Name, err)
 		}
 
 		tag, err := tags.Get(tagName)
@@ -167,7 +167,7 @@ func loadDir(log *logger, inputs []string, output any) error {
 
 		for _, input := range inputs {
 			if err := loadDirInput(log, input, tag, field, value); err != nil {
-				return fmt.Errorf("%T.%s: %w", output, field.Name, err)
+				return fmt.Errorf("%s.%s: %w", getTypeName(output), field.Name, err)
 			}
 		}
 	}
@@ -277,7 +277,7 @@ func saveDir(log *logger, dir string, input any) error {
 
 		tags, err := structtag.Parse(string(field.Tag))
 		if err != nil {
-			return fmt.Errorf("%T.%s: failed to parse struct tags: %w", input, field.Name, err)
+			return fmt.Errorf("%s.%s: failed to parse struct tags: %w", getTypeName(input), field.Name, err)
 		}
 
 		tag, err := tags.Get(tagName)
@@ -287,8 +287,8 @@ func saveDir(log *logger, dir string, input any) error {
 			continue
 		}
 
-		if err := saveDirField(log.WithPrefix("."+field.Name), dir, tag, field, value); err != nil {
-			return fmt.Errorf("%T.%s error: %w", input, field.Name, err)
+		if err := saveDirField(log.WithPrefix(fmt.Sprintf("%s.%s", getTypeName(input), field.Name)), dir, tag, field, value); err != nil {
+			return fmt.Errorf("%s.%s error: %w", getTypeName(input), field.Name, err)
 		}
 	}
 
@@ -394,3 +394,13 @@ func isBytes(targetType reflect.Type) bool {
 func isMap(targetType reflect.Type) bool {
 	return targetType.Kind() == reflect.Map && isString(targetType.Key())
 }
+
+func getTypeName(input any) string {
+	t := reflect.TypeOf(input)
+
+	if t.Kind() == reflect.Ptr && t.Elem().PkgPath() == "" {
+		return "<anonymous>"
+	} else {
+		return t.String()
+	}
+}

testdata_test.go

@@ -414,7 +414,7 @@ func TestAssert(t *testing.T) {
 					Input: "hello world",
 				},
 				logs: []string{
-					`[GoT] Assert: .Input: saved file "<tmp>/input.txt" (size 11)`,
+					`[GoT] Assert: <anonymous>.Input: saved file "<tmp>/input.txt" (size 11)`,
 				},
 			},
 			{
@@ -425,7 +425,7 @@ func TestAssert(t *testing.T) {
 					Input: []byte("hello world"),
 				},
 				logs: []string{
-					`[GoT] Assert: .Input: saved file "<tmp>/input.txt" (size 11)`,
+					`[GoT] Assert: <anonymous>.Input: saved file "<tmp>/input.txt" (size 11)`,
 				},
 			},
 			{
@@ -436,7 +436,7 @@ func TestAssert(t *testing.T) {
 					Input: json.RawMessage(`{}`),
 				},
 				logs: []string{
-					`[GoT] Assert: .Input: saved file "<tmp>/input.json" (size 2)`,
+					`[GoT] Assert: <anonymous>.Input: saved file "<tmp>/input.json" (size 2)`,
 				},
 			},
 			{
@@ -453,7 +453,7 @@ func TestAssert(t *testing.T) {
 					},
 				},
 				logs: []string{
-					`[GoT] Assert: .Input: saved file "<tmp>/input.json" (size 22)`,
+					`[GoT] Assert: <anonymous>.Input: saved file "<tmp>/input.json" (size 22)`,
 				},
 			},
 			{
@@ -464,7 +464,7 @@ func TestAssert(t *testing.T) {
 					Input: map[string]string{"hello": "world"},
 				},
 				logs: []string{
-					`[GoT] Assert: .Input: saved file "<tmp>/input.json" (size 22)`,
+					`[GoT] Assert: <anonymous>.Input: saved file "<tmp>/input.json" (size 22)`,
 				},
 			},
 			{
@@ -475,8 +475,8 @@ func TestAssert(t *testing.T) {
 					Files: map[string]string{"a.txt": "A", "b.txt": "B"},
 				},
 				logs: []string{
-					`[GoT] Assert: .Files: saved file "<tmp>/a.txt" (size 1)`,
-					`[GoT] Assert: .Files: saved file "<tmp>/b.txt" (size 1)`,
+					`[GoT] Assert: <anonymous>.Files: saved file "<tmp>/a.txt" (size 1)`,
+					`[GoT] Assert: <anonymous>.Files: saved file "<tmp>/b.txt" (size 1)`,
 				},
 			},
 			{
@@ -501,7 +501,7 @@ func TestAssert(t *testing.T) {
 					Empty  string `testdata:"-"`
 				}{},
 				logs: []string{
-					`[GoT] Assert: .Output: removed file "<tmp>/output.txt": empty`,
+					`[GoT] Assert: <anonymous>.Output: removed file "<tmp>/output.txt": empty`,
 				},
 			},
 			{
@@ -513,7 +513,7 @@ func TestAssert(t *testing.T) {
 					Output: "hello world",
 				},
 				logs: []string{
-					`[GoT] Assert: .Output: saved file "<tmp>/output.txt" (size 11)`,
+					`[GoT] Assert: <anonymous>.Output: saved file "<tmp>/output.txt" (size 11)`,
 				},
 			},
 			{
@@ -525,7 +525,7 @@ func TestAssert(t *testing.T) {
 					Output: "hello world",
 				},
 				logs: []string{
-					`[GoT] Assert: .Output: saved file "<tmp>/output.txt" (size 11)`,
+					`[GoT] Assert: <anonymous>.Output: saved file "<tmp>/output.txt" (size 11)`,
 				},
 			},
 			{