fix @x-tagGroups (#1010)

* test x-tagGroup

* fix x-tagGroups issue

parser.go

@@ -318,13 +318,13 @@ func parseGeneralAPIInfo(parser *Parser, comments []string) error {
 
 	// parsing classic meta data model
 	for i, commentLine := range comments {
-		attribute := strings.ToLower(strings.Split(commentLine, " ")[0])
+		attribute := strings.Split(commentLine, " ")[0]
 		value := strings.TrimSpace(commentLine[len(attribute):])
 		multilineBlock := false
 		if previousAttribute == attribute {
 			multilineBlock = true
 		}
-		switch attribute {
+		switch strings.ToLower(attribute) {
 		case "@version":
 			parser.swagger.Info.Version = value
 		case "@title":
@@ -460,7 +460,10 @@ func parseGeneralAPIInfo(parser *Parser, comments []string) error {
 				if strings.Contains(extensionName, "logo") {
 					parser.swagger.Info.Extensions.Add(extensionName, valueJSON)
 				} else {
-					parser.swagger.AddExtension(extensionName, valueJSON)
+					if parser.swagger.Extensions == nil {
+						parser.swagger.Extensions = make(map[string]interface{})
+					}
+					parser.swagger.Extensions[attribute[1:]] = valueJSON
 				}
 			}
 		}

parser_test.go

@@ -398,6 +398,19 @@ func TestParser_ParseGeneralAPIInfoCollectionFromat(t *testing.T) {
 	assert.Equal(t, parser.collectionFormatInQuery, "tsv")
 }
 
+func TestParser_ParseGeneralAPITagGroups(t *testing.T) {
+	t.Parallel()
+
+	parser := New()
+	assert.NoError(t, parseGeneralAPIInfo(parser, []string{
+		"@x-tagGroups [{\"name\":\"General\",\"tags\":[\"lanes\",\"video-recommendations\"]}]",
+	}))
+
+	expected := []interface{}{map[string]interface{}{"name": "General", "tags": []interface{}{"lanes", "video-recommendations"}}}
+	assert.Equal(t, parser.swagger.Extensions["x-tagGroups"], expected)
+
+}
+
 func TestParser_ParseGeneralAPITagDocs(t *testing.T) {
 	t.Parallel()