fix: if oneOf contains multiple strings and the data doesn't match the last regex, the String attribute will be overwritten to nil

Author: marceljk

templates/go/custom/model_oneof_test.mustache

@@ -44,6 +44,13 @@ func Test{{{classname}}}_UnmarshalJSON(t *testing.T) {
 			if err := v.UnmarshalJSON(tt.args.src); (err != nil) != tt.wantErr {
 				t.Errorf("UnmarshalJSON() error = %v, wantErr %v", err, tt.wantErr)
 			}
+            marshalJson, err := v.MarshalJSON()
+            if err != nil {
+                t.Fatalf("failed marshalling {{classname}}: %v", err)
+            }
+            if string(marshalJson) != string(tt.args.src) {
+                t.Fatalf("wanted %s, get %s", tt.args.src, marshalJson)
+            }
 		})
 	}
 }

templates/go/model_oneof.mustache

@@ -59,23 +59,21 @@ func (dst *{{classname}}) UnmarshalJSON(data []byte) error {
 	{{#composedSchemas.oneOf}}
         {{#dataType}}
 	// try to unmarshal data into {{#lambda.type-to-name}}{{{.}}}{{/lambda.type-to-name}}
-	err = json.Unmarshal(data, &dst.{{#lambda.type-to-name}}{{{.}}}{{/lambda.type-to-name}})
+	dst{{classname}}{{-index}} := &{{classname}}{}
+	err = json.Unmarshal(data, &dst{{classname}}{{-index}}.{{#lambda.type-to-name}}{{{.}}}{{/lambda.type-to-name}})
 	if err == nil {
-		json{{{.}}}, _ := json.Marshal(dst.{{#lambda.type-to-name}}{{{.}}}{{/lambda.type-to-name}})
+		json{{{.}}}, _ := json.Marshal(&dst{{classname}}{{-index}}.{{#lambda.type-to-name}}{{{.}}}{{/lambda.type-to-name}})
         {{#pattern}}
         regex := `{{.}}`
         regex = regexp.MustCompile("^\\/|\\/$").ReplaceAllString(regex, "$1") // Remove beginning slash and ending slash
         regex = regexp.MustCompile("\\\\(.)").ReplaceAllString(regex, "$1") // Remove duplicate escaping char for dots
-        rawString := regexp.MustCompile(`^"|"$`).ReplaceAllString(*dst.String, "$1") // Remove quotes
+        rawString := regexp.MustCompile(`^"|"$`).ReplaceAllString(*dst{{classname}}{{-index}}.{{#lambda.type-to-name}}{{dataType}}{{/lambda.type-to-name}}, "$1") // Remove quotes
         isMatched, _ := regexp.MatchString(regex, rawString)
         {{/pattern}}
-		if string(json{{{.}}}) == "{}" {{#pattern}}|| !isMatched {{/pattern}} { // empty struct
-			dst.{{#lambda.type-to-name}}{{{.}}}{{/lambda.type-to-name}} = nil
-        } else {
+		if string(json{{{.}}}) != "{}" {{#pattern}}&& isMatched {{/pattern}} { // empty struct
+			dst.{{#lambda.type-to-name}}{{{.}}}{{/lambda.type-to-name}} = dst{{classname}}{{-index}}.{{#lambda.type-to-name}}{{{.}}}{{/lambda.type-to-name}}
 			match++
 		}
-	} else {
-		dst.{{#lambda.type-to-name}}{{{.}}}{{/lambda.type-to-name}} = nil
 	}
 
         {{/dataType}}