Function defaultHttpResponseTransform

test/angular/1.7/angular.js:12010–12034

(data, headers)

}

function defaultHttpResponseTransform(data, headers) {
  if (isString(data)) {
    // Strip json vulnerability protection prefix and trim whitespace
    var tempData = data.replace(JSON_PROTECTION_PREFIX, '').trim();

    if (tempData) {
      var contentType = headers('Content-Type');
      var hasJsonContentType = contentType && (contentType.indexOf(APPLICATION_JSON) === 0);

      if (hasJsonContentType || isJsonLike(tempData)) {
        try {
          data = fromJson(tempData);
        } catch (e) {
          if (!hasJsonContentType) {
            return data;
          }
          throw $httpMinErr('baddata', 'Data must be a valid JSON object. Received: "{0}". ' +
          'Parse error: "{1}"', data, e);
        }
      }
    }
  }

  return data;
}

function isJsonLike(str) {
    var jsonStart = str.match(JSON_START);