Function matchDomElement

packages/core/test/render3/matchers.ts:150–196

(
  expectedTagName: string | undefined = undefined,
  expectedAttrs: {[key: string]: string | null} = {},
)

 * @param expectedAttributes optional DOM element properties.
 */
export function matchDomElement(
  expectedTagName: string | undefined = undefined,
  expectedAttrs: {[key: string]: string | null} = {},
): jasmine.AsymmetricMatcher<Element> {
  const matcher = function () {};
  let _actual: any = null;

  matcher.asymmetricMatch = function (actual: any) {
    _actual = actual;
    if (!isDOMElement(actual)) return false;
    if (expectedTagName && expectedTagName.toUpperCase() !== actual.tagName.toUpperCase()) {
      return false;
    }
    if (expectedAttrs) {
      for (const attrName in expectedAttrs) {
        if (expectedAttrs.hasOwnProperty(attrName)) {
          const expectedAttrValue = expectedAttrs[attrName];
          const actualAttrValue = actual.getAttribute(attrName);
          if (expectedAttrValue !== actualAttrValue) {
            return false;
          }
        }
      }
    }
    return true;
  };
  matcher.jasmineToString = function () {
    let actualStr = isDOMElement(_actual)
      ? `<${_actual.tagName}${toString(_actual.attributes)}>`
      : JSON.stringify(_actual);
    let expectedStr = `<${expectedTagName || '*'}${Object.entries(expectedAttrs).map(
      ([key, value]) => ` ${key}=${JSON.stringify(value)}`,
    )}>`;
    return `[${actualStr} != ${expectedStr}]`;
  };

  function toString(attrs: NamedNodeMap) {
    let text = '';
    for (let i = 0; i < attrs.length; i++) {
      const attr = attrs[i];
      text += ` ${attr.name}=${JSON.stringify(attr.value)}`;
    }
    return text;
  }

  return matcher;
}

/**
 * Asymmetric matcher which matches DOM text node.