Function functionContaining

packages/core/test/render3/jit/matcher.ts:12–59

(
  expectedFragments: Array<string | RegExp>,
)

 * Jasmine matcher to verify that a function contains the provided code fragments.
 */
export function functionContaining(
  expectedFragments: Array<string | RegExp>,
): jasmine.AsymmetricMatcher<Function> {
  let _actual: Function | null = null;

  const matches = (code: string, fragment: string | RegExp): boolean => {
    if (typeof fragment === 'string') {
      return code.includes(fragment);
    } else {
      return fragment.test(code);
    }
  };

  return {
    asymmetricMatch(actual: Function): boolean {
      _actual = actual;

      if (typeof actual !== 'function') {
        return false;
      }
      const code = actual.toString();
      for (const fragment of expectedFragments) {
        if (!matches(code, fragment)) {
          return false;
        }
      }
      return true;
    },
    jasmineToString(pp: (value: any) => string): string {
      if (typeof _actual !== 'function') {
        return `Expected function to contain code fragments ${pp(expectedFragments)} but got ${pp(
          _actual,
        )}`;
      }
      const errors: string[] = [];
      const code = _actual.toString();
      errors.push(
        `The actual function with code:\n${code}\n\ndid not contain the following fragments:`,
      );
      for (const fragment of expectedFragments) {
        if (!matches(code, fragment)) {
          errors.push(`- ${fragment}`);
        }
      }
      return errors.join('\n');
    },
  };
}