Function makeResolveMatcher

packages/expect/src/index.ts:164–217

(
    matcherName: string,
    matcher: RawMatcherFn,
    isNot: boolean,
    actual: Promise<any> | (() => Promise<any>),
    outerErr: JestAssertionError,
  )

const makeResolveMatcher =
  (
    matcherName: string,
    matcher: RawMatcherFn,
    isNot: boolean,
    actual: Promise<any> | (() => Promise<any>),
    outerErr: JestAssertionError,
  ): PromiseMatcherFn =>
  (...args) => {
    const options = {
      isNot,
      promise: 'resolves',
    };

    const actualWrapper: Promise<any> =
      typeof actual === 'function' ? actual() : actual;

    if (!isPromise(actualWrapper)) {
      throw new JestAssertionError(
        matcherUtils.matcherErrorMessage(
          matcherUtils.matcherHint(matcherName, undefined, '', options),
          `${matcherUtils.RECEIVED_COLOR(
            'received',
          )} value must be a promise or a function returning a promise`,
          matcherUtils.printWithType(
            'Received',
            actual,
            matcherUtils.printReceived,
          ),
        ),
      );
    }

    const innerErr = new JestAssertionError();

    return actualWrapper.then(
      result =>
        makeThrowingMatcher(matcher, isNot, 'resolves', result, innerErr).apply(
          null,
          args,
        ),
      error => {
        outerErr.message =
          `${matcherUtils.matcherHint(
            matcherName,
            undefined,
            '',
            options,
          )}\n\n` +
          'Received promise rejected instead of resolved\n' +
          `Rejected to value: ${matcherUtils.printReceived(error)}`;
        throw outerErr;
      },
    );
  };

const makeRejectMatcher =
  (