extractExpectedAssertionsErrors.ts

/**
 * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 */

import {
  EXPECTED_COLOR,
  RECEIVED_COLOR,
  matcherHint,
  pluralize,
} from 'jest-matcher-utils';

import {getState, setState} from './jestMatchersObject';

const resetAssertionsLocalState = () => {
  setState({
    assertionCalls: 0,
    expectedAssertionsNumber: null,
    isExpectingAssertions: false,
  });
};

type AssertionsErrors = Array<{
  actual: string;
  error: string;
  expected: string | number;
}>;

// Create and format all errors related to the mismatched number of `expect`
// calls and reset the matcher's state.
const extractExpectedAssertionsErrors: () => AssertionsErrors = () => {
  const result: AssertionsErrors = [];
  const {
    assertionCalls,
    expectedAssertionsNumber,
    expectedAssertionsNumberError,
    isExpectingAssertions,
    isExpectingAssertionsError,
  } = getState();

  resetAssertionsLocalState();

  if (
    typeof expectedAssertionsNumber === 'number' &&
    assertionCalls !== expectedAssertionsNumber
  ) {
    const numOfAssertionsExpected = EXPECTED_COLOR(
      pluralize('assertion', expectedAssertionsNumber),
    );

    expectedAssertionsNumberError.message =
      matcherHint('.assertions', '', String(expectedAssertionsNumber), {
        isDirectExpectCall: true,
      }) +
      '\n\n' +
      `Expected ${numOfAssertionsExpected} to be called but received ` +
      RECEIVED_COLOR(pluralize('assertion call', assertionCalls || 0)) +
      '.';

    result.push({
      actual: assertionCalls,
      error: expectedAssertionsNumberError,
      expected: expectedAssertionsNumber,
    });
  }
  if (isExpectingAssertions && assertionCalls === 0) {
    const expected = EXPECTED_COLOR('at least one assertion');
    const received = RECEIVED_COLOR('received none');

    isExpectingAssertionsError.message =
      matcherHint('.hasAssertions', '', '', {
        isDirectExpectCall: true,
      }) +
      '\n\n' +
      `Expected ${expected} to be called but ${received}.`;

    result.push({
      actual: 'none',
      error: isExpectingAssertionsError,
      expected: 'at least one',
    });
  }

  return result;
};

export default extractExpectedAssertionsErrors;