utils.test.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.
 */

jest.mock('graceful-fs', () => ({
  ...jest.createMockFromModule<typeof import('fs')>('fs'),
  existsSync: jest.fn().mockReturnValue(true),
}));

import * as path from 'path';
import assert = require('assert');
import * as fs from 'graceful-fs';
import chalk = require('chalk');

import {
  SNAPSHOT_GUIDE_LINK,
  SNAPSHOT_VERSION,
  SNAPSHOT_VERSION_WARNING,
  addExtraLineBreaks,
  deepMerge,
  getSnapshotData,
  keyToTestName,
  removeExtraLineBreaks,
  removeLinesBeforeExternalMatcherTrap,
  saveSnapshotFile,
  serialize,
  testNameToKey,
} from '../utils';

test('keyToTestName()', () => {
  expect(keyToTestName('abc cde 12')).toBe('abc cde');
  expect(keyToTestName('abc cde   12')).toBe('abc cde  ');
  expect(() => keyToTestName('abc cde')).toThrowError(
    'Snapshot keys must end with a number.',
  );
});

test('testNameToKey', () => {
  expect(testNameToKey('abc cde', 1)).toBe('abc cde 1');
  expect(testNameToKey('abc cde ', 12)).toBe('abc cde  12');
});

test('saveSnapshotFile() works with \r\n', () => {
  const filename = path.join(__dirname, 'remove-newlines.snap');
  const data = {
    myKey: '<div>\r\n</div>',
  };

  saveSnapshotFile(data, filename);
  expect(fs.writeFileSync).toBeCalledWith(
    filename,
    `// Jest Snapshot v1, ${SNAPSHOT_GUIDE_LINK}\n\n` +
      'exports[`myKey`] = `<div>\n</div>`;\n',
  );
});

test('saveSnapshotFile() works with \r', () => {
  const filename = path.join(__dirname, 'remove-newlines.snap');
  const data = {
    myKey: '<div>\r</div>',
  };

  saveSnapshotFile(data, filename);
  expect(fs.writeFileSync).toBeCalledWith(
    filename,
    `// Jest Snapshot v1, ${SNAPSHOT_GUIDE_LINK}\n\n` +
      'exports[`myKey`] = `<div>\n</div>`;\n',
  );
});

test('getSnapshotData() throws when no snapshot version', () => {
  const filename = path.join(__dirname, 'old-snapshot.snap');
  (fs.readFileSync as jest.Mock).mockImplementation(
    () => 'exports[`myKey`] = `<div>\n</div>`;\n',
  );
  const update = 'none';

  expect(() => getSnapshotData(filename, update)).toThrowError(
    chalk.red(
      `${chalk.bold('Outdated snapshot')}: No snapshot header found. ` +
        `Jest 19 introduced versioned snapshots to ensure all developers on ` +
        `a project are using the same version of Jest. ` +
        `Please update all snapshots during this upgrade of Jest.\n\n`,
    ) + SNAPSHOT_VERSION_WARNING,
  );
});

test('getSnapshotData() throws for older snapshot version', () => {
  const filename = path.join(__dirname, 'old-snapshot.snap');
  (fs.readFileSync as jest.Mock).mockImplementation(
    () =>
      `// Jest Snapshot v0.99, ${SNAPSHOT_GUIDE_LINK}\n\n` +
      'exports[`myKey`] = `<div>\n</div>`;\n',
  );
  const update = 'none';

  expect(() => getSnapshotData(filename, update)).toThrowError(
    chalk.red(
      `${chalk.red.bold('Outdated snapshot')}: The version of the snapshot ` +
        `file associated with this test is outdated. The snapshot file ` +
        `version ensures that all developers on a project are using ` +
        `the same version of Jest. ` +
        `Please update all snapshots during this upgrade of Jest.\n\n`,
    ) +
      `Expected: v${SNAPSHOT_VERSION}\n` +
      `Received: v0.99\n\n` +
      SNAPSHOT_VERSION_WARNING,
  );
});

test('getSnapshotData() throws for newer snapshot version', () => {
  const filename = path.join(__dirname, 'old-snapshot.snap');
  (fs.readFileSync as jest.Mock).mockImplementation(
    () =>
      `// Jest Snapshot v2, ${SNAPSHOT_GUIDE_LINK}\n\n` +
      'exports[`myKey`] = `<div>\n</div>`;\n',
  );
  const update = 'none';

  expect(() => getSnapshotData(filename, update)).toThrowError(
    chalk.red(
      `${chalk.red.bold('Outdated Jest version')}: The version of this ` +
        `snapshot file indicates that this project is meant to be used ` +
        `with a newer version of Jest. ` +
        `The snapshot file version ensures that all developers on a project ` +
        `are using the same version of Jest. ` +
        `Please update your version of Jest and re-run the tests.\n\n`,
    ) +
      `Expected: v${SNAPSHOT_VERSION}\n` +
      `Received: v2`,
  );
});

test('getSnapshotData() does not throw for when updating', () => {
  const filename = path.join(__dirname, 'old-snapshot.snap');
  (fs.readFileSync as jest.Mock).mockImplementation(
    () => 'exports[`myKey`] = `<div>\n</div>`;\n',
  );
  const update = 'all';

  expect(() => getSnapshotData(filename, update)).not.toThrow();
});

test('getSnapshotData() marks invalid snapshot dirty when updating', () => {
  const filename = path.join(__dirname, 'old-snapshot.snap');
  (fs.readFileSync as jest.Mock).mockImplementation(
    () => 'exports[`myKey`] = `<div>\n</div>`;\n',
  );
  const update = 'all';

  expect(getSnapshotData(filename, update)).toMatchObject({dirty: true});
});

test('getSnapshotData() marks valid snapshot not dirty when updating', () => {
  const filename = path.join(__dirname, 'old-snapshot.snap');
  (fs.readFileSync as jest.Mock).mockImplementation(
    () =>
      `// Jest Snapshot v${SNAPSHOT_VERSION}, ${SNAPSHOT_GUIDE_LINK}\n\n` +
      'exports[`myKey`] = `<div>\n</div>`;\n',
  );
  const update = 'all';

  expect(getSnapshotData(filename, update)).toMatchObject({dirty: false});
});

test('escaping', () => {
  const filename = path.join(__dirname, 'escaping.snap');
  const data = '"\'\\';
  const writeFileSync = fs.writeFileSync as jest.Mock;

  writeFileSync.mockReset();
  saveSnapshotFile({key: data}, filename);
  const writtenData = writeFileSync.mock.calls[0][1];
  expect(writtenData).toBe(
    `// Jest Snapshot v1, ${SNAPSHOT_GUIDE_LINK}\n\n` +
      'exports[`key`] = `"\'\\\\`;\n',
  );

  // @ts-expect-error
  const exports = {}; // eslint-disable-line @typescript-eslint/no-unused-vars
  // eslint-disable-next-line no-eval
  const readData = eval('var exports = {}; ' + writtenData + ' exports');
  expect(readData).toEqual({key: data});
  const snapshotData = readData.key;
  expect(data).toEqual(snapshotData);
});

test('serialize handles \\r\\n', () => {
  const data = '<div>\r\n</div>';
  const serializedData = serialize(data);

  expect(serializedData).toBe('"<div>\n</div>"');
});

describe('ExtraLineBreaks', () => {
  test('0 empty string', () => {
    const expected = '';

    const added = addExtraLineBreaks(expected);
    const removed = removeExtraLineBreaks(added);

    expect(added).toBe(expected);
    expect(removed).toBe(expected);
  });

  test('1 line has double quote marks at edges', () => {
    const expected = '" one line "';

    const added = addExtraLineBreaks(expected);
    const removed = removeExtraLineBreaks(added);

    expect(added).toBe(expected);
    expect(removed).toBe(expected);
  });

  test('1 line has spaces at edges', () => {
    const expected = ' one line ';

    const added = addExtraLineBreaks(expected);
    const removed = removeExtraLineBreaks(added);

    expect(added).toBe(expected);
    expect(removed).toBe(expected);
  });

  test('2 lines both are blank', () => {
    const expected = '\n';

    const added = addExtraLineBreaks(expected);
    const removed = removeExtraLineBreaks(added);

    expect(added).toBe('\n' + expected + '\n');
    expect(removed).toBe(expected);
  });

  test('2 lines have double quote marks at edges', () => {
    const expected = '"\n"';

    const added = addExtraLineBreaks(expected);
    const removed = removeExtraLineBreaks(added);

    expect(added).toBe('\n' + expected + '\n');
    expect(removed).toBe(expected);
  });

  test('2 lines first is blank', () => {
    const expected = '\nsecond line ';

    const added = addExtraLineBreaks(expected);
    const removed = removeExtraLineBreaks(added);

    expect(added).toBe('\n' + expected + '\n');
    expect(removed).toBe(expected);
  });

  test('2 lines last is blank', () => {
    const expected = ' first line\n';

    const added = addExtraLineBreaks(expected);
    const removed = removeExtraLineBreaks(added);

    expect(added).toBe('\n' + expected + '\n');
    expect(removed).toBe(expected);
  });
});

describe('removeLinesBeforeExternalMatcherTrap', () => {
  test('contains external matcher trap', () => {
    const stack = `Error:
    at SnapshotState._addSnapshot (/jest/packages/jest-snapshot/build/State.js:150:9)
    at SnapshotState.match (/jest/packages/jest-snapshot/build/State.js:303:14)
    at _toMatchSnapshot (/jest/packages/jest-snapshot/build/index.js:399:32)
    at _toThrowErrorMatchingSnapshot (/jest/packages/jest-snapshot/build/index.js:585:10)
    at Object.toThrowErrorMatchingInlineSnapshot (/jest/packages/jest-snapshot/build/index.js:504:10)
    at Object.<anonymous> (/jest/packages/expect/build/index.js:138:20)
    at __EXTERNAL_MATCHER_TRAP__ (/jest/packages/expect/build/index.js:378:30)
    at throwingMatcher (/jest/packages/expect/build/index.js:379:15)
    at /jest/packages/expect/build/index.js:285:72
    at Object.<anonymous> (/jest/e2e/to-throw-error-matching-inline-snapshot/__tests__/should-support-rejecting-promises.test.js:3:7)`;

    const expected = `    at throwingMatcher (/jest/packages/expect/build/index.js:379:15)
    at /jest/packages/expect/build/index.js:285:72
    at Object.<anonymous> (/jest/e2e/to-throw-error-matching-inline-snapshot/__tests__/should-support-rejecting-promises.test.js:3:7)`;

    expect(removeLinesBeforeExternalMatcherTrap(stack)).toBe(expected);
  });

  test("doesn't contain external matcher trap", () => {
    const stack = `Error:
    at SnapshotState._addSnapshot (/jest/packages/jest-snapshot/build/State.js:150:9)
    at SnapshotState.match (/jest/packages/jest-snapshot/build/State.js:303:14)
    at _toMatchSnapshot (/jest/packages/jest-snapshot/build/index.js:399:32)
    at _toThrowErrorMatchingSnapshot (/jest/packages/jest-snapshot/build/index.js:585:10)
    at Object.toThrowErrorMatchingInlineSnapshot (/jest/packages/jest-snapshot/build/index.js:504:10)
    at Object.<anonymous> (/jest/packages/expect/build/index.js:138:20)
    at throwingMatcher (/jest/packages/expect/build/index.js:379:15)
    at /jest/packages/expect/build/index.js:285:72
    at Object.<anonymous> (/jest/e2e/to-throw-error-matching-inline-snapshot/__tests__/should-support-rejecting-promises.test.js:3:7)`;

    expect(removeLinesBeforeExternalMatcherTrap(stack)).toBe(stack);
  });
});

describe('DeepMerge with property matchers', () => {
  const matcher = expect.any(String);

  /* eslint-disable sort-keys */
  // to keep keys in numerical order rather than alphabetical
  const cases = [
    [
      'a nested object',
      // Target
      {
        data: {
          one: 'one',
          two: 'two',
        },
      },
      // Matchers
      {
        data: {
          two: matcher,
        },
      },
      // Expected
      {
        data: {
          one: 'one',
          two: matcher,
        },
      },
    ],

    [
      'an object with an array of objects',
      // Target
      {
        data: {
          one: [
            {
              two: 'two',
              three: 'three',
            },
            // Include an array element not present in the propertyMatchers
            {
              four: 'four',
              five: 'five',
            },
          ],
          six: [{seven: 'seven'}],
          nine: [[{ten: 'ten'}]],
        },
      },
      // Matchers
      {
        data: {
          one: [
            {
              two: matcher,
            },
          ],
          six: [
            {seven: matcher},
            // Include an array element not present in the target
            {eight: matcher},
          ],
          nine: [[{ten: matcher}]],
        },
      },
      // Expected
      {
        data: {
          one: [
            {
              two: matcher,
              three: 'three',
            },
            {
              four: 'four',
              five: 'five',
            },
          ],
          six: [{seven: matcher}, {eight: matcher}],
          nine: [[{ten: matcher}]],
        },
      },
    ],

    [
      'an object with an array of strings',
      // Target
      {
        data: {
          one: ['one'],
          two: ['two'],
          three: ['three', 'four'],
          five: ['five'],
        },
      },
      // Matchers
      {
        data: {
          one: [matcher],
          two: ['two'],
          three: [matcher],
          five: 'five',
        },
      },
      // Expected
      {
        data: {
          one: [matcher],
          two: ['two'],
          three: [matcher, 'four'],
          five: 'five',
        },
      },
    ],

    [
      'an array of objects',
      // Target
      [{name: 'one'}, {name: 'two'}, {name: 'three'}],
      // Matchers
      [{name: 'one'}, {name: matcher}, {name: matcher}],
      // Expected
      [{name: 'one'}, {name: matcher}, {name: matcher}],
    ],

    [
      'an array of arrays',
      // Target
      [['one'], ['two'], ['three']],
      // Matchers
      [['one'], [matcher], [matcher]],
      // Expected
      [['one'], [matcher], [matcher]],
    ],
  ];
  /* eslint-enable sort-keys */

  it.each(cases)(
    'Correctly merges %s',
    (_case, target, propertyMatchers, expected) => {
      const originalTarget = JSON.parse(JSON.stringify(target));
      const mergedOutput = deepMerge(target, propertyMatchers);

      // Use assert.deepStrictEqual() instead of expect().toStrictEqual()
      // since we want to actually validate that we got the matcher
      // rather than treat it specially the way that expect() does
      assert.deepStrictEqual(mergedOutput, expected);

      // Ensure original target is not modified
      expect(target).toStrictEqual(originalTarget);
    },
  );
});