jest/e2e/__tests__/shard.test.ts

/**
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */
import * as path from 'path';
import runJest from '../runJest';

test('--shard=1/1', () => {
  const result = runJest('shard', ['--shard=1/1', '--listTests']);

  const paths = result.stdout
    .split('\n')
    .filter(Boolean)
    .map(file => path.basename(file))
    .sort();

  expect(paths).toEqual(['1.test.js', '2.test.js', '3.test.js']);
});

test('--shard=1/2', () => {
  const result = runJest('shard', ['--shard=1/2', '--listTests']);

  const paths = result.stdout
    .split('\n')
    .filter(Boolean)
    .map(file => path.basename(file))
    .sort();

  expect(paths).toEqual(['1.test.js', '3.test.js']);
});

test('--shard=2/2', () => {
  const result = runJest('shard', ['--shard=2/2', '--listTests']);

  const paths = result.stdout
    .split('\n')
    .filter(Boolean)
    .map(file => path.basename(file));

  expect(paths).toEqual(['2.test.js']);
});

test('--shard=4/4', () => {
  const result = runJest('shard', ['--shard=4/4', '--listTests']);

  const paths = result.stdout
    .split('\n')
    .filter(Boolean)
    .map(file => path.basename(file));

  // project only has 3 files
  // shards > 3 are empty
  expect(paths).toEqual([]);
});

test('--shard=1/2 custom non-sharding test sequencer', () => {
  const result = runJest('shard', [
    '--shard=1/2',
    '--listTests',
    '--testSequencer=./no-sharding-test-sequencer.js',
  ]);

  expect(result).toMatchObject({
    failed: true,
    stderr: expect.stringMatching(
      /Shard (.*) requested, but test sequencer (.*) in (.*) has no shard method./,
    ),
  });
});

test('--shard=1/2 custom sharding test sequencer', () => {
  const result = runJest('shard', [
    '--shard=1/2',
    '--listTests',
    '--testSequencer=./sharding-test-sequencer.js',
  ]);

  const paths = result.stdout
    .split('\n')
    .filter(Boolean)
    .map(file => path.basename(file));

  expect(paths).toEqual(['3.test.js']);
});