jest --bail

[leontastic]

Is this a bug report?

No

Feature Request: Support jest --bail

I would like to override the CRA test script with --bail. I can't imagine this would break anything in CRA, but I don't want to npm run eject just because I can't bail on the first test.

[bugzpodder]

you can pass your own command line arguments to yarn test and it will get forwarded. So:
yarn test --watchAll=false --bail
npm test -- --watchAll=false --bail

[leontastic]

@bugzpodder I tried your advice, it seems subsequent tests are still run after a test or hook fails. That's not what I expect from --bail. From jest docs:

Alias: -b. Exit the test suite immediately upon n number of failing test suite. Defaults to 1.

Maybe I'm misinterpreting the expected behavior here? Isn't supposed to --bail cause subsequent tests to be skipped when one test fails? Exit the test suite immediately?

[bugzpodder]

I just ran:
yarn test --watchAll=false --bail and it worked for me. The test runner stopped after the first one failed. I removed the number 2 from my previous command.

[leontastic]

@bugzpodder Here is a minimal repro I prepared: https://github.com/leontastic/react-scripts-test-script-doesnt-accept-jest-bail-config

The repro was created by calling npx create-react-app to create a new project and adding two failing tests.

Here is my output running yarn test --watchAll=false --bail:

leonli@Leons-MBP:react-scripts-test-script-doesnt-accept-jest-bail-config (master)$ yarn test --watchAll=false --bail
yarn run v1.12.3
$ react-scripts test --watchAll=false --bail
 FAIL  src/App.test.js
  ✓ renders without crashing (22ms)
  ✕ should fail (4ms)
  ✕ should not run this test

  ● should fail

    fail

      10 |
      11 | it('should fail', () => {
    > 12 |   throw new Error('fail')
         |         ^
      13 | });
      14 |
      15 | it('should not run this test', () => {

      at Object.<anonymous>.it (src/App.test.js:12:9)

  ● should not run this test

    fail

      14 |
      15 | it('should not run this test', () => {
    > 16 |   throw new Error('fail')
         |         ^
      17 | });
      18 |

      at Object.<anonymous>.it (src/App.test.js:16:9)

Test Suites: 1 failed, 1 total
Tests:       2 failed, 1 passed, 3 total
Snapshots:   0 total
Time:        1.017s
Ran all test suites.
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

Clearly the subsequent failing test is being run here, where I would expect --bail to skip the rest of the tests.

[bugzpodder]

Note that jest runs a small number of tests in parallel by default, you'll have to disable it using another flag: https://jestjs.io/docs/en/cli#maxconcurrency-num

[leontastic]

I did more digging and it looks like this behavior is by design 😱jestjs/jest#7434

I guess this makes this issue out of CRA's control, I'll close this issue and hope someone fixes this in Jest soon or PR Jest myself if there's no progress 😕

Thank you for your time and patience looking into this @bugzpodder 😄