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Patch `beforeAll` and `afterAll` hooks to work with `jest.retryTimes`

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wix-incubator/jest-retry-all-hooks

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jest-retry-all-hooks

Patch beforeAll and afterAll hooks to work with jest.retryTimes.

Motivation

jest.retryTimes(1);

beforeAll(() => {
  // This is a part of a root or a nested describe block, and it is not retried normally.
});

test('test', () => {
  // The tests and their `beforeEach` and `afterEach` hooks are retried.
});

afterAll(() => {
  // This is a part of a root or a nested describe block, and it is not retried normally.
});

So, what does this library do? It converts beforeAll and afterAll hooks to smart beforeEach and afterEach hooks, which usually run only once, but if a test fails with an error, here is what happens:

jest.retryTimes(1);

beforeEach(() => {
  // if never ran before, run a function passed to `beforeAll`
  // if previous test failed, run that function again
});

test('test', () => {
  // The behavior `test`, `beforeEach`, `afterEach` stays the same.
});

afterEach(() => {
  // if the test function or preceeding hooks failed, run a function passed to `afterAll`
});

afterAll(() => {
  // if never ran before, run a function passed to `afterAll`
});

See the tests/hooks.ts for an elaborate example of how it works:

B b -1 a A
B b -2 a A
B b  3 a
  b  1 a
  b -2 a A
B b  2 a A

The example above demonstrates how jest.retryTimes(2) will work with the patched beforeAll (B), beforeEach (b), afterEach (a), and afterAll (A) hooks and flaky tests (1, 2, 3), where negative numbers indicate failures, and positive numbers indicate successes.

Please note that the patched beforeAll and afterAll hooks won't be associated with describe blocks, so they will be executed whenever a test fails, even if the afterAll hook seems to be outside the describe block.

Installation

Install the package:

npm install --save-dev jest-retry-all-hooks

Add to your jest.config.js:

- testEnvironment: 'node',
+ testEnvironment: 'jest-environment-emit/node',
+ testEnvironmentOptions: {
+   eventListeners: [
+     'jest-retry-all-hooks',
+   ],
+ },

If you don't have jest-enviroment-emit installed, you can install it:

npm install --save-dev jest-environment-emit

You can also use any other test environment compatible with jest-environment-emit, e.g.:

Use GitHub Topic Search to find more compatible test environments.

License

Licensed under the MIT License.