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Execution order of Jest/Jasmine test code
Raw
README.md

Demonstrate execution order of code in Jest/Jasmine

How to run it:

  • Install Jest npm i -g jest
  • Save runOrder.test.js in a folder (ensure it is named with .test.js as a suffix)
  • Run jest in that folder

Key points

  • Any code not inside of it, beforeAll, afterAll, beforeEach or afterEach runs immediately on initialisation.
    • This means code at the end of your file runs before even your before hooks.
    • Code inside a describe block runs even if the block or file has no active tests.
  • *All hooks wrap *Each hooks, i.e.
    • For a given test all beforeAll hooks will have run before the first beforeEach hook runs, regardless of the order in which they are defined and nested.
    • Similarly afterAll hooks run after all afterEach hooks.
Raw
runOrder.test.js
/**
* Demonstrate execution order of code in Jest/Jasmine
*/
console.log('Before describes');
describe('First test', () => {
console.log('Inside first test describe');
beforeAll(() => console.log('Before all'));
afterAll(() => console.log('After all'));
beforeEach(() => console.log('Before each'));
afterEach(() => console.log('After each'));
describe('Inner', () => {
beforeAll(() => console.log('Before all inner'));
afterAll(() => console.log('After all inner'));
beforeEach(() => console.log('Before each inner'));
afterEach(() => console.log('After each inner'));
it('runs a test', () => console.log('>>> Running first test'));
it('runs another test', () => console.log('>>> Running second test'));
});
it('runs this test too', () => console.log('>>> Running third test'));
});
console.log('Between describes');
describe('Second test', () => {
console.log('Inside second test describe');
it.skip('doesn\'t run this test', () => console.log('Nope'));
});
console.log('After describes');
Raw
terminal-log.txt
$ jest
PASS ./runOrder.test.js
First test
✓ runs this test too
Inner
✓ runs a test (1ms)
✓ runs another test
Second test
○ doesn't run this test
Test Suites: 1 passed, 1 total
Tests: 1 skipped, 3 passed, 4 total
Snapshots: 0 total
Time: 0.619s, estimated 1s
Ran all test suites.
console.log runOrder.test.js:10
Before describes
console.log runOrder.test.js:14
Inside first test describe
console.log runOrder.test.js:34
Between describes
console.log runOrder.test.js:38
Inside second test describe
console.log runOrder.test.js:44
After describes
console.log runOrder.test.js:16
Before all
console.log runOrder.test.js:22
Before all inner
console.log runOrder.test.js:18
Before each
console.log runOrder.test.js:24
Before each inner
console.log runOrder.test.js:27
>>> Running first test
console.log runOrder.test.js:25
After each inner
console.log runOrder.test.js:19
After each
console.log runOrder.test.js:18
Before each
console.log runOrder.test.js:24
Before each inner
console.log runOrder.test.js:28
>>> Running second test
console.log runOrder.test.js:25
After each inner
console.log runOrder.test.js:19
After each
console.log runOrder.test.js:23
After all inner
console.log runOrder.test.js:18
Before each
console.log runOrder.test.js:31
>>> Running third test
console.log runOrder.test.js:19
After each
console.log runOrder.test.js:17
After all
@chuckplantain
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chuckplantain commented Apr 5, 2018 •
edited
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async version of above, fwiw: https://gist.github.com/chuckplantain/8359063a1c025b5ccfce52b4f5707368

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