Jest

1. others

1.1. styles

1.1.1. bad

1.1.1.1. Very bad

1.1.2. good

1.1.2.1. very good

1.1.3. not as good

1.1.4. not as bad

1.1.5. important

1.1.5.1. Very important

1.1.6. warning

1.1.7. link

1.2. AUTHOR

1.2.1. Nima Shokouhfar

1.2.1.1. Linkedin

1.2.1.1.1. Follow me on LinkedIn to stay updated on my latest professional insights and tech projects!

1.2.1.2. Youtube

1.2.1.2.1. code with nima

1.2.1.2.2. ideariver

1.2.1.3. Medium

1.2.1.3.1. ✍️ Follow me on Medium to read my latest articles on tech, coding, and innovation!

1.2.1.4. Github

1.2.1.4.1. ⭐️ Give my projects a star on GitHub and explore my repositories to discover new tools and innovations!

1.2.1.4.2. 💖 Sponsor me on GitHub to support my open-source contributions and help me create even more useful projects!

1.2.1.5. upwork

1.2.1.5.1. 💼 Hire me on Upwork for freelance projects. Let’s work together to bring your tech ideas to life!

1.2.1.6. main website: ideariver.ca

1.2.1.6.1. 🚀 Visit IdeaRiver.ca for all my latest projects, blogs, and ways to connect!

1.3. Styling Version

1.3.1. 3.0.1

2. main

2.1. Cross origin http://localhost forbidden

2.1.1. solution

2.1.1.1. test environment

2.1.1.2. link

2.2. jest does not finish gracefully

2.2.1. this will help to find out what does not closed properly

2.2.2. solution

2.2.2.1. add this to jest.config.js

2.2.2.1.1. detectOpenHandles: true, // Enable detection of open handles

2.2.3. before and after

2.2.3.1. before

2.2.3.2. after

2.3. timeout

2.4. API

2.4.1. it

2.4.1.1. Defines a test case.

2.4.1.2. It describes an individual test scenario and contains the logic you want to validate with assertions.

2.4.1.3. Example:

2.4.1.3.1. it('adds two numbers', () => { expect(1 + 2).toBe(3); });

2.4.2. describe

2.4.2.1. Groups related tests into a test suite.

2.4.2.2. Helps with organization by logically grouping related tests under the same scope.

2.4.2.3. example

2.4.2.3.1. describe('Math operations', () => { it('adds numbers', () => { expect(1 + 2).toBe(3); }); });

2.4.3. beforeAll

2.4.3.1. Runs once before all tests in the suite.

2.4.3.2. Useful for tasks that only need to happen once, like initializing data or establishing a connection.

2.4.3.3. Example:

2.4.3.3.1. beforeAll(() => { console.log('Runs before all tests'); });

2.4.4. afterAll

2.4.4.1. Runs once after all tests in the suite.

2.4.4.2. Used for final cleanup tasks such as closing connections or resetting states.

2.4.4.3. example

2.4.4.3.1. afterAll(() => { console.log('Runs after all tests'); });

2.4.5. beforeEach

2.4.5.1. Runs before every individual test within a suite.

2.4.5.2. Ideal for repetitive setup operations (e.g., creating mock objects or resetting variables).

2.4.5.3. Example:

2.4.5.3.1. beforeEach(() => { console.log('Runs before each test'); });

2.4.6. afterEach

2.4.6.1. Runs after every individual test within a suite.

2.4.6.2. Useful for cleaning up or resetting changes made during a test.

2.4.6.3. Example:

2.4.6.3.1. afterEach(() => { console.log('Runs after each test'); });

2.4.7. Example Usage of All APIs Together:

2.4.7.1. describe('User Module', () => { beforeAll(() => { console.log('Setup: Runs once before all tests'); }); afterAll(() => { console.log('Cleanup: Runs once after all tests'); }); beforeEach(() => { console.log('Runs before each test'); }); afterEach(() => { console.log('Runs after each test'); }); it('should create a user', () => { expect(true).toBe(true); // Example assertion }); it('should delete a user', () => { expect(false).toBe(false); // Example assertion }); });