CodePamoja
CodePamoja means "Code Together" in Swahili. We are a group of passionate developers in The Netherlands and Kenya working together in virtual teams, transferring the latest software development skills to each other.
Jest.js
Why use Jest?
Why use Jest?
- It's fast
- Easy to configure
- Snapshot testing
- Build for testing JavaScript (Optimized for ReactJS)
- Used by Facebook (maintainer),
Twitter, Spotify, AirBnB,
New York Times, Instagram
Jest built-in features
Jest built-in features
- Mocking
- Snapshotting
- Typescript support
- Coverage report
Jest methods
describe()
With describe, you define a test suite that can contain 1 or more tests.
test() or it()
With test or it method, you define a test.
expect()
With the expect method is a matcher which returns the output to the next method. For example toBe()
Check other matcher methods: https://jestjs.io/docs/en/expect
Jest mocking
What is mocking?
The goal for mocking is to replace something we don’t control with something we do, so it’s important that what we replace it with has all the features we need.
When to use mocking?
The goal for mocking is to replace something we don’t control with something we do, so it’s important that what we replace it with has all the features we need.
Jest.js
By CodePamoja
