JavaScript testing

Archived

This page has been archived and will receive no further updates.

Current preferred testing framework as of 2017: Jest

Jest

Set up Jest

Install Jest

yarn add --dev jest

Or:

npm install --save-dev jest

Update package.json
```
  "scripts": {
    "test": "jest"
```
If you wish to report coverage
1. Update package.json
```
  "scripts": {
    "test": "jest --coverage"
```
2. Install coverage library
```
yarn add --dev coveralls
```
  Or:
```
npm install --save-dev coveralls
```
3. Make sure linter ignores coverage folder
  - Point eslint to specific folder
    "scripts": { "lint": "eslint src/*",
  - Or, add coverage to .eslintignore
Configure linter for Jest
1. Add this to your .eslintrc or .eslintrc.js:
```
  "env": {
    "jest": true,
```
Run jest to make sure it’s working
```
yarn test
```
Or:
```
npm test
```
Create your first test
1. In the same folder as the Javascript file you want to test, create a __tests__ folder
2. Create a tests file with the same name as the Javascript file you’re testing, but with a .test.js extension
3. Write your test
  
  https://facebook.github.io/jest/docs/en/getting-started.html