Rollup preprocessor for Jest
npm install rollup-jestRollup preprocessor for Jest.
``bash`
npm install rollup-jest rollup --save-dev
Add preset to Jest config:
`json
{
"jest": {
"preset": "rollup-jest"
}
}
// alternatively, specifying the files to transform:
{
"jest": {
"transform": {
"\\.m?js$": "rollup-jest"
},
}
}
// or with options:
// the preset enables sourcemaps by default
{
"jest": {
"transform": {
"\\.m?js$": ["rollup-jest", {"output": {"sourcemap": true}}]
},
}
}
`
Write your tests with ES modules:
`js
import path from 'path'
test('parses extname', () => {
expect(path.extname('foo.md')).toBe('.md')
})
`
Happy testing!
NOTE: To use ESM format configFile in Rollup v3, you should add --experimental-vm-module flag to run jest，eg. NODE_OPTIONS=--experimental-vm-modules npm run test
`json`
{
"jest": {
"transform": {
"\\.js$": ["rollup-jest", {"configFile": "./rollup.config.js"}]
}
}
}
rollup.config.js:
`js
import inject from '@rollup/plugin-inject'
let config = {}
if (process.env.NODE_ENV === 'test') {
config = {
plugins: [inject({React: 'react'})],
}
}
export default config
`
`json`
{
"jest": {
"transform": {
"\\.js$": [
"rollup-jest",
{"plugins": [["@rollup/plugin-inject", {"React": "react"}]]}
]
}
}
}
- useCache: boolean: Default true. Enable caching of entry module. This can mess with plugins (e.g. typescript).resolveImports: 'relative' | boolean
- : Default false. Resolve (bundle) imports, either all (incl. packages) or only relative files.args: any
- : If your config file exports a function, you can use this field to pass arguments that aren't supported in rollup's inputOptions.plugins: Plugin[]
- : Gets merged with plugins from config file. Special syntax [name, options] allows you to specify the plugin in json without require`.
- es-jest
- babel-jest
- ts-jest