I am looking to be able to use webpack aliases to resolve imports when using jest, and optimally, reference the webpack.aliases to avoid duplication.
Jest conf:
"jest": {
"modulePaths": ["src"],
"moduleDirectories": ["node_modules"],
"moduleNameMapper": {
"^@shared$": "<rootDir>/shared/",
"^@components$": "<rootDir>/shared/components/"
}
},
Webpack aliases:
exports.aliases = {
'@shared': path.resolve(paths.APP_DIR, 'shared'),
'@components': path.resolve(paths.APP_DIR, 'shared/components'),
};
Imports:
import Ordinal from '@shared/utils/Ordinal.jsx';
import Avatar from '@components/common/Avatar.jsx';
For some reason the @ causes issues, so when removed (in both alias and import), it can find shared but components still cannot be resolved.
FAIL src/shared/components/test/Test.spec.jsx
● Test suite failed to run
Cannot find module '@shared/utils/Ordinal.jsx' from 'Test.jsx'
I have tried using jest-webpack-alias, babel-plugin-module-resolver and the Jest/Webpack docs
This seems to have been fixed.
Below is a working setup:
Versions
"jest": "~20.0.4"
"webpack": "^3.5.6"
package.json
"jest": {
"moduleNameMapper": {
"^@root(.*)$": "<rootDir>/src$1",
"^@components(.*)$": "<rootDir>/src/components$1",
}
}
webpack.shared.js
const paths = {
APP_DIR: path.resolve(__dirname, '..', 'src'),
};
exports.resolveRoot = [paths.APP_DIR, 'node_modules'];
exports.aliases = {
'@root': path.resolve(paths.APP_DIR, ''),
'@components': path.resolve(paths.APP_DIR, 'components'),
};
Since I had the same problem before I read again, and this time more carefully the documentation. Correct config should be:
"jest": {
"moduleNameMapper": {
"^@shared(.*)$": "<rootDir>/shared$1",
"^@components(.*)$": "<rootDir>/shared/components$1"
}
},
Using: "jest": "^26.5.3", and "webpack": "4.41.5",
I was able to properly match my webpack/typescript aliases in the jest.config.js with this pattern:
Webpack config:
module.exports = {
// the rest of your config
resolve: {
alias: {
'components': path.resolve(__dirname, 'js/app/components'),
'modules': path.resolve(__dirname, 'js/app/modules'),
'types': path.resolve(__dirname, 'js/types'),
'hooks': path.resolve(__dirname, 'js/app/hooks'),
'reducers': path.resolve(__dirname, 'js/app/reducers'),
'__test-utils__': path.resolve(__dirname, 'js/app/__test-utils__')
}
},
}
Jest.config.js:
moduleNameMapper: {
'^types/(.*)$': '<rootDir>/js/types/$1',
'^components/(.*)$': '<rootDir>/js/app/components/$1',
'^modules/(.*)$': '<rootDir>/js/app/modules/$1',
'^hooks/(.*)$': '<rootDir>/js/app/hooks/$1',
'^reducers/(.*)$': '<rootDir>/js/app/reducers/$1',
'^__test-utils__/(.)$': '<rootDir>/js/app/__test-utils__/$1'
}
Here's an explanation of the symbols:
(.*)$: capture whatever comes after the exact match (the directory)$1: map it to this value in the directory I specify.and tsconfig.json:
"paths": {
"config": ["config/dev", "config/production"],
"components/*": ["js/app/components/*"],
"modules/*": ["js/app/modules/*"],
"types/*": ["js/types/*"],
"hooks/*": ["js/app/hooks/*"],
"reducers/*": ["js/app/reducers/*"],
"__test-utils__/*": ["js/app/__test-utils__/*"]
}