Does the testing framework Jest have an ultimate after all callback? A callback that is only called once after all the other test files pass or fail? Or is there a way to achieve this with afterall? I'd like to run a generic teardown that will teardown the environment that is used by all the test files (that is setup before any of the tests are run).
Jest supports globalTeardown
and you can use it in CLI
jest --globalTeardown="<rootDir>/src/jest/teardown.js"
or in jest.config.json
{
"preset": "ts-jest",
"globalSetup": "<rootDir>/src/jest/setup.js",
"globalTeardown": "<rootDir>/src/jest/teardown.js"
}
or in package.json
{
// .... rest of the package json
"jest": {
"preset": "ts-jest",
"globalSetup": "<rootDir>/src/jest/setup.ts",
"globalTeardown": "<rootDir>/src/jest/teardown.ts"
}
}
Related
I just started testing with Jest for the first time. This is a very simple Typescript utils library. I basically followed the installation guide, and my first two tests passed. Yay. The next function I tested imported a few functions from lodash-es, and failed (error below).
This is how I added jest:
pnpm add -D jest ts-jest #types/jest
pnpx ts-jest config:init
My jest.config.js file, as generated by pnpx ts-jest config:init, except that I had to change the second line to export default, because my package.json specifies this to be a module.
/** #type {import('ts-jest').JestConfigWithTsJest} */
export default {
preset: 'ts-jest',
testEnvironment: 'node',
transformIgnorePatterns: [
"node_modules/(?!(lodash-es)/)"
],
moduleNameMapper: {
'lodash-es': '../node_modules/lodash-es/lodash.js',
},
}
I've tried adding transformIgnorePatterns and moduleNameMapper, based on others with similar issues. But no luck.
The error message:
D:\Dev\NodeJs\vexna\packages\util>pnpm test
> #vexna/util#1.0.0 test D:\Dev\NodeJs\vexna\packages\util
> jest
PASS test/reverseString.test.ts
PASS test/hash.test.ts
FAIL test/uid.test.ts
● Test suite failed to run
Jest encountered an unexpected token
Jest failed to parse a file. This happens e.g. when your code or its dependencies use non-standard JavaScript syntax, or when Jest is not configured to support such syntax.
Out of the box Jest supports Babel, which will be used to transform your files into valid JS based on your Babel configuration.
By default "node_modules" folder is ignored by transformers.
Here's what you can do:
• If you are trying to use ECMAScript Modules, see https://jestjs.io/docs/ecmascript-modules for how to enable it.
• If you are trying to use TypeScript, see https://jestjs.io/docs/getting-started#using-typescript
• To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
• If you need a custom transformation specify a "transform" option in your config.
• If you simply want to mock your non-JS modules (e.g. binary assets) you can stub them out with the "moduleNameMapper" config option.
You'll find more details and examples of these config options in the docs:
https://jestjs.io/docs/configuration
For information about custom transformations, see:
https://jestjs.io/docs/code-transformation
Details:
D:\Dev\NodeJs\vexna\node_modules\.pnpm\lodash-es#4.17.21\node_modules\lodash-es\lodash.js:10
export { default as add } from './add.js';
^^^^^^
SyntaxError: Unexpected token 'export'
> 1 | import { now, random, padStart, padEnd } from "lodash-es"
| ^
2 | import { reverseString } from "./reverseString"
3 |
4 |
at Runtime.createScriptFromCode (../../node_modules/.pnpm/jest-runtime#29.4.1/node_modules/jest-runtime/build/index.js:1598:14)
at Object.<anonymous> (src/uid.ts:1:1)
at Object.<anonymous> (test/uid.test.ts:1:1)
Test Suites: 1 failed, 2 passed, 3 total
Tests: 2 passed, 2 total
Snapshots: 0 total
Time: 3.494 s
Ran all test suites.
ELIFECYCLE Test failed. See above for more details.
A few things, this project exists in pnpm monorepo, in case it matters.
This is the package.json:
{
"name": "#vexna/util",
"version": "1.0.0",
"description": "Generic utilities, uses lodash",
"private": true,
"type": "module",
"main": "dist/index.js",
"types": "dist/index.d.ts",
"sideEffects": false,
"scripts": {
"build": "rimraf dist && tsc && rollup -c rollup.config.js",
"test": "jest",
"pretest": "npm run build"
},
"devDependencies": {
"#rollup/plugin-typescript": "^11.0.0",
"#types/jest": "^29.4.0",
"#types/lodash-es": "^4.17.6",
"jest": "^29.4.1",
"lodash-es": "^4.17.21",
"rimraf": "^4.1.2",
"rollup": "^3.12.1",
"ts-jest": "^29.0.5",
"typescript": "^4.9.5"
},
"files": [
"dist"
],
"peerDependencies": {
"lodash": "^4.17.21"
}
}
I suspect that perhaps Jest goes off into the boonies because I have externalized lodash?
Or perhaps I should add Babel? But could just as well be something else completely.
Some help is much appreciated!
Use Vitest.
Jest is quite painful to install correctly, whereas Vitest works out of the box without any config. This is my personal experience. It took me days to get Jest to sort-of work. I had Vitest working immediately after installation.
I don't want to hate on Jest, I actually think it's a wonderful and intuitive testing tool. But ultimately Vitest "Just Works" (tm), and you can use the same simple Jest style API we all have come to love.
Steps:
pnpm remove jest ts-jest #types/jest
pnpm add -D vite vitest
Delete jest.config.js, and create vite.config.ts:
/// <reference types="vitest" />
import { defineConfig } from 'vite'
export default defineConfig({
test: {
/* for example, use global to avoid globals imports (describe, test, expect): */
// globals: true,
},
})
Add to your tests:
import { assert, expect, test } from 'vitest'
Update your package.json:
"test": "vitest",
I'm just trying to run some integration tests on a nestjs app, but I'm getting the following error:
SyntaxError: Cannot use import statement outside a module
I spent a lot of time on this problem that should be easy to fix but I can't deal with it.
This problem occurs with #nestjs/axios lib which uses ESM instead of CommonJs. After doing some research, I saw that theoretically I should run the tests with this command:
yarn node --experimental-vm-modules $(yarn bin jest)
But nothing i do works
I also don't understand why this file is being matched since it is in node_modules
Can someone help me?
My Jest config:
"jest": {
"moduleFileExtensions": [
"js",
"json",
"ts"
],
"rootDir": "",
"preset": "ts-jest",
"testRegex": ".spec.ts$",
"transform": {
"^.+\\.(t|j)s$": "ts-jest"
},
"coverageDirectory": "./coverage",
"testEnvironment": "node",
"globalSetup": "<rootDir>/tests/jest.setup.ts",
"globalTeardown": "<rootDir>/tests/jest.teardown.ts"
}
My versions:
"#nestjs/axios": "^1.0.1",
"#types/jest": "^24.0.18",
"jest": "^26.0.0",
"ts-jest": "^26.5.5",
"typescript": "^4.2.3"
I've already tried putting node_modules (which is already jest's default behavior) in the transformIgnorePatterns setting, but it's not working.
The lib I'm having this error is an internal lib (node_modules/#bank/auth/node_modules/#nestjs/axios/node_modules/axios/index.js:1), could it be the reason for the problem?
This has to do with jest and ts-jest seeing the library as an ESM module due to how the package.json is set up. You should be able to add this to your jest config and have no issues.
moduleNameMapper: {
'^axios$': require.resolve('axios'),
},
This should force jest to resolve the library correctly from node_modules
I am looking for a way to exclude entire folders/files from my testing coverage with Jest. I have gone through the official Jest documentations several times, but have been unable to get it to work. I've come to the conclusion that maybe my jest.config.js isn't being picked up, because no matter what changes I make to the collectCoverageFrom or testPathIgnorePatterns fields, the test coverage return does not change, and it includes everything, even the things I am trying to exclude. Here is my test coverage script in the package.json:
"test-coverage": "npm test --config='jest.config.js' --coverage "
and here is my jest.config.js:
module.exports = {
roots: ['<rootDir>', '<rootDir>/src', '<rootDir>/tests'],
testEnvironment: 'jsdom',
testPathIgnorePatterns: ['/node_modules/'],
collectCoverage: true,
collectCoverageFrom: ['./src/**/*.{js, jsx}', '!**/node_modules/**', '!**/vendor/**'],
coverageDirectory: './coverage',
}
For the files I am excluding, I am just using this format: !src/folder/file.js as per the official jest
documentation.
Any help appreciated.
Things I did to troubleshoot:
I added the path to the Jest config into the test-coverage command, but that was unsuccessful.
I have set the collectCoverage field above to true, no success.
I added the jest config to the actual package.json, but even that
did not change anything. Here is the format for it inside my
package.json:
"jest": {
"roots": ["<rootDir>", "<rootDir>/src","<rootDir>/tests"],
"testEnvironment": "jsdom",
"testPathIgnorePatterns": ["/node_modules/"],
"collectCoverage": true,
"collectCoverageFrom": ["./src/**/*.{js,jsx}","!**/node_modules/**","!**/vendor/**"],
"coverageDirectory": "./coverage"
}
Is it possible to test ES6 Modules with Jest without esm or babel? Since node v13 supports es6 natively have tried:
//package.json
{
…
"type": "module"
…
}
//__tests__/a.js
import Foo from '../src/Foo.js';
$ npx jest
Jest encountered an unexpected token
…
Details:
/home/node/xxx/__tests__/a.js:1
import Foo from '../src/Foo.js';
^^^^^^
SyntaxError: Cannot use import statement outside a module
When babel is added a transpiler, it works, but can es6 modules be used natively as well?
Yes, it is possible from jest#25.4.0. From this version, there is a native support of esm, so you will not have to transpile your code with babel anymore.
It is not documented yet, but according to this issue you have to do 3 easy steps to achieve that (At the time of writing this answer):
Make sure you don't transform away import statements by setting transform: {} in your jest config file
Run node#^12.16.0 || >=13.2.0 with --experimental-vm-modules flag
Run your test with jest-environment-node or jest-environment-jsdom-sixteen.
So your jest config file should contain at least this:
export default {
testEnvironment: 'jest-environment-node',
transform: {}
...
};
And to set --experimental-vm-modules flag, you will have to run Jest from package.json as follows (I hope this will change in the future):
"scripts": {
"test": "node --experimental-vm-modules node_modules/jest/bin/jest.js"
}
I hope, this answer was helpful to you.
Note that this is is still experimental, but we have documented how to test this, so there's hopefully less confusion.
https://jestjs.io/docs/en/ecmascript-modules
The steps in https://stackoverflow.com/a/61653104/1850276 are correct
I followed the tips provided in the accepted answer, but I added the property "type": "module" in my package.json in order to jest works properly. This is what I done:
In package.json:
"devDependencies": {
"jest": "^26.1.0",
"jest-environment-jsdom-sixteen": "^1.0.3",
"jest-environment-node": "^26.1.0"
},
"scripts": {
"test": "node --experimental-vm-modules node_modules/jest/bin/jest.js"
},
"type": "module",
"jest": {
"transform": {},
"testEnvironment": "jest-environment-jsdom-sixteen"
}
To run jest from "jest" extension in VSCode with "--experimental-vm-modules" flags, put this config in your global or workspaces settings.json:
"jest.nodeEnv": {
"NODE_OPTIONS": "--experimental-vm-modules"
}
In addition to #Radovan Kuka's answer, here's how to run Jest with ES modules, using npx:
"test:monitoring": "npx --node-arg=--experimental-vm-modules jest -f monitoring.test.js --detectOpenHandles",
The benefit is that one doesn't need to provide the absolute node_modules path.
Without Babel, here's a complete, minimal example that works on recent Jest versions. Run with npm test.
$ tree -I node_modules
.
├── package.json
├── src
│ └── foo.js
└── __tests__
└── foo.spec.js
package.json:
{
"type": "module",
"scripts": {
"test": "NODE_OPTIONS=--experimental-vm-modules jest"
},
"devDependencies": {
"jest": "^29.3.1"
}
}
src/foo.js:
export const bar = () => 42;
__tests__/foo.spec.js:
import {bar} from "../src/foo";
describe("foo.bar()", () => {
it("should return 42", () => {
expect(bar()).toBe(42);
});
});
The secret sauce is in the package.json: "type": "module" and NODE_OPTIONS=--experimental-vm-modules jest.
If you want to add a mock, it's a bit complicated. See this answer.
I am writing integration tests for a CLI. All the unit tests are written using Jest as out-of-the-box it produces code coverage without any configuration, but unfortunately it does not instrument sub-processes, for example executed via Node's spawn and fork commands.
I have tried to introduce nyc into the mix as suggested in this comment on a GitHub issue however it has not worked for me.
I have played with various configurations (based on the initial aforementioned suggestion and also ideas from these issues: 1, 2), however either I get no coverage statistics at all or only coverage for my unit tests, not the integration tests that spawn sub-processes.
The relevant parts of my package.json which configures nyc and Jest:
"scripts": {
"test": "cross-env NODE_ENV=test nyc --clean jest --coverage",
},
"jest": {
"verbose": true,
"testURL": "http://localhost/",
"globalSetup": "./jest.setup.js",
"transform": {
"^.+\\.js$": "babel-jest"
},
"collectCoverage": false
},
"nyc": {
"include": [
"packages/*/src/**/*.js"
],
"reporter": [
"html"
]
},
I am using execa to run the sub-processes and do so as follows:
await execa("nyc --reporter none node", args);