I am struggling to properly stub/mock unit tests when using es6 modules along with a project with mixed .js and .ts files.
According to this post, testdouble should be able to provide the ESM mocking I need. However, it requires using --loader=testdouble to work, and I am currently using --loader=ts-node/esm. If I attempt to replace ts-node/esm, it is unable to find Typescript files:
Error [ERR_MODULE_NOT_FOUND]: Cannot find module
'/Users/repos/my-repo/src/models/connectionModel.js'
imported from
/Users/repos/my-repo/test/constants.tjs
(connectionModel is ts and imported as .js per esm convention)
Due to project requirements, I would need the project to be compiled in es6+, so removing type: module or setting module: cjs are not viable options for me.
Is there a viable way to use both loaders, or some other viable way to mock with es6?
package.json:
{
"type": "module",
"scripts": {
"test": mocha test/*.js test/*.spec.ts -r dotenv/config
}
}
tsconfig.json:
{
"compilerOptions": {
"target": "es2016",
"module": "es6,
"moduleResolution": "node16"
"allowJs": true,
"esModuleInterop": true
},
"ts-node": {
"esm": true
}
"include": [
"./src/**/*",
"test/**/*/.ts",
"test/**/*.js"
}
}
.mocharc.json: (grabbing from this answer)
{
"node-option": [
"experimental-specifier-resolution=node",
"loader=ts-node/esm"
]
}
Related
I'm trying to import JSON in nodejs.
// tsconfig.json
...
"lib": ["es2022"],
"target": "es2022",
"module": "nodenext",
"moduleResolution": "node",
...
"resolveJsonModule": true,
...
// .swcrc.json
...
"target": "es2022",
...
"module": {
"type": "nodenext",
...
When I then compile it and run "start": "NODE_ENV=production node --es-module-specifier-resolution=node --experimental-json-modules --no-warnings lib/index.js" I get TypeError [ERR_IMPORT_ASSERTION_TYPE_MISSING]: Module "file:///path/to/data.json" needs an import assertion of type "json".
I then add:
import data from './data.json' assert {type: 'json'}
console.log(data)
I then open up the compiled code and I can see:
import data from"./data.json";console.log(data);
//# sourceMappingURL=index.js.map
At this point I thought maybe it's SWC not compiling the assertation?
I then run tsc --emitDeclarationsOnly and I get Import assertions are not allowed on statements that transpile to commonjs 'require' calls. At this point I have no idea why on earth commonjs has anything to do with it, I'm not using commonjs anywhere am I?
Also I'm using node 18.
What am I doing wrong? I am simply trying to import that json.
Edit: Okay so the reason TS was breaking was because of missing "include": ["src/**/*.ts", "src/**/*.json", "types.d.ts"],. After adding that it now works. Unfortunately SWC is still giving the same error so I cannot run it.
Finally figured it out. There's an experimental option in .swcrc.json that allows you to tell it to keep the assertations.
// .swcrc.json
...
"jsc": {
"experimental": {
"keepImportAssertions": true
}
}
I'm trying to write a simple jest test for a 3rd party package were using that only exports an ES module. It's a wrapper around an http server.
Here is a test repo I setup (just run yarn && yarn jest to reproduce): https://github.com/jamesopti/hocuspocus-testing
No matter what config I experiment with, I still get this error when trying to run it:
Must use import to load ES Module: /Users/j/hocuspocus-testing/node_modules/#hocuspocus/server/dist/hocuspocus-server.esm.js
> 1 | import { Server, Hocuspocus } from '#hocuspocus/server'
| ^
2 | import * as request from 'supertest'
3 |
4 | describe('Server (e2e)', () => {
Things I've tried already:
The Jest instructions on ES modules: https://jestjs.io/docs/ecmascript-modules
In Jest configuration using transformIgnorePatterns
transformIgnorePatterns: ['node_modules/(?!#hocuspocus/)']
Using Babel via babel-jest
modifying transform setup in Jest configuration as '^.+\.jsx?$': 'babel-jest', '^.+\.tsx?$': 'ts-jest'
Ran into the error You appear to be using a native ECMAScript module configuration file, which is only supported when running Babel asynchronously.
Using .babel.config.js instead of .babelrc.js
Any ideas what I'm missing here? I thought this would be straightforward
[EDIT 1] - Added tsconfig.json and a working src/index.ts file to the example repo.
So for anyone still hitting this, ESM configuration explained in this section of documentation :
https://kulshekhar.github.io/ts-jest/docs/guides/esm-support
{
// [...]
"jest": {
"extensionsToTreatAsEsm": [".ts"],
"globals": {
"ts-jest": {
"useESM": true
}
}
}
}
JAN 2023: ES2022, TypeScript 4.9.4, jest 29.3.1, ts-jest 29.0.3
This is what worked for me, after 2 hours of frustration.
I used this configuration in jest.config.ts:
import type { JestConfigWithTsJest } from 'ts-jest'
const config: JestConfigWithTsJest = {
extensionsToTreatAsEsm: ['.ts'],
verbose: true,
preset: 'ts-jest/presets/default-esm',
testEnvironment: 'node',
transform: {
'^.+\\.(ts|tsx)?$': ['ts-jest', { useESM: true }]
},
testPathIgnorePatterns: ['./dist']
}
export default config
Change the test script in package.json to:
I use pnpm. Change to npx jest with npm,
or yarn exec with yarn
...
"scripts": {
...
"test": "NODE_OPTIONS=--experimental-vm-modules pnpm exec jest",
...
}
...
tsconfig.json:
{
"compilerOptions": {
"rootDirs": ["src"],
"outDir": "dist",
"lib": ["ES2022"],
"target": "ES2022",
"module": "ES2022",
"composite": true,
"moduleResolution": "node",
"declaration": true,
"declarationMap": true,
"incremental": true,
"esModuleInterop": true,
"types": ["jest", "node", "#types/jest"],
"sourceMap": true
},
"ts-node": {
"esm": true,
"experimentalSpecifierResolution": "node"
},
"include": ["./src/**/*", "./tests/**/*"]
}
See this (rather confusing) documentation for reference:
https://kulshekhar.github.io/ts-jest/docs/guides/esm-support/
You don't have a tsconfig.json file that specifies module. Therefore it uses the default, where it transpiles all your modules to CommonJS syntax, which uses require.
If you actually look at your dist/hocuspocus-server.esm.js, you should see it using require over the ESM import syntax.
I was having the same problem with my svelte app and testing. I ultimately traced it to having a jest.config.js and a jest.config.json in my root folder. It seems that jest does not have automatic config file resolution and was using a default configuration instead of either of my specified configurations.
Although TS-Node started the ECMAScript modules support, it has a lot of limitations and below example:
import { assert as Assert } from "chai";
describe("firstTest", (): void => {
it("", (): void => {
Assert.isTrue(true);
});
});
does not work with next settings:
tsconfig.json
{
"compilerOptions": {
"target": "ES2020",
"module": "ES2020",
"moduleResolution": "node",
"strict": true,
"allowSyntheticDefaultImports": true,
"experimentalDecorators": true,
"skipLibCheck": true,
"baseUrl": "./",
"paths": {},
"noUnusedParameters": true,
"noImplicitReturns": true
}
}
.mocharc.yaml
extension:
- ts
spec: "**/*.test.ts"
require:
- ts-node/register
- tsconfig-paths/register
Error:
import { assert as Assert } from "chai";
^^^^^^
SyntaxError: Cannot use import statement outside a module
I need the ECMAScript modules because the Webpack dynamic loading does not work with CommonJS modules. So the conceptual solution is create the additional tsconfig.json for TSNode or pass modules type via console. It's has been documented how to do it for TSNode, but here I don't execute TSNode directly - I launch the Mocha via IntelliJ IDEA:
IntelliJ IDEA and, I suppose, all IDEs of this family including WebStorm generates the below command (added the line breaks):
"C:\Program Files\nodejs\node.exe"
"D:\XXX\MyProject\node_modules\mocha\bin\mocha" --require ts-node/register --ui bdd --reporter C:\Users\XXX\AppData\Local\JetBrains\Toolbox\apps\IDEA-U\ch-0\203.7148.57\plugins\NodeJS\js\mocha-intellij\lib\mochaIntellijReporter.js
"D:\XXX\MyProject\Test\Test.test.ts" --grep "^firstTest "
Now how to set CommonJS modules type?
According to ts-node's documentation (search for IntelliJ), you can create an alternative tsconfig.json (containing the option "module": "CommonJS") and enforce it for Mocha tests using environment variable TS_NODE_PROJECT. In the configuration corresponding to your Mocha testing, in the Environment variables section, you set this variable to the pathname of this alternative tsconfig.json. Note, multiple tsconfig.json files can use one common "base" file and extend/partially override it (see).
I would import class in nodejs and use it in app.ts
var nano = require("nano");
import { EnvConfig } from './envConfig.service';
let config = new EnvConfig();
const dbCredentials: any = config.appEnv.getServiceCreds('dataservices');
export const nanodb = nano({
url: dbCredentials.url,
});
export const nanodbCockpitLight = nanodb.use('data');
console.log(dbCredentials);
When I try to compile I get this error.
import { EnvConfig } from './envConfig.service';
^
SyntaxError: Unexpected token {
I have created the tsconfig file :
{
"compilerOptions": {
"module": "commonjs",
"declaration": false,
"noImplicitAny": false,
"removeComments": true,
"noLib": false,
"allowSyntheticDefaultImports": true,
"emitDecoratorMetadata": true,
"experimentalDecorators": true,
"target": "es6",
"sourceMap": true,
"allowJs": true,
"outDir": "./dist",
//"baseUrl": "src" // Attention !! nécessite l'utilisation d'un loader de module node pour fonctionner sur node
},
"include": ["src/**/*"],
"exclude": ["node_modules", "**/*.spec.ts"]
}
I get this warning
No inputs were found in config file 'c:/Users/EHHD05911.COMMUN/Documents/cockpitLight/DB mananger/tsconfig.json'. Specified 'include' paths were '["src//"]' and 'exclude' paths were '["node_modules","/.spec.ts"]'
You cannot run node app.ts file directly that won't work
You need transpiler like babel js or typescript compiler tsc so first transpile to js file and then run node app.js
You're using .js extension, you need .ts extension, e.g.: app.ts instead of app.js.
Make sure you have typescript either in npm global or in dev dependencies.
I suspect whatever you're importing has typescript syntax (strong typing and such), and so running node directly won't work. You need to run tsc first, which will transpile everything to javascript in a dist folder, and then run node dist/app.js.
This is a bit cumbersome though, which is why there is ts-node. It's exactly what it sounds like, a node REPL for typescript. You should be able to run ts-node src/app.ts.
import { something } is a typescript syntax, it won't work in a .js file. That is a separate language. Try using require instead.
Use babel js which is a toolchain that is mainly used to convert ECMAScript 2015+ code into a backwards compatible version of JavaScript in current and older browsers or environments.
package.json
"dependencies": {
"#babel/polyfill": "^7.0.0",
}
"babel": {
"presets": [
"#babel/preset-env"
]
},
"scripts": {
"start": "server.js --exec babel-node",
}
https://babeljs.io/docs
This will enable/resolve your import statements.
I'm using Jest to test my React app.
Recently, I added DeckGL to my app. My tests fail with this error:
Test suite failed to run
/my_project/node_modules/deck.gl/src/react/index.js:21
export {default as DeckGL} from './deckgl';
^^^^^^
SyntaxError: Unexpected token export
at ScriptTransformer._transformAndBuildScript (node_modules/jest-runtime/build/script_transformer.js:318:17)
at Object.<anonymous> (node_modules/deck.gl/dist/react/deckgl.js:9:14)
at Object.<anonymous> (node_modules/deck.gl/dist/react/index.js:7:15)
This looks like an issue with Jest transforming a node module before running it's tests.
Here is my .babelrc:
{
"presets": ["react", "es2015", "stage-1"]
}
Here is my jest setup:
"jest": {
"testURL": "http://localhost",
"setupFiles": [
"./test/jestsetup.js"
],
"snapshotSerializers": [
"<rootDir>/node_modules/enzyme-to-json/serializer"
],
"moduleDirectories": [
"node_modules",
"/src"
],
"moduleNameMapper": {
"\\.(css|scss)$": "<rootDir>/test/EmptyModule.js"
}
},
I seem to have the correct things necessary to transform export {default as DeckGL }. So any ideas whats going wrong?
This means, that a file is not transformed through TypeScript compiler, e.g. because it is a JS file with TS syntax, or it is published to npm as uncompiled source files. Here's what you can do.
Adjust your transformIgnorePatterns allowed list:
{
"jest": {
"transformIgnorePatterns": [
"node_modules/(?!#ngrx|(?!deck.gl)|ng-dynamic)"
]
}
}
By default Jest doesn't transform node_modules, because they should be valid JavaScript files. However, it happens that library authors assume that you'll compile their sources. So you have to tell this to Jest explicitly. Above snippet means that #ngrx, deck and ng-dynamic will be transformed, even though they're node_modules.
And if you are using 'create-react-app', it won't allow you to specify 'transformIgnorePatterns' via Jest property in package.json
As per this https://github.com/facebook/create-react-app/issues/2537#issuecomment-390341713
You can use CLI as below in your package.json to override and it works :
"scripts": {
"test": "react-scripts test --transformIgnorePatterns \"node_modules/(?!your-module-name)/\"",
},
This is because Node.js cannot handle ES6 modules.
You should transform your modules to CommonJS therefore.
Babel 7 >=
Install
npm install --save-dev #babel/plugin-transform-modules-commonjs
And to use only for test cases add to .babelrc,
Jest automatically gives NODE_ENV=test global variable.
"env": {
"test": {
"plugins": ["#babel/plugin-transform-modules-commonjs"]
}
}
Babel 6 >=
npm install --save-dev babel-plugin-transform-es2015-modules-commonjs
to .babelrc
"env": {
"test": {
"plugins": ["transform-es2015-modules-commonjs"]
}
}
Jest by default won't compile files in the node_modules directory.
transformIgnorePatterns [array]
Default: ["/node_modules/"]
An array of regexp pattern strings that are matched against all source
file paths before transformation. If the test path matches any of the
patterns, it will not be transformed.Default: ["/node_modules/"]
DeckGL seems to be in ES6, to make jest able to read it, you need to compile this as well.
To do that, just add an exception for DeckGL in the transformignorePatterns
"transformIgnorePatterns": ["/node_modules/(?!deck\.gl)"]
https://facebook.github.io/jest/docs/en/configuration.html#transformignorepatterns-array-string
I was having this issue with a monorepo. A package in the root node_modules was breaking my tests. I fixed by changing my local .babelrc file to babel.config.js. Explanation: https://github.com/facebook/jest/issues/6053#issuecomment-383632515
It was work around #1 on this page that fixed it for me though workaround #2 on that page is mentioned in above answers so they may also be valid.
"Specify the entry for the commonjs version of the corresponding package in the moduleNameMapper configuration"
jest.config.js
moduleNameMapper: {
"^uuid$": require.resolve("uuid"),
"^jsonpath-plus$": require.resolve("jsonpath-plus")
...
In my case I use this config in the file package.json:
"jest": {
"transformIgnorePatterns": [
"!node_modules/"
]
}
This code worked for me
// .babelrc
{
"presets": [
["env", {
"modules": "commonjs", // <- Check and see if you have this line
"targets": {
"browsers": ["> 1%", "last 2 versions", "not ie <= 8"]
}
}],
"stage-2"
],
"plugins": ["transform-vue-jsx", "transform-runtime"],
"env": {
"test": {
"presets": ["env", "stage-2"],
"plugins": ["transform-vue-jsx", "transform-es2015-modules-commonjs", "dynamic-import-node"]
}
}
}
jest understands commonJs so it needs babel to transform the code for it before use. Also jest uses caching when running code. So make sure you run jest --clearCache before running jest.
Tested Environment:
Node v8.13.0
Babel v6+
Jest v27
I'm using a monorepo (it contains multiple packages for the frontend and backend).
The package I'm testing imports a file from another package that uses the dependency uuid.
All the files are in Typescript (not Javascript).
The package I'm testing has a tsconfig file for testing only, called tsconfig.test.json. It has the properties commonjs and allowJs. Adding allowJs solves the problem when importing uuid, I don't know why.
{
"extends": "./tsconfig.json",
"compilerOptions": {
"outDir": "../../dist/out-tsc",
"module": "commonjs",
"types": [
"jest",
"node"
],
// Necessary to import dependency uuid using CommonJS
"allowJs": true
},
"include": [
"jest.config.ts",
"**/*.test.ts",
"**/*.d.ts"
]
}
I was upgrading a project that uses a version of babel that reads the config from .babelrc, when I upgraded to a newer version I read:
https://babeljs.io/docs/en/configuration#whats-your-use-case
What's your use case?
You are using a monorepo?
You want to compile node_modules?
babel.config.json is for you!
On top of:
{
"jest": {
"transformIgnorePatterns": [
"node_modules/(?!(module))"
]
}
}
I renamed .babelrc to babel.config.json too.
I had the same error of importing dataSet from vis-data.js library
import { DataSet } from 'vis-data/esnext';
So I just removed /esnext from the path and now it works:
import { DataSet } from 'vis-data';