So i just started learning about Test Driven Developement and as an example i was asked to run the command npm test helloWorld.spec.js in the terminal but i got this error :
> javascript-exercises#1.0.0 test
> jest "helloWorld.spec.js"
'jest' n’est pas reconnu en tant que commande interne
ou externe, un programme exécutable ou un fichier de commandes.
// in english jest isn't recognized as an internal command or external
I'm working on windows and the only thing i have installed is node so what do i have to do?
Choose one of the following methods
1) Install globally
You need to install jest globally:
npm install jest -g
Note: You will have to call it as jest something.spec.js in your cli or specify a test command in your package.json.
2) Install locally
Install jest locally with npm install jest -D.
You can use a script in your package.json called test which would be "test": "jest".
If any of the above don't work, try reinstalling jest.
If it still doesn't work, try removing node_modules and npm cache clean --force and npm install
3) Config file
If you already have jest installed but it's not working, you can use a config file to track files based on regex pattern (you can do a lot more if you check out the docs).
The following part is from the docs:
Jest's configuration can be defined in the package.json file of your project, or through a jest.config.js, or jest.config.ts file or through the --config <path/to/file.js|ts|cjs|mjs|json> option. If you'd like to use your package.json to store Jest's config, the "jest" key should be used on the top level so Jest will know how to find your settings:
{
"name": "my-project",
"jest": {
"verbose": true
}
}
Or through JavaScript:
// Sync object
/** #type {import('#jest/types').Config.InitialOptions} */
const config = {
verbose: true,
};
module.exports = config;
// Or async function
module.exports = async () => {
return {
verbose: true,
};
};
Or through TypeScript (if ts-node is installed):
import type {Config} from '#jest/types';
// Sync object
const config: Config.InitialOptions = {
verbose: true,
};
export default config;
// Or async function
export default async (): Promise<Config.InitialOptions> => {
return {
verbose: true,
};
};
When using the --config option, the JSON file must not contain a "jest" key:
{
"bail": 1,
"verbose": true
}
Regex options
testMatch [array]
(default: [ "**/__tests__/**/*.[jt]s?(x)", "**/?(*.)+(spec|test).[jt]s?(x)" ])
The glob patterns Jest uses to detect test files. By default it looks for .js, .jsx, .ts and .tsx files inside of __tests__ folders, as well as any files with a suffix of .test or .spec (e.g. Component.test.js or Component.spec.js). It will also find files called test.js or spec.js.
Note: Each glob pattern is applied in the order they are specified in the config. (For example ["!**/__fixtures__/**", "**/__tests__/**/*.js"] will not exclude __fixtures__ because the negation is overwritten with the second pattern. In order to make the negated glob work in this example it has to come after **/__tests__/**/*.js.)
testRegex [string | array]
Default: (/__tests__/.*|(\\.|/)(test|spec))\\.[jt]sx?$
The pattern or patterns Jest uses to detect test files. By default it looks for .js, .jsx, .ts and .tsx files inside of \_\_tests\_\_ folders, as well as any files with a suffix of .test or .spec (e.g. Component.test.js or Component.spec.js). It will also find files called test.js or spec.js. See also testMatch [array], but note that you cannot specify both options.
Related
I have built a library that I want to use in a Next.JS project. Within this library a certain dependency is using an import via a string passed into a require statement within the source code where the import is taking place. This is causing webpack to not recognize the import. I don't want to change code within any node_modules as this is not a preferred approach but how can I ensure that my project using the library I built is able to compile and run?
Within file_using_string_passed_into_require_to_get_import.js:
let importName = "./potential_import_A.js"
if(condition){
importName = "./potential_import_B.js"
}
module.exports = require(importName)
This is the folder structure:
Project/
| node_modules
| my-library
| node_modules
| library-dependency
| file_using_string_passed_into_require_to_get_import.js
| potential_import_A.js
| potential_import_B.js
To create a local (unpublished) library package
Create a 'my-library' folder (outside your current project dir).
Do npm init (Folder must include the 'package.json' )
Include source code (potential_import_A), exporting any desired functions.
In the actual project folder:
cd into the folder of the project that needs to use your library.
Run npm install --save local/path/to/my-library.
The --save will add the package to your dependencies in the project's package.json file, as it does with 3rd party published packages. It will also add a copy of the source code to the node modules folder of the project, as always.
Importing your new library:
import/require the package as you would normally, from any project.
For example
import { myFunction } from "my-library"
I got it to work by excluding node_modules from the webpack build. Since I am using Next.JS this is within my next.config.js
const nodeExternals = require('webpack-node-externals');
module.exports = {
webpack: (
config,
{
buildId, dev, isServer, defaultLoaders, nextRuntime, webpack,
},
) => {
if (isServer) {
config.target = 'node';
config.node = {
__dirname: true,
global: true,
__filename: true,
};
config.externals = [nodeExternals()], // in order to ignore all modules in node_modules folder
config.externalsPresets = {
node: true, // in order to ignore built-in modules like path, fs, etc.
};
}
return config;
},
};
I'm new to Node and JS Testing. I have a web applications w/ Webpack as a bundler. I have some entry point JS's which are included into the page. The entry points are using module files like this:
export default function() {
...
}
Now I would like to Unit test this module. I have picked up Mocha but it is not critical to me. Could be Jest or anything else.
I wrote a very simple test.js like this. It it not doing anything but tests if the entire setup works:
import foo from '../js/someModuleOfMine'
const assert = require('assert')
describe('Test Suite', () => {
it('should at least run', () => {
assert.equal(true, true)
})
})
executing mocha from CLI gives me this error:
import foo from '../js/someModuleOfMine'
^^^^^^
SyntaxError: Cannot use import statement outside a module
Adhering to some advises I have tired to add "type": "module" to my package.json but it only changed error to something even more obscure:
Error: Not supported
I am definitely missing something obvious but I cannot comprehend what.
Not sure if it will help the OP, but I had the same problem and it was due to typescript. I solved in this way:
install ts-node:
npm install ts-node --save-dev
add the require line in the mocha config (I have it in the package.json, but one can also have it in the .mocharc.json file):
"mocha": {
"spec": "./**/*test.ts",
"ignore": "./node_modules/**",
"require": "ts-node/register/files",
"timeout": 20000
}
For some reason, my jest configuration doesn't work with the latest version of d3-path#3.0.1. It worked fine with version 2.0.0. I guess it has something to do with d3-path switching to ESM, but I was already using ES6 in my own code, so I don't get why it suddenly doesn't work anymore. I have the following packages installed:
"dependencies": {
"d3-path": "^3.0.1"
},
"devDependencies": {
"#babel/core": "^7.15.8",
"#babel/preset-env": "^7.15.8",
"babel-jest": "^27.3.1",
"jest": "^27.3.1"
}
My babel.config.js:
module.exports = {
presets: [['#babel/preset-env', {targets: {node: 'current'}}]],
};
My index.js:
import { path } from 'd3-path'
export default () => path()
The test file:
import fn from '../src/index.js'
describe('test', () => {
it('works', () => {
fn()
expect(2 + 2).toBe(4)
})
})
The error message:
({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){export {default as path} from "./path.js";
^^^^^^
SyntaxError: Unexpected token 'export'
> 1 | import { path } from 'd3-path'
To reproduce:
git clone https://github.com/luucvanderzee/jest-problem.git
cd jest-problem
npm i
npm run test
// The test runs without failure- this is because we're currently still using d3-path#2.0.0
npm uninstall d3-path && npm install d3-path // (upgrade to d3-path#3.0.1)
npm run test
// Now the test fails.
How should I configure jest and/or babel to solve this issue?
EDIT:
I already tried the following (from this page of the jest docs):
Creating a jest.config.js file with the following:
module.exports = {
transform: {}
}
Changing my "test" command from "jest" to "node --experimental-vm-modules node_modules/jest/bin/jest.js"
This gives me another error:
/home/luuc/Projects/javascript/jest-problem/test/test.test.js:1
({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){import fn from '../src/index.js'
^^^^^^
SyntaxError: Cannot use import statement outside a module
I also don't get what is meant by
• To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
Isn't the problem that the module is not transformed? Would adding an ignore pattern not just lead to the module not getting transformed?
Problem
The error happens because jest does not send the content of node_modules to be transformed by babel by default.
The following output line of npm run test indicates one way to solve the problem:
• To have some of your "node_modules" files transformed, you can specify a custom "transformIgnorePatterns" in your config.
Solution
The configuration of jest should be updated in order to instruct it to transform the ESM code present in d3-path dependency.
To do so, add the following to a jest.config.js file in the root directory of the project:
module.exports = {
transformIgnorePatterns: ['node_modules/(?!(d3-path)/)']
}
npm run test runs fine after that.
The transformIgnorePatterns option is documented here.
Edit - including more modules
In order to include all modules starting with d3, the following syntax may be used:
transformIgnorePatterns: ['/node_modules/(?!(d3.*)/)']
TLDR;
transformIgnorePatterns: [
"/node_modules/(?!d3|d3-array|d3-axis|d3-brush|d3-chord|d3-color|d3-contour|d3-delaunay|d3-dispatch|d3-drag|d3-dsv|d3-ease|d3-fetch|d3-force|d3-format|d3-geo|d3-hierarchy|d3-interpolate|d3-path|d3-polygon|d3-quadtree|d3-random|d3-scale|d3-scale-chromatic|d3-selection|d3-shape|d3-time|d3-time-format|d3-timer|d3-transition|d3-zoom}|internmap|d3-delaunay|delaunator|robust-predicates)"
]
For the ones reaching this page after updating recharts dependency, here I found the solution, provided by them.
I'm attempting make a few functions using the Test Driven Development (TDD)
I am writing in javascript.
checkTransparency(urlString)
maketransparent(urlString)
are two functions of mine I'm trying to test and develop which is located in a file called transcript.js.
These uses the inkscape and graphicsmagick npm. I checked checkTransparent works in some other project of mine, but I'm trying to make sure I can just copy paste this transparent.js into another project and use it elsewhere as well.
My folder structure of the project are the following :
+ node_modules
+ src
--- transparent.js
+ test
--- transparent.spec.js
+ package.json
+ package-lock.json
+ jest.config.js
I am using jest as my test framework.
The problem is when I run jest (or npm test)
I get the following:
FAIL test/transparent.spec.js
● Test suite failed to run
Jest encountered an unexpected token
This usually means that you are trying to import a file which Jest cannot parse, e.g. it's not plain JavaScript.
By default, if Jest sees a Babel config, it will use that to transform your files, ignoring "node_modules".
Here's what you can do:
• 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/en/configuration.html
Details:
\\..............\transparent\test\transparent.spec.js:4 <FEW DETAILS OMITTED HERE DELIBERATELY>
import { checkTransparency, makeTransparent } from "../src/transparent"; // const transparent = require("../src/transparent");
^^^^^^
SyntaxError: Cannot use import statement outside a module
at Runtime._execModule (C:/Users/Kjeong/AppData/Local/Yarn/Data/global/node_modules/jest-runtime/build/index.js:988:58)
Test Suites: 1 failed, 1 total
Tests: 0 total
Snapshots: 0 total
Time: 0.862s
Ran all test suites.
my jest.config.js:
module.exports = {
testEnvironment: "node",
moduleDirectories: ["node_modules", "src", "transparent"],
moduleFileExtensions: [
"js",
"json",
"jsx",
"ts",
"tsx",
"node"
],
clearMocks: true,
}
I've tried the following exports to get this thing working:
export function checkTransparency(urlString) { ... }
export function makeTransparent(urlString) {... }
module.exports = {
checkTransparency: checkTransparency,
makeTransparent: makeTransparent,
};
In your package.json, using configuration like following could solve your problem:
{
"name": "<blah blah>",
"version": "1.0.0",
"description": "",
"type": "module",
"scripts": {
"start": "node server.js",
"test": "node --experimental-vm-modules node_modules/.bin/jest"
},
}
If you really want to use import keyword then you probably need to follow these explanations. Otherwise why not just require ?
const { checkTransparency, makeTransparent } = require('../src/transparent')
Hope this helps :)
When trying to extend the Request interface from the package express to add some custom properties, I'm getting the following typescript error:
TS2339: Property '' does not exist on type 'Request<ParamsDictionary>'.
Do you know how to solve that?
Since a recent update of its typings and dependencies, I found that the following should fix the errors in your application.
In your tsconfig.json
{
"compilerOptions": {
//...
"typeRoots": [
"./custom_typings",
"./node_modules/#types"
],
}
// ...
}
And in your custom typings
// custom_typings/express/index.d.ts
declare namespace Express {
interface Request {
customProperties: string[];
}
}
Just add the following, what this does is it simply adds a custom property to the express Request interface
declare global {
namespace Express {
interface Request {
propertyName: string; //or can be anythin
}
}
}
I recently had the same issue, I followed the solution in the previous comments and this repo and I still had the same issue. After doing more digging it seems like it's a bug with ts-node.
To solve this you need to run your server with a --files flag
So if you normally run your server
ts-node ./src/server.ts or nodemon ./src/server.ts
Change it to
ts-node --files ./src/server.ts or nodemon --files ./src/server.ts
After that, I was able to get rid of both the VScode errors and errors while starting the server.
In my case it was missing types for express. What I'm currently working on is migrating our codebase from Yarn to PNPM. The difference with PNPM is it doesn't hoist dependencies the way Yarn does so I had to add the dependencies on the package.json for each workspace that would use that dependency.
This is the error I encountered:
TSError: ⨯ Unable to compile TypeScript:
../server/src/api/filters/googleFilter.ts:6:23 - error TS2339: Property 'headers' does not exist on type 'Request<core.ParamsDictionary>'.
6 const idToken = req.headers.authorization;
It took me quite a few searches to look for a fix when I decided to open up the node_modules folder of that workspace. Inside node_modules/#types/express/index.d.ts
/// <reference types="express-serve-static-core" />
/// <reference types="serve-static" />
import * as bodyParser from "body-parser";
import serveStatic = require("serve-static");
import * as core from "express-serve-static-core";
import * as qs from "qs";
I saw my IDE showing errors telling me that it cannot find the types for express-serve-static-core and serve-static so what I did was to add it on the package.json of that workspace and that fixed the errors on the terminal.
Hope this helps someone else who will encounter the same issue with PNPM.
This worked for me!
Using ts-node
Add the following file to add a property to the express Request interface as suggested by #Rishav Sinha
Add this file src/types/types.custom.d.ts
declare global {
declare namespace Express {
interface Request {
user?: any,
page?: number,
}
}
}
// If this file has no import/export statements (i.e. is a script)
// convert it into a module by adding an empty export statement.
export { }
Add in tsconfig.json
{
"compilerOptions": {
//...
"typeRoots": [
"./types",
"./node_modules/#types"
],
}
// ...
}
Run this command with --files options as suggested by #Shahar Sharron
If you installed globally ts-node
$ ts-node --files ./src/index.ts
or to run from your project dependencies ts-node
$ npx ts-node --files ./src/index.ts
Using nodemon
If you want to use nodemom
Add this file in folder project nodemon.json
{
"watch": ["src/**/*.ts"],
"ext": "ts,json",
"ignore": [
"src/**/*.spec.ts",
"src/**/*.test.ts"
],
"exec": "npx ts-node --files ./src/index.ts"
}
Run nodemon
$ nodemon