jest | Delightful JavaScript Testing | Testing library

 by   facebook TypeScript Version: 29.6.2 License: MIT

kandi X-RAY | jest Summary

kandi X-RAY | jest Summary

jest is a TypeScript library typically used in Testing, Jest applications. jest has no bugs, it has no vulnerabilities, it has a Permissive License and it has medium support. You can download it from GitHub.

Delightful JavaScript Testing.

            kandi-support Support

              jest has a medium active ecosystem.
              It has 41820 star(s) with 6333 fork(s). There are 566 watchers for this library.
              There were 3 major release(s) in the last 12 months.
              There are 449 open issues and 6868 have been closed. On average issues are closed in 251 days. There are 95 open pull requests and 0 closed requests.
              It has a neutral sentiment in the developer community.
              The latest version of jest is 29.6.2

            kandi-Quality Quality

              jest has 0 bugs and 0 code smells.

            kandi-Security Security

              jest has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.
              jest code analysis shows 0 unresolved vulnerabilities.
              There are 0 security hotspots that need review.

            kandi-License License

              jest is licensed under the MIT License. This license is Permissive.
              Permissive licenses have the least restrictions, and you can use them in most projects.

            kandi-Reuse Reuse

              jest releases are available to install and integrate.
              Installation instructions, examples and code snippets are available.
              It has 958 lines of code, 0 functions and 1595 files.
              It has low code complexity. Code complexity directly impacts maintainability of the code.

            Top functions reviewed by kandi - BETA

            kandi's functional review helps you automatically verify the functionalities of the libraries and avoid rework.
            Currently covering the most popular Java, JavaScript and Python libraries. See a Sample of jest
            Get all kandi verified functions for this library.

            jest Key Features

            No Key Features are available at this moment for jest.

            jest Examples and Code Snippets

            JavaScriptdot img1Lines of Code : 280dot img1no licencesLicense : No License
            copy iconCopy
            var board = '090000006\n' + 
                        '000960485\n' +
                        '000581000\n' +
                        '004000000\n' +
                        '517200900\n' +
                        '602000370\n' +
                        '100804020\n' +
                        '706000810\n' +
            TypeScriptdot img2Lines of Code : 105dot img2no licencesLicense : No License
            copy iconCopy
            import initStore from "lemon-state";
            const initialState = {
              loading: true,
              lang: "ru",
              data: []
            const actions = {
              onSetLoad: ({ state }, payload) => ({
                loading: payload
              onSwitchLang: ({ state }, payload) => ({
            React Native Animated Screen,Usage,AnimatedScreen.Header
            TypeScriptdot img3Lines of Code : 48dot img3License : Permissive (MIT)
            copy iconCopy
              animatedStyle={ scrollY => ({
               opacity: scrollY.interpolate({
                 inputRange: [0, 200], // from 0 scrolled to headerMaxHeight scrolled
                 outputRange: [1, 0]
              // Expects a callback returning the component to  
            jest - Intro
            JavaScriptdot img4Lines of Code : 32dot img4License : Permissive (MIT License)
            copy iconCopy
            // Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
             * Sample React Native App
            import React, {Component} from 'react';
            import {StyleSheet, Text, View} from 'react-native';
            const st  
            jest - mock per test
            JavaScriptdot img5Lines of Code : 26dot img5License : Permissive (MIT License)
            copy iconCopy
            // Copyright 2004-present Facebook. All Rights Reserved.
             * This file illustrates how to define a custom mock per test.
             * The file contains two test cases:
             * - One where the fruit module is mocked.
             * - One where the fruit module is not moc  
            jest - Link
            JavaScriptdot img6Lines of Code : 24dot img6License : Permissive (MIT License)
            copy iconCopy
            // Copyright 2004-present Facebook. All Rights Reserved.
            import {useState} from 'react';
            const STATUS = {
              HOVERED: 'hovered',
              NORMAL: 'normal',
            export default function Link({page, children}) {
              const [status, setStatus] = useState(STATUS.N  
            Why does expect-tcl use the semicolon to trim the output?
            JavaScriptdot img7Lines of Code : 4dot img7License : Strong Copyleft (CC BY-SA 4.0)
            copy iconCopy
            expect ">" {
            expect "\n\s*>" {
            Aborts during checkouts
            JavaScriptdot img8Lines of Code : 105dot img8License : Strong Copyleft (CC BY-SA 4.0)
            copy iconCopy
            #! /bin/sh -e
            mkdir gitcommits
            cd gitcommits
            echo a > filea.txt
            echo b > fileb.txt
            git init
            git add .
            git commit -q -m Commit0
            echo 'a*' > filea.txt
            git stash
            echo 'b*' > fileb.txt
            git add fileb.txt
            git commit -q -m Commit1
            Angular: window.print() unit test
            Lines of Code : 13dot img9License : Strong Copyleft (CC BY-SA 4.0)
            copy iconCopy
            it('should call print and cancel', () => {
              // spy on print and cancel on window object
              const printSpy = spyOn(window, 'print');
              const cancelSpy = spyOn(window, 'cancel');
              // call print
              component.print({/* mock component howev
            Add key to array of objects in async function
            JavaScriptdot img10Lines of Code : 37dot img10License : Strong Copyleft (CC BY-SA 4.0)
            copy iconCopy
            // since we decorated "async" let's use await...
            export default async function getProduct(product_id) {
              const url = `${process.env.PRIVATE_APP_URL}/products/${product_id}.json`;
              const options = { method: "GET", headers: { "Content-Type

            Community Discussions


            Error while loading rule 'prettier/prettier': context.getPhysicalFilename is not a function
            Asked 2022-Apr-04 at 13:24

            I am learning react js. I am a very beginner at this topic. But when I am doing setup to create a react environment I got an error. I have tried to solve the problem by Charles Stover blog in medium. But I got an error Command "up" not found.

            Here's my index.js file:



            Answered 2021-Sep-06 at 09:40

            I got two different solution.

            1. remove



            Invalid options object. Dev Server has been initialized using an options object that does not match the API schema
            Asked 2022-Mar-28 at 21:08

            I have been stock on this error on my project when I add "proxy": "http://localhost:6000" in my package.json.

            This is the error response after yarn start.

            Invalid options object. Dev Server has been initialized using an options object that does not match the API schema.

            • options.allowedHosts[0] should be a non-empty string. error Command failed with exit code 1. info Visit for documentation about this command.

            But everything is fine when I remove the "proxy": "http://localhost:6000".

            This is on my package.json:



            Answered 2021-Dec-19 at 16:06

            Here is a workaround. Delete "proxy": "http://localhost:6000". Install package http-proxy-middleware with command npm install http-proxy-middleware --save. Create a file setupProxy.js inside your src folder. Add these lines inside:



            The unauthenticated git protocol on port 9418 is no longer supported
            Asked 2022-Mar-27 at 13:23

            I have been using github actions for quite sometime but today my deployments started failing. Below is the error from github action logs



            Answered 2022-Mar-16 at 07:01

            First, this error message is indeed expected on Jan. 11th, 2022.
            See "Improving Git protocol security on GitHub".

            January 11, 2022 Final brownout.

            This is the full brownout period where we’ll temporarily stop accepting the deprecated key and signature types, ciphers, and MACs, and the unencrypted Git protocol.
            This will help clients discover any lingering use of older keys or old URLs.

            Second, check your package.json dependencies for any git:// URL, as in this example, fixed in this PR.

            As noted by Jörg W Mittag:

            There was a 4-month warning.
            The entire Internet has been moving away from unauthenticated, unencrypted protocols for a decade, it's not like this is a huge surprise.

            Personally, I consider it less an "issue" and more "detecting unmaintained dependencies".

            Plus, this is still only the brownout period, so the protocol will only be disabled for a short period of time, allowing developers to discover the problem.

            The permanent shutdown is not until March 15th.

            For GitHub Actions:

            As in actions/checkout issue 14, you can add as a first step:



            Consider using the "jsdom" test environment
            Asked 2022-Mar-23 at 20:23

            I have this simple test:



            Answered 2021-Oct-25 at 05:17

            In your package.json, or jest.config.js/jest.config.js, change the value of the testEnvironment property to jsdom.




            Making a JSX syntax for a MockComponent and have it typed with typescript
            Asked 2022-Mar-20 at 22:37

            Wondering if anybody has some good suggestions on how to crack this. Got this test helper utils I have added some types to:



            Answered 2022-Mar-20 at 22:37

            If you look at React without JSX, you'll see that the XML-inspired syntax () is just short for React.createElement('MockComponent').

            Right now, if you renamed mockComponent to MockComponent and tried using the angle bracket syntax, the first issue is that your function receives two arguments. React components are either class components that take one constructor argument (props) or functional components that take one argument (again, props). The second issue is that your function returns a React functional component, when it needs to return a rendered React element.

            One way to fix this issue is to convert mockComponent into a React functional component and make module and propOverride props of the FC.



            ESlint - Error: Must use import to load ES Module
            Asked 2022-Mar-17 at 12:13

            I am currently setting up a boilerplate with React, Typescript, styled components, webpack etc. and I am getting an error when trying to run eslint:

            Error: Must use import to load ES Module

            Here is a more verbose version of the error:



            Answered 2022-Mar-15 at 16:08

            I think the problem is that you are trying to use the deprecated babel-eslint parser, last updated a year ago, which looks like it doesn't support ES6 modules. Updating to the latest parser seems to work, at least for simple linting.

            So, do this:

            • In package.json, update the line "babel-eslint": "^10.0.2", to "@babel/eslint-parser": "^7.5.4",. This works with the code above but it may be better to use the latest version, which at the time of writing is 7.16.3.
            • Run npm i from a terminal/command prompt in the folder
            • In .eslintrc, update the parser line "parser": "babel-eslint", to "parser": "@babel/eslint-parser",
            • In .eslintrc, add "requireConfigFile": false, to the parserOptions section (underneath "ecmaVersion": 8,) (I needed this or babel was looking for config files I don't have)
            • Run the command to lint a file

            Then, for me with just your two configuration files, the error goes away and I get appropriate linting errors.



            Switch' is not exported from 'react-router-dom'
            Asked 2022-Mar-01 at 09:07

            In package.json file react-router-dom dependencies added. App component wrapped by BrowswerRouter , but when I wrap route by switch it says the following error Switch' is not exported from 'react-router-dom'. I deleted the package.json.lock ,node modules, installed npm again and npm install @babel/core --save. Still not working. I successfully wasted 6 hour for this. Can you please help me to fix this? why it's not importing?




            Answered 2021-Nov-04 at 18:10
            Using Routes instead of Switch in react-router v6

            You are using react-router-dom version 6, which replaced Switch with the Routes component



            "Cannot read properties of undefined (reading 'pathname')" when testing pages in the v6 React Router
            Asked 2022-Feb-03 at 00:48

            When testing components with s, for example in my answer to Recommended approach for route-based tests within routes of react-router, I often use the following pattern to get access to the current location for testing purposes:



            Answered 2021-Nov-06 at 10:28

            React Router v6 splits apart the history into multiple pieces, for this use case the relevant parts are the navigator and the location. This change is hinted at in Use useNavigate instead of useHistory, and you can see it in the definition of the Navigator type used in the Router props:



            eslint / typescript: Unable to resolve path to module
            Asked 2022-Feb-02 at 23:32

            My .eslintrc.json is:



            Answered 2022-Jan-11 at 17:06

            It looks like you have defined custom paths in your TypeScript config (usually tsconfig.json). The import plugin doesn't know about the correct location of the TypeScript config and hence cannot resolve those paths. What you need to do, is to specify the correct path to your TypeScript config via the project parameter in the resolver options:



            Vue 3: Module '"../../node_modules/vue/dist/vue"' has no exported member
            Asked 2022-Jan-24 at 08:38

            After updating my npm packages, some of the imports from the 'vue' module started showing errors:

            TS2305: Module '"../../node_modules/vue/dist/vue"' has no exported member 'X'

            where X is nextTick, onMounted, ref, watch etc. When serving the project, Vue says it's "failed to compile". WebStorm actually recognizes the exports, suggests them and shows types, but the error is shown regardless. Some exports like computed and defineComponent work just fine.

            What I've tried:

            • Rollback to the previously used Vue version "3.2.2" > "3.0.11". It makes the abovementioned type errors disappear, but the app stops working entirely, showing lots of TypeError: Object(...) is not a function errors in console and not rendering the app at all. In the terminal, some new warnings are introduced: "export 'X' (imported as '_X') was not found in 'vue' where X is createElementBlock, createElementVNode, normalizeClass and normalizeStyle.
            • Rollback other dependencies. None of the ones that I tried helped fix the problem, unfortunately.
            • Manually declare the entirety of 'vue' module. We can declare the 'vue' module exports in shims-vue.d.ts, and it actually makes the errors disappear, however, this seems like a terrible, time-consuming workaround, so I would opt out for a better solution if possible.

            My full list of dependencies:



            Answered 2021-Aug-15 at 13:53

            That named exports from composition API are unavailable means that vue is Vue 2 at some place which has only default export. Since Vue 3 is in dependencies and both lock file and node_modules were refreshed, this means that Vue 2 is nested dependency of some direct dependency.

            The problem needs to be investigated in lock file. It shows that @vue/cli-plugin-unit-jest@4.5.13 depends on vue-jest@3 which depends on vue@2.

            A possible solution is to upgrade @vue/cli-plugin-unit-jest to the latest version, next. The same likely applies to other @vue/cli-* packages because they have matching versions.


            Community Discussions, Code Snippets contain sources that include Stack Exchange Network


            No vulnerabilities reported

            Install jest

            Install Jest using yarn:.


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