Skip to main content
22,936 questions
Newest Active Bountied Unanswered
Filter by
Sorted by
Tagged with
924 votes
28 answers
953k views

I have a test 'works with nested children' within the file fix-order-test.js. Running the below runs all the tests in the file. jest fix-order-test How do I run only a single test? The below does ...
vijayst's user avatar
  • 22.1k
908 votes
34 answers
1.3m views

I am able to test multiple files using Jest, but I cannot figure out how to test a single file. I have: Run npm install jest-cli --save-dev Updated package.json: `{ ... "scripts": { "...
Musket's user avatar
  • 9,495
751 votes
8 answers
274k views

I have two tests in my test group. One of the tests use it and the other one uses test. Both of them seem to be working very similarly. What is the difference between them? describe('updateAll', () =&...
C.Lee's user avatar
  • 11.4k
592 votes
23 answers
821k views

I'm working with some code where I need to test the type of an exception thrown by a function (is it TypeError, ReferenceError, etc.?). My current testing framework is AVA and I can test it as a ...
bartsmykla's user avatar
  • 6,091
506 votes
29 answers
548k views

I'm using Puppeteer and Jest to run some front end tests. My tests look as follows: describe("Profile Tab Exists and Clickable: /settings/user", () => { test(`Assert that you can ...
Asool's user avatar
  • 14.3k
503 votes
11 answers
520k views

I want to test that one of my ES6 modules calls another ES6 module in a particular way. With Jasmine this is super easy -- The application code: // myModule.js import dependency from './dependency'; ...
Cam Jackson's user avatar
  • 12.4k
491 votes
10 answers
202k views

I'm writing an async test that expects the async function to throw like this: it("expects to have failed", async () => { let getBadResults = async () => { await failingAsyncTest() } ...
Sean's user avatar
  • 5,194
488 votes
14 answers
434k views

I have a component library that I'm writing unit tests for using Jest and react-testing-library. Based on certain props or events I want to verify that certain elements aren't being rendered. ...
SomethingOn's user avatar
  • 11.1k
434 votes
33 answers
494k views

I have a React application (not using Create React App) built using TypeScript, Jest, Webpack, and Babel. When trying to run yarn jest, I get the following error: I have tried removing all packages ...
Logan Shoemaker's user avatar
  • 4,677
386 votes
32 answers
399k views

I'm using moment.js to do most of my date logic in a helper file for my React components but I haven't been able to figure out how to mock a date in Jest a la sinon.useFakeTimers(). The Jest docs only ...
alengel's user avatar
  • 5,078
380 votes
24 answers
487k views

console.log statements output nothing at all in Jest. This was working for me yesterday, and all of sudden, it's not working today. I have made zero changes to my config and haven't installed any ...
Hina Dawood's user avatar
  • 3,921
379 votes
14 answers
213k views

I'm attempting to use the ESLint linter with the Jest testing framework. Jest tests run with some globals like jest, which I'll need to tell the linter about; but the tricky thing is the directory ...
Retsam's user avatar
  • 33.8k
347 votes
17 answers
451k views

I have an application that depends on environmental variables like: const APP_PORT = process.env.APP_PORT || 8080; And I would like to test that for example: APP_PORT can be set by a Node.js ...
Tomasz Mularczyk's user avatar
  • 36.4k
346 votes
11 answers
661k views

Is there a way to have code coverage in the JavaScript Jest testing framework, which is built on top of Jasmine? The internal framework does not print out the code coverage it gets. I've also tried ...
Alex Palcuie's user avatar
  • 5,054
315 votes
13 answers
239k views

I'm running Jest tests via npm test. Jest runs tests in parallel by default. Is there any way to make the tests run sequentially? I have some tests calling third-party code which relies on changing ...
Martin Konicek's user avatar
  • 41.1k
299 votes
5 answers
323k views

Jest is picking up an old version of a package and thus my tests fail unless I use --no-cache. I can even delete the package folder from folder node_modules and Jest is happy to run the tests (almost ...
Manuel's user avatar
  • 11.6k
291 votes
6 answers
330k views

I have a mapModule where I import components and export them: import ComponentName from '../components/ComponentName'; export default { name: ComponentName, }; How can I test that mapModule has ...
fasenberg's user avatar
  • 3,125
289 votes
15 answers
214k views

I wonder if there is a better way to disable console errors inside a specific Jest test (i.e. restore the original console before/after each test). Here is my current approach: describe("Some ...
Apidcloud's user avatar
  • 4,068
273 votes
6 answers
315k views

I'm trying to use it for testing if a function was called or not. I noticed the mock.calls.length is not resetting for every test but accumulating. How can I make it 0 before every test? I don't want ...
Alex Efremov's user avatar
  • 7,294
266 votes
31 answers
251k views

I keep getting "localStorage is not defined" in Jest tests which makes sense but what are my options? Hitting brick walls.
Chiedo's user avatar
  • 7,584
263 votes
8 answers
227k views

I'd like to change the implementation of a mocked dependency on a per single test basis by extending the default mock's behaviour and reverting it back to the original implementation when the next ...
Andrea Carraro's user avatar
  • 10.6k
259 votes
21 answers
290k views

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 ...
Don P's user avatar
  • 64.3k
256 votes
17 answers
395k views

I need to test a function which opens a new tab in the browser openStatementsReport(contactIds) { window.open(`a_url_${contactIds}`); } I would like to mock window's open function, so I can verify ...
danny's user avatar
  • 3,336
254 votes
19 answers
299k views

Here is my code for a tooltip that toggles the CSS property display: block on MouseOver and on Mouse Out display: none. it('should show and hide the message using onMouseOver and onMouseOut events ...
dorriz's user avatar
  • 2,769
254 votes
6 answers
191k views

I have an analytics tracker that will only call after 1 second and with an object where the intervalInMilliseconds (duration) value is not deterministic. How can I use jest.toHaveBeenCalledWith to ...
dotnetCarpenter's user avatar
  • 11.4k
252 votes
7 answers
183k views

I only want to mock a single function (named export) from a module but leave the rest of the module functions intact. Using jest.mock('package-name') makes all exported functions mocks, which I don't ...
spencer.sm's user avatar
  • 20.8k
251 votes
7 answers
222k views

How can I get the arguments called in jest mock function? I want to inspect the object that is passed as argument.
Bruno Quaresma's user avatar
  • 10.8k
248 votes
38 answers
246k views

When using TypeScript in conjunction with Jest, my specs would fail with error messages like: test/unit/some.spec.ts:1:1 - error TS2582: Cannot find name 'describe'. Do you need to install type ...
Ronin's user avatar
  • 8,096
233 votes
24 answers
180k views

This is my first front-end testing experience. In this project, I'm using Jest snapshot testing and got an error TypeError: window.matchMedia is not a function inside my component. I go through Jest ...
TIJ's user avatar
  • 3,271
232 votes
6 answers
207k views

I'm using Jest framework and have a test suite. I want to turn off/skip one of my tests. Googling documentation doesn't give me answers. Do you know the answer or source of information to check?
Gleichmut's user avatar
  • 7,109
232 votes
15 answers
240k views

When testing a module that has a dependency in a different file and assigning that module to be a jest.mock, TypeScript gives an error that the method mockReturnThisOnce (or any other jest.mock method)...
Philip Chmalts's user avatar
  • 2,498
231 votes
12 answers
225k views

I am using react jest with react testing library to test my component. I am facing a weird issue. I am using debug, returned by render from testing-library. test('component should work', async () =>...
Amit Chauhan's user avatar
  • 7,019
226 votes
5 answers
179k views

When writing a unit test in Jest or Jasmine when do you use describe? When do you use it? I usually do describe('my beverage', () => { test('is delicious', () => { }); }); When is it time ...
Brown Limie's user avatar
  • 2,629
225 votes
11 answers
192k views

I get that .toEqual() checks equality of all fields for plain objects: expect( {"key1":"pink wool","key2":"diorite"} ).toEqual( {"key2":"...
Benjamin H Boruff's user avatar
  • 3,029
224 votes
4 answers
328k views

I'm testing my GraphQL api using Jest. I'm using a separate test suit for each query/mutation I have 2 tests (each one in a separate test suit) where I mock one function (namely, Meteor's callMethod)...
Le garcon's user avatar
  • 8,677
221 votes
11 answers
269k views

Let's suppose I have the following class: export default class Person { constructor(first, last) { this.first = first; this.last = last; } sayMyName() { console....
CrazySynthax's user avatar
  • 15.2k
209 votes
12 answers
219k views

I've having a strange problem with this test: deal.test.js import Deal from "../src/models/Deal"; import apiProducts from "../__mocks__/api/products"; describe("Deal", ()...
Jonathan Tuzman's user avatar
  • 13.6k
209 votes
8 answers
245k views

I have the following module I'm trying to test in Jest: // myModule.js export function otherFn() { console.log('do something'); } export function testFn() { otherFn(); // do other things } ...
Jon Rubins's user avatar
  • 4,433
207 votes
13 answers
172k views

If I use import/export from ES6 then all my Jest tests fail with error: Unexpected reserved word I convert my object under test to use old school IIFE syntax and suddenly my tests pass. Or, take an ...
P.Brian.Mackey's user avatar
  • 44.4k
206 votes
16 answers
361k views

Receiving the following error when running Jest Cannot find module 'src/views/app' from 'index.jsx' at Resolver.resolveModule (node_modules/jest-resolve/build/index.js:179:17) at Object.<...
Seth McClaine's user avatar
  • 10.1k
203 votes
6 answers
200k views

I have a spy that is used in multiple assertions across multiple tests in a suite. How do I clear or reset the spy so that in each test the method that the spy intercepts is considered not to have ...
sdgluck's user avatar
  • 27.8k
203 votes
20 answers
293k views

I couldn't get rid of this SyntaxError: Cannot use import statement outside a module error no matter what I have tried and it got so frustrating. Is there anybody out here solved this issue? I have ...
dugong's user avatar
  • 4,621
202 votes
32 answers
238k views

I'm trying to write tests for my simple React App that creates a UI for a dog Shelter using API etc. I have imported the modules shown below and ran the following command npm install jest-dom react-...
mangokitty's user avatar
  • 2,529
202 votes
22 answers
282k views

Currently, I am implementing unit tests for my project and there is a file that contains window.location.href. I want to mock this to test and here is my sample code: it("method A should work ...
Hoang Subin's user avatar
  • 7,560
200 votes
24 answers
160k views

I am setting a configuration to run my tests in a create-react-app + typescript app (from which I have ejected). I am using jest + enzyme. In my tsconfig.json I have set baseUrl='./src' so I can use ...
TheSoul's user avatar
  • 5,396
194 votes
10 answers
480k views

I am totally new to JavaScript testing and am working in a new codebase. I would like to write a test that is checking for a className on the element. I am working with Jest and React Testing Library. ...
Giesburts's user avatar
  • 7,846
193 votes
8 answers
233k views

I want to run just one test with Jest. I use it.only or describe.only, but it still runs a whole lot of tests. I think it runs all the tests since my last commit, but it shouldn't have this behavior ...
jpenna's user avatar
  • 9,299
193 votes
15 answers
97k views

Image following test case: it('valid emails checks', () => { ['[email protected]', '[email protected]'/*, ...*/].map(mail => { expect(isValid(mail)).toBe(true); }); }); I would like to add auto-generated ...
Jurosh's user avatar
  • 7,885
191 votes
6 answers
164k views

Jest documentation reads: toBe just checks that a value is what you expect. It uses === to check strict equality. And for toEqual: Use .toEqual when you want to check that two objects have the ...
sshh's user avatar
  • 7,252
183 votes
13 answers
254k views

I'm doing some slightly bizarre stuff using Jest for testing where I'm writing some stuff to disk. If I use the watch flag in Jest however then I'm finding (quite obviously) that each time I write ...
Ian's user avatar
  • 34.7k

1
2 3 4 5
…
459