When testing a function that uses either the TextEncoder or the TextDecoder I get: I am using jsdom, so why is this not working? Answer While it should be bundled with jsdom, it isn’t with jsdom 16. Therefore you can polyfill like so:
Tag: jestjs
React Testing Library does not find elements using getAllByTestId after initial render
I have a very simple component where I am trying to simulate an API call to get some movies with a slight delay. I want to write a test which tests that the movies are gathered and then rendered to screen. I am trying to use screen.getAllByTestId to do this, however it always fails. It is as if it doesn’…
Jest: ReferenceError: global is not defined
So I am writing unit test using “react-testing-library” on Jest and I have this error: Answer After I added “jest-environment-jsdom”: “^27.0.6” as a dev dependency, that error went away.
jest enzyme TypeError: Cannot read property ‘fn’ of undefined
I am writing test and below is my test case. When I run test I get below error. What is wrong with that and how can I fix this? Answer From the doc: The jest object is automatically in scope within every test file. The methods in the jest object help create mocks and let you control Jest’s overall behav…
How to mock nanoid for testing?
I’m trying to mock nanoid for my testing but it doesn’t seem to be working. my function My test: So basically I’m struggling to figure out how to mock the nanoid which is generated inside the function. I’ve tried the following at the top of the file: however it doesn’t work at al…
Using jest with files with glob imports
I utilize webpack with webpack-import-glob-loader to import files using glob pattern. So in one of my files (src/store/resources/module.ts) I have a line: When I run a test with ts-jest it fails and reports the following message: Cannot find module ‘../../modules/resources/providers/**/*.resource.tsR…
How do I access localStorage or mock localStorage for Jest + vue-test-utils tests?
I am trying to test an axios request, and I need to use an auth token in order to access the endpoint, however my test fails because I am getting “Bearer null” and inputting this into my headers.Authorization. Here is my actual code below File I’m testing: Test file: How do I mock or get the…
Jest with vanilla JS – tesing generated elements on DOM
Searched a lot online but cant find the best way to get an element’s innerHTML and just compare it with the results that should be rendered (I’m trying to compare with string) what I’m trying is adding some whitespace and test failed so I’m guessing there is better ways Also, unable to…
Jest: test that an array contains none of these values?
I want to verify that a given array doesn’t contain any of a list of values. There is expect.arrayContaining but I don’t get how it is supposed to be used for this. See this example: This test fails which is the expected behavior. I want to verify that “3” is not included in the array.…
React testing mock variable in functional component
Please help. I cannot run test because in my util langProvider is package that drops tests. I have to mock langProvider function or strings variable. How I can do that? My test file Answer not sure, but you can try to insert in your test file before describe function, something like that: