I am running tests with jest and enzyme in my React application, and while my simple sanity check test (2+2 expect 4) works, this error is thrown when I go to shallow render a component. It also throws when I try to replace shallow() with render() Here is the app.test.js file: babel.config.js: EDIT : I added babel-jest and now this
Tag: jestjs
What is the proper way to test Vue3 async setup component with suspense?
No doubt that Suspense feature leads to a cleaner code base, but as tidy as it is, it turns to be hard to test. Specifically it is not well documented yet. case: Regular app generated by VUE CLI Tech stack: Vuex, Router, PWA, jest for unit testing Challenge: I made use of Suspense component as recommended as follows: I have
jest ReferenceError: Cannot access ” before initialization
I’m getting the error: ReferenceError: Cannot access ‘myMock’ before initialization Even though i respected jest documentation about the hoisting: A limitation with the factory parameter is that, since calls to jest.mock() are hoisted to the top of the file, it’s not possible to first define a variable and then use it in the factory. An exception is made for variables
Testing Cross Browser Extension With Jest, How To Mock Chrome Storage API?
After putting off testing for a while now due to Cypress not allowing visiting chrome:// urls, I decided to finally understand how to unit/integration test my extension – TabMerger. This comes after the many times that I had to manually test the ever growing functionality and in some cases forgot to check a thing or two. Having automated testing will
JEST | Assert a function was called inside addEventListener callback
I have the following function: Code to test The question is: How can I assert using Jest that createAndAppendPTag was called upon a document click event ? Jest This is what I tried, but can’t seem to make the test pass: Terminal This results in the following: Thanks in advance. Answer I ran this simplified test to check for the
Jest: How to undo a global mock for certain tests in a file
I want to mock Math.random for certain tests and use its original implementation for other tests. How can I achieve this? I’ve read about using jest.doMock and jest.dontMock, but I’ve bumped into a number of issues using them, like: I seem to need require in order to use doMock and dontMock, but my project only uses ES6 modules for importing
Unit test with react hook fails
I don’t understand the result I get on this unit test. I expect the second check for textField.valid to be true and instead it returns false. Below is part of the component I’m testing against: … Below is the test I’m running: The output of console.log(wrapper.debug()) is the following: So why does the test fail? Answer The problem was that
Jest: TypeError: replaceAll is not a function
String.prototype.replaceAll() is a useful method and while building and executing everything works fine. However, all Jest-tests fail with the following error: These are my dependencies: How can I fix this behavior? Answer The problem This happens because replaceAll is a new function not implemented in all browsers nor older Node.js versions (older than 15.0), as mentioned in the other answer.
Mocking dayjs extend
In my code that needs testing I use In my test I need to mock dayjs in order to always have the same date when comparing snapshots in jest so I did It fails with Unfortunately similar questions on here didn’t help me. How could I mock both default dayjs but also extend? Answer You could write a more thorough
Trouble finding Jest on Windows
I recently started off with some project over JavaScript, following some documentation. I am supposed to be using Jest for testing purposes. The installation of Jest seems pretty straightforward on Linux using npm: However, I am on Windows, and unable to find Jest over lets using NuGet. How can I retrieve Jest package over Windows? Answer NPM is bundled with