I am learning React, and got stuck in testing one of my components. I use react-use-cart to manage the cart, this is how code looks The test breaks at “productInCart = getItem(product.id)” saying ” TypeError: getItem is not a function”. I’ve been stuck at this for several days, a…
Tag: jestjs
Why jest is not working with imported test data?
Here a test data defined in sum-test-cases.js with the following Here is the jest test file sum.test.js with the following The test failed with the following error: However, instead of importing the data from another file, if I define the data within the test file like the following, the test works as expecte…
Jest skipping S3 Get Object call in function
Im testing a standard S3 Get Object Call, but when Jest tests my function, it skips the Get Object call and jumps to end of function, ending the execution and returning nothing. When I checked code coverage, all lines are covered expect the getObject call. This is my s3 file being tested. I have checkpoints t…
Check if type of emitted variable matches custom type
I am testing some Vue 3 components with jest and expect to get an emit when a button is clicked. Now I want to check if the object emitted matches a custom type I created in a different file. e.g.: My test case looks something like this: But here I get the error Element is not accessible at customType even
Jest redux saga API call with response image
I’m trying to test a fetch that responds with a readable stream for an image, but I’m stuck and not sure how to approach this specific case. Is there a simple, easy way to mock the call’s response? Any help would be appreciated 😀 The generator function looks like the following: Answer You ca…
How to call multi variable array in JS function?
I’m using this function to select one item in drop down menu: Now I want to select multi item before “await this.select();” this step. I tried to edit function like this: but when I call this function to select multi item it has error Expected 0-1 arguments, but got 3 How do I fix this? Answer You can m…
How to mock instance methods of a class mocked with jest.mock?
How can the instance methods be mocked for a class that is being mocked with jest.mock? For example, a class Logger is mocked: Answer Automatic Mocking Calling jest.mock automatically mocks all the exports from the module being mocked unless a manual mock is specified using the __mocks__ directory. So, this l…
How to mock a constructor instantiated class instance using jest?
Given a class Person that instantiates & uses another class Logger, how can the Logger’s method be verified to be called when Person is instantiated in the example below? One option is to pass Logger as a constructor argument like below: However, is there any other way without changing the construct…
how to spy on window.location functions?
i need to cover my code with some unit tests and in one of then i have the following situation. app.tsx and in my test file i’m getting the followein error : Cannot assign to read only property ‘replace’ of object ‘[object Location]’ i’ve tried other aproachs like }); but i…
Debugging jest mocks
I’ve got a library that’s giving me some trouble in my jest tests. This library is included throughout my project, and it has an annoyingFunction that has a console.error in it. So, whenever I run a test, I naturally get unwanted console.error messages all over the place. I don’t want to moc…