TS & Jest mocks

[embiem]

Nice Blog!

I recently came across your blog as it was top google search result for jest mockimplementation typescript. Specifically this page: https://klzns.github.io/how-to-use-type-script-and-jest-mocks

This didn't work for me in current TS version, but this did work: kulshekhar/ts-jest#576 (comment)

Maybe you'd consider updating the post as it is first result in Google searches?

Cheers!

[klzns]

Hi @embiem, thanks for the feedback!

I've tested the solution proposed in my blog post and it seemed to work fine.

I tested in two ways:

Using create-react-app with TS

I created a fresh install of create-react-app with TS running:

1. yarn create react-app my-app --template typescript
2. yarn add @testing-library/react @testing-library/jest-dom

And I created two examples:

1. Example mocking a node module
2. Example mocking a local module

That's the output of the tests:

In this test I used TypeScript v3.7.5.

Using react-boilerplate-typescript

Since the first test worked fine, I thought the issue might be related to the usage of ts-jest.

So I also created a branch using the react-boilerplate-typescript that someone mentioned in the thread.

With the same two examples:

1. Example mocking a node module
2. Example mocking a local module

And got the same results:

Things to check

Make sure you have @types/jest in your project devDependencies or dependencies.

Let me know if you find what I'm missing here! Thanks

[embiem]

You're right, it does work. I'm honestly not 100% sure why it didn't work back when I posted this issue.

I remember that I tried your approach, which didn't work at the time, then came across the solution using ts-jest/utils (kulshekhar/ts-jest#576 (comment)), which worked perfectly.

Thanks for taking the time to double-check this!