ava VS Sinon.JS

We use Jest Framework for testing. Jest is not a dogma, and, of course, in its place can be any other test runner, such as Mocha or Ava. Let's focus on tests. I'll provide a short example because I don’t want to waste your time. You can find the full version here. It's crucial to read the comments in the code below. Let's go!

> In the popular jest test runner, each test file is executed in its own child process.

Is that confirmed?

I've been following this issue:

https://github.com/jestjs/jest/issues/6957

And what Jest actually does is still kind of muddy.

In contrast to that, other test runners like AVA have a clear description what happens when:

https://github.com/avajs/ava/blob/main/docs/01-writing-tests...

I've been looking at using japa or ava for web server testing but was curious what others were using and why.

Continued work on the test suite. Implementing AVA, with snapshotting. Making a lot of effort to have the snapshot directory structure match the test262 test directory structure by generating AVA test files.

You might want to give ava a spin:

https://github.com/avajs/ava/

It has a TAP reporter, but more importantly, as opposed to the more popular solutions, like Jest, the way it achieves parallelism is explained in the docs and won't change anytime soon, thus preventing wonky, hard to debug errors which occur when this part is abstracted away.

I switched to ava for that reason and have been very happy with it. But vitest looks nice, too. Thanks for the pointer.

Runs unit tests using AVA.

Last but not least important are ava, uvu and tape; they are a really light and fast test runners.

I've had some good experiences with Ava + Sinon. I've personally disliked Jest because it seemed to do some weird trickery in the background that prevented me from using ES modules.

Ava for a simpler environment than Jest, which I usually use. I need to check how to mock ESM with it, though.

If you are using a mocking library, such as sinon, jest-mock, or ts-mockito, make sure that it is compatible with Jest. You may need to install additional packages or configure them in your configuration file. For example, to use sinon with Jest, you can install the sinon-jest package and add the following to your configuration file:

Mocha is a test runner, Chai is an assertion library, Sinon is a mocking library, this normally the combination you would need to use if you choose mocha, but there are others.

Instead, use pure functions + dependency inject your stubs (e.g. parameter to function). Also note, no need for Sinon or some other test double library. JavaScript is so good nowadays to easily make objects/classes/functions or any combination thereof on the fly that are terse.

I've had some good experiences with Ava + Sinon. I've personally disliked Jest because it seemed to do some weird trickery in the background that prevented me from using ES modules.

🤖 You can use the Mocha testing framework with the Chai assertion library to write tests for your Express controller. You can also use the Sinon library to mock the database calls. This will allow you to test the controller without actually making a call to the database. You can also use the SuperTest library to make HTTP requests to the controller and test the response.

You can use sinon js to create a mock version of your http library (axios) that responds with the data you’re expecting.

Assertions are the checkpoints of our test block that confirm if an automated test has passed or failed. Cypress bundles the Chai, jQuery, and Sinon.JS libraries for assertions. They check the desired, expected application in which the test is running. A complete listing of assertions can be found in the documentation here.

ES module is basically a "class" that you inject dependencies into through imports. And for tests you just use something like sinon to swap module dependencies for mocks.

You can use a tool like sinon to pass in your own function instead of the real moment library. From there you can write tests that ensure moment was invoked appropriately.

Let's configure tests with mocha, chai and sinon on Typescript in a few steps.