chai VS uvu

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

These options totally depend on your requirements. For example an empty hardhat option is a very basic project sample if you need more libraries, plugins or you use Typescript later, you have to add them manually. Like @nomiclabs/hardhat-waffle , [ethereum-waffle](https://www.npmjs.com/package/ethereum-waffle), chai , @nomiclabs/hardhat-ethers , ethers , [@openzeppelin/contracts](https://www.npmjs.com/package/@openzeppelin/contracts) Because, they'll allow us to interact with Ethereum and to test our contracts.

For those of you wondering what a "Chaijs" is like I was: https://github.com/chaijs/chai

> BDD / TDD assertion framework for node.js and the browser that can be paired with any testing framework.

ES6 test setup with Mocha and Chai.

It'd be hard for me to imagine what would it be like back then to write tests if it wasn't for Enzyme. Even with Enzyme, it was noticeably harder than it is today, and I still vividly remember installing and configuring in my project Mocha, Chai, Sinon, and JSDOM, to get pretty much the same tooling that today a single library - Jest - provides out of the box, while adding numerous features on top of that.

The library offers a BDD testing style and fully exploits javascript promises - the resulting tests are simple, clear and expressive. Chakram is built on node.js, mocha, chai and request.

For this example, I am using Mocha, plus Chai for its BDD expect syntax and the chai-as-promised plugin for asynchronous matchers.

chai

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

Vitest: A Vite-native unit test framework. (alternative: Jest, uvu)

Most important here is not to forget to include test.run() at the end… I’ve done that a few times 😅. Notice how we are able to use aliases in lines 1–3. You can see the full range of assert methods available in the uvu docs.

For the past few weeks I’ve taken the (arguably pointless) work of migrating Felte from using Jest to uvu. This is a really tedious work by itself, but one of details that would have made this work even more tedious is that Jest prefers assertions to the style of expect(…).toBe* while uvu gives you freedom to choose any assertion library, although there’s an official uvu/assert module that comes with assertions to the style of assert.is(value, expected).

Hello everyone, I'm using uvu for testing. And installed c8 for coverage. Yet it doesn't seem to be able to pick up test .svelte files. Does anyone knows how to achieve this or any other way of getting .svelte files coverage? Thanks

Yes! There’s even an example test written for the svelte counter demo in the repo’s examples!

uvu is what I’d recommend.

I really enjoy Ava [1] or anything assert-tape-like [2]. "uvu" [3] is getting a lot of love lately, but it's very feature limited and much of it's touted advantages are at the detriment to feature set.

[1] https://github.com/avajs/ava

[2] https://github.com/substack/tape

[3] https://github.com/lukeed/uvu

Jest is great for front-end (or full stack integration) testing, but I feel it's specialized for that use-case and doesn't always play nice with backend/middle-tier testing needs.

For Node, I lean towards UVU by @lukeed due to its simplicity. Its lightweight, fast, supports ESM out of the box. It feels like an easier to setup modern Mocha (without the wide array of plugins).