chai VS umd

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

Check out this fascinating GitHub project for more examples of UMD formats.

UMD (Universal Module Definition) is a set of tricky patterns to make your code file work in multiple environments.

Exports in a umd format so the library works everywhere.

A module format is the syntax we use to define a module. Different module formats such AMD, CommonJS, UMD and System.register have emerged in the past and a native module format is now available since ES6.

Supports circular references

To make UMD build available on both browsers and Node.js, set globalObject option to 'this'.

A modular system that your compiled application will use. You can choose: None, CommonJS, AMD, System, UMD, ES6, ES2015, ES2020 or ESNext. For backend apps/packages ES6 or CommonJS is suitable depending on Node.js version you want to support. For frontend apps ES6 is also suitable. And for support of older browsers and isomorphic applications, UMD is definitely worth choosing.