TestFramework

Mocha

• Discourage arrow function

Why Mocha

• No configuration required
• Smart align to nodejs (esm)

Why not mocha

• ts-mocha is not recognized by Webstorm
• No simple way to configure for mocha test framework for Typescript

JEST

• default test folder: __tests__. see in https://jestjs.io/docs/configuration#testregex-string--arraystring
• [ECMAScript Modules is disabled by default](see https://jestjs.io/docs/ecmascript-modules)
  • under Preview (06-Apr-2023)

Why Jest

• It takes care both nodejs and typescript
• It is widely used in Meta

Notes

• Replace assert.equal with assert.strictEqual