This issue about moving away from Jest to Node.js's Native Test Runner

Why

It would be great if we adopted Node.js's Test Runner (and moved away from Jest) because:

• Way less dependencies
  • We only need JSDom to be set before the tests start running
    • https://github.com/nodejs/nodejs.org/blob/main/jest.setup.mjs
  • We can remove all the reporters/coverage generators and other dependencies
• It's way faster and native to Node.js
• It's natively ESM compatible which Jest isn't
• We don't need snapshots nor any fancy Jest functionality

Migration

• We still generate JUnit Test Reports for our GitHub Action
  • https://nodejs.org/api/test.html#test-reporters
• Mocking of Modules cannot be done on "module name mapping" (https://github.com/nodejs/nodejs.org/blob/main/jest.config.mjs#L15-L17)
  • Meaning the mocks we have on __mocks__ folders need to be manually imported when used and need to be changed to use the Mocking API https://nodejs.org/api/test.html#mocking
• Any usage of jest. APIs need to be replaced to Node Test Runners APIs
  • https://nodejs.org/api/test.html
• Any usage of expect needs to be changed to assert (https://nodejs.org/api/assert.html)
• Some pieces of code/tests might also need to be changed