Added Jest and Playwright test support to Next.js server

I spent some time today configuring Jest for unit testing and Playwright for end-to-end tests for my Next.js server. Both were quite easy to install.

Next actually comes preconfigured with (experimental) Jest support, so all that was required was to add 'jest.config.js' and 'jest.setup.js' files. Details can be found here: Setting up Jest (with the Rust Compiler).

Setting up Playwright was even easier. I just followed the tutorial here: Playwright.

To get Playwright to work with Github Actions I needed to uncomment the following lines in 'playwright.config.js':

/* Run your local dev server before starting the tests */
webServer: {
  command: 'npm run dev',
  port: 3000,
},

And then finally to make Jest and Playwright play nice together, I needed to exclude the default Playwright "tests" directory from Jest's coverage by doing this:

// Add any custom config to be passed to Jest
const customJestConfig = {
  ...
  // Ignore the E2E (Playwright) tests ... TODO should probably use a different directory name
  modulePathIgnorePatterns: ["tests"]
}

Using the tutorials from the Next page made these jobs pretty easy.