Add initial unit and integration tests for CLI and mochify

[mantoni]

This adds a few unit tests for the mochify module and some integration tests for the mochify and cli modules and runs them with GitHub actions.

Ref #229

[m90]

Is this just for saving some CPU cycles (running it once will be enough) or is there some other reason to it?

[mantoni]

Yep. Build speed as well. An alternative could be running lint and prettier in a separate job, but then it needs a to run npm install again.

[m90]

I wonder if this could turn into a red herring for people that don't know about this and have a build that fails on Node 16, but passes on Node 14, and who then go spelunking in changelogs and everything instead of having a look at the build output.

Probably ok to do it like this still.

[m90]

Did Firefox do strange things in CI or is this just for speed?

[mantoni]

There is no Firefox in the GitHub action container installed. However, chromium is. We'd need to figure out how to install Firefox, but then I thought it's not important for the purpose of this test.

[m90]

I was under the impression that Playwright installs all supported engines on postinstall so I am surprised this does not work. It does however place the executable outside of node_modules (as opposed to puppeteer), so maybe this needs some npm caching and/or $PATH adjustments in our context. I can look at that myself if you don't feel like doing it here.

See:

• https://playwright.dev/docs/ci#github-actions
• https://playwright.dev/docs/ci#caching-browsers

[mantoni]

I might have changed too many things at once when I tried to get the build working.

[mantoni]

I gave this another try and integration tests time out when I configure firefox as the engine. I'll merge this now and we can look into it separately. Once we have a solution locally and for GitHub Actions, we can document the setup in driver-playwright/README.md.