GitHub Actions test validator against list of sample files

[will-moore]

From discussion at #48 (comment)

It looks like it should be possible to use puppeteer https://pptr.dev/ to run tests from gh actions.

Questions:

• Where do we deploy the validator (built from the PR) for testing?

  • Use gh-pages? This works OK from a specific branch but is harder to setup from ALL branches / PRs
  • Use netlify? We already deploy there from PRs, but hard to sync that deployment with testing once it's ready
  • Use node to serve the pages "locally" from the test machine? This also needs a lot more investigation

• What do we want to test?

  • Check that "valid" samples show green check (and no errors)
  • Check that "valid" samples show other UI components?
  • Check that "invalid" samples show the X error if schema catches errors, and other error messages?

cc @joshmoore

[joshmoore]

but hard to sync that deployment with testing once it's ready

What does this mean? Sorry, I naively assumed the current netlify setup would have been fairly straight-forward. If not, then I can definitely see getting back to this later.

What do we want to test?

Green for known good and Red for known bad already sounds like a big win.

[will-moore]

Any job we have running on gh-actions won't know about the deployment from that PR that's running at netlify and won't know when it's ready to view (unless there's some way we can listen for the comments from netlify-bot on the PR.