Enable reporting results directly as a GitHub check

[andrewiggins]

Open questions:

1. Should results always be reported as a check in addition to the comment (if possible)
2. Should results only be reported as a check if comment failed?
3. Should results be reported as a check based on an action input?
4. Some combination of the above?

Right now I'm leaning towards 3.

IIRC, I think using the Checks API inside of an action will result in an additional check being reported in the checks list. In other words, if you run this action in a workflow called "benchmarks" and the check is called "benchmarks check", then in the list of checks at the bottom of the PR will include a "benchmarks" line item (representing that the workflow successfully completed) and a "benchmarks check" line item for the check the workflow manually created.

That duplicate line item probably doesn't impact lit-html as much since it runs all of it benchmarks in one workflow, but for Preact (which runs each benchmark in its own workflow) it would mean we'd have 8 line items related to benchmarks compared to 4. Hence I'm leaning to 3.

Relevant commit: 96645e6

[andrewiggins]

Another option to consider:

Add an option use-check that takes 3 values: always, never, on-forks with the default being on-forks.

• always: Always report as GitHub check
• never: Never report as GitHub check
• on-forks: If PR is opened is a fork, then report as check

To me, this seems to be the best cause it provides a smart default for people, but gives them the option to opt-out or always opt-in based on preference.