automate testing for actions

[kelly-sovacool]

GitHub Actions does not let you set actions versions dynamically, i.e. this does not work:

- uses: CCBR/actions/my-action@${{ inputs.version }}

Which means it may not be possible to automatically test github actions defined in this repo.

Perhaps a workaround is to trigger creation of a workflow file with the github sha? But it would need to be committed in order to run, which would clutter up the repo. Maybe do this in a separate repo? But how will status checks then show up in PRs for this repo?

It seems most people recommend having the majority of the workflow logic outside of actions so those pieces can be tested. But even so it would be ideal to test the action itself, as not everything can be broken out into separate scripts.