How to test new Github Actions workflows

I recently build out a data processing pipeline that uses Github Actions, and so needed to add several new workflows. I couldn’t for the life of me figure out how to test them. They were going to be initiated either as part of a pipeline (using workflow_call), or manually, using workflow_dispatch. In most cases, each workflow had inputs which needed to be provided.

Github Actions shows workflows that can be called, but only once they’re on main. I didn’t really want to sit here committing directly to main until they worked the way I needed, so I came up with this flow which works well:

1. Create the workflow files you need. Make sure they have the workflow_dispatch trigger at least so they can be invoked
2. Put a minimal job into the workflow file - it doesn’t matter what the job does, it just needs to be syntactically valid
3. Via a pull request, add these new workflows to main- noting that they are basically no-op workflows at the moment
4. Now that the workflows are on main, they are available to be dispatched from the Github Actions UI, and you can now choose which branch to run the workflow from.
5. Modify your workflow on a branch, committing as necessary and invoking the workflow from that branch.
6. Once you have the workflow working the way you expect, you can open a pull request to add the ‘implementation’ of the workflow back to ‘main’.

This pattern still requires a pull request onto main, but only with no-op, ‘empty’ workflows. Once they are on main, they can be actually implemented and tested in a feature branch before merging the implementation back to main.