Dependencies Between Workflows on Github Actions

Now it's possible to have dependencies between workflows on Github Actions using workflow_run.

Using this config, the Release workflow will work when the Run Tests workflow is completed.

name: Release
on:
  workflow_run:
    workflows: ["Run Tests"]
    branches: [main]
    types: 
      - completed

You can (also) do it by combining workflow_run and if.

Using the below config, the deploy workflow will start only when all of these conditions are true:

1. after the test workflow is completed,
2. if the test workflow was successful,
3. Tere was a tag pushed to the default branch,

Assuming that the default branch is main:

name: deploy

on:
  # the 1st condition
  workflow_run:
    workflows: ["tests"]
    branches: [main]
    types:
      - completed

jobs:
  deploy-packages:
    # the 2nd condition
    if: ${{ github.event.workflow_run.conclusion == 'success' }}
    (...)

....BUT unfortunately the 3rd condition cannot be checked this way as the deploy workflow is triggered in a context of the HEAD of the default branch, without the knowledge about the tag that may be pointing there.

So doing something like:

    if: ${{ github.event.workflow_run.conclusion == 'success' }} && startsWith(github.ref, 'refs/tags/') }}

...will NOT work.

I will update this answer when I find out the workaround for this issue.

It seems that the Wait n Check action is currently the optimal workaround for this missing feature, as it declares in its README:

🎉 It allows to work around a GitHub Actions limitation of non-interdependent workflows (we can only depend on jobs inside a single workflow).

UPDATE: see also my other answer for a partial solution using workflow_run.