Dependencies Between Workflows on Github Actions

I have a monorepo with two workflows:

.github/workflows/test.yml

name: test

on: [push, pull_request]

jobs:
  test-packages:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v1
      - name: test packages
        run: |
          yarn install
          yarn test
...

.github/workflows/deploy.yml

name: deploy

on:
  push:
    tags:
      - "*"

jobs:
  deploy-packages:
    runs-on: ubuntu-latest
    needs: test-packages
    steps:
      - uses: actions/checkout@v1
      - name: deploy packages
        run: |
          yarn deploy
        env:
          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
...

This doesn't work, I can't reference a job in another workflow:

### ERRORED 19:13:07Z

- Your workflow file was invalid: The pipeline is not valid. The pipeline must contain at least one job with no dependencies.

Is there a way to create a dependency between workflows?

What I want is to run test.yml then deploy.yml on tags, and test.yml only on push and pull requests. I don't want to duplicate jobs between workflows.

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.

This is possible with a combination of workflow_call and needs. Adding workflow_call to the on values of a job allows it to be called by other jobs. You can then call that job from the other workflow, and use needs to force future steps to depend on the success of that job. You can read about making workflows callable here: https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#onworkflow_call and requiring a step to succeed before triggering future steps here: https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idneeds

So for your case, the following should work:

# cat .github/workflows/tests.yml
name: tests
on: [workflow_call]  # allow this workflow to be called from other workflows
jobs:
  ...

# cat .github/workflows/deploy.yml
name: deploy
on:
  push:
    tags:  # trigger the deploy job on tag creation
    - *
jobs:
  tests:
    uses: ./.github/workflows/tests.yml  # use the callable tests job to run tests
  deploy:
    name: deploy
    needs: [tests]  # require tests to pass before deploy runs
    ...

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.

You can create reusable workflows: https://docs.github.com/en/actions/using-workflows/reusing-workflows.