Nested composite actions

I would like to be able to create a composite action that contains other composite actions. This does not seem to currently work.

For example, there are four steps that go into installing Python and using pipenv to install and cache dependencies. I’d like to create a single composite action that does everything involved so I don’t have to reproduce all of the steps in each of my workflows. I imagine such an action would look like this:

name: 'Python and pipenv installer'
description: 'Install all the things with Python and pipenv'
inputs:
  python-version:
    description: 'The version of Python to install'
    required: false
    default: 3.8
runs:
  using: "composite"
  steps: 
    - id: install-python
      name: Install Python 3.8
      uses: actions/setup-python@v2
      with:
        python-version: ${{ inputs.python-version }}

    - id: install-pipenv
      name: Install pipenv
      run: |
          python -m pip install --upgrade --no-cache-dir pip
          python -m pip install --no-cache-dir pipenv
      shell: bash
   
    - id: cache-dependencies
      name: Cache dependencies
      uses: actions/cache@v2
      with:
        path: |
          ~/.cache/pip
          ~/.cache/pipenv
        key: ${{ runner.os }}-pipenv-${{ hashFiles('Pipfile.lock') }}
        restore-keys: |
          ${{ runner.os }}-pipenv-
          ${{ runner.os }}-

    - id: sync-pipfile
      name: Install dependencies with pipenv
      run: pipenv sync  
      shell: bash

However, that does not seem to work. I get an error complaining like this when I try to use it.

Error: datadesk/python-pipenv-installer-action/v3/action.yaml (Line: 13, Col: 7): Unexpected value 'uses'
Error: datadesk/python-pipenv-installer-action/v3/action.yaml (Line: 14, Col: 7): Unexpected value 'with'
Error: datadesk/python-pipenv-installer-action/v3/action.yaml (Line: 11, Col: 7): Required property is missing: run
Error: datadesk/python-pipenv-installer-action/v3/action.yaml (Line: 11, Col: 7): Required property is missing: shell
Error: datadesk/python-pipenv-installer-action/v3/action.yaml (Line: 26, Col: 7): Unexpected value 'uses'
Error: datadesk/python-pipenv-installer-action/v3/action.yaml (Line: 27, Col: 7): Unexpected value 'with'
Error: datadesk/python-pipenv-installer-action/v3/action.yaml (Line: 24, Col: 7): Required property is missing: run
Error: datadesk/python-pipenv-installer-action/v3/action.yaml (Line: 13, Col: 7): Unexpected value 'uses'
Error: datadesk/python-pipenv-installer-action/v3/action.yaml (Line: 14, Col: 7): Unexpected value 'with'
Error: datadesk/python-pipenv-installer-action/v3/action.yaml (Line: 11, Col: 7): Required property is missing: run
Error: datadesk/python-pipenv-installer-action/v3/action.yaml (Line: 11, Col: 7): Required property is missing: shell
Error: datadesk/python-pipenv-installer-action/v3/action.yaml (Line: 26, Col: 7): Unexpected value 'uses'
Error: datadesk/python-pipenv-installer-action/v3/action.yaml (Line: 27, Col: 7): Unexpected value 'with'
Error: datadesk/python-pipenv-installer-action/v3/action.yaml (Line: 24, Col: 7): Required property is missing: run
Error: System.ArgumentException: Unexpected type '' encountered while reading 'steps item uses'. The type 'StringToken' was expected.

My presumption is that this means I can’t have composite actions inside my composite. I suspect this is a common use case and I’d love to see a solution of some form.

[thboop]

We are hoping to support this soon, up to a certain depth level of ~9 or so. I’ll follow up with more information once this is live.

[make-github-pseudonymous-again]

Thanks for landing this! When refactoring a workflow where shell is absent from a run step one needs to be explicit about shell. Is bash the recommended default? What would be the most generic explicit setting?