nox-testing.yml

name: tests
on:
  push:
  pull_request:
  workflow_dispatch:

jobs:
  list_nox_test_sessions:
    runs-on: ubuntu-latest
    steps:
        # (other steps before this: checkout code, install python and nox...)

        - name: list all test sessions
          id: set-matrix
          run: echo "::set-output name=matrix::$(nox -s gha_list -- tests)"

    # save the list into the outputs
    outputs:
      matrix: ${{ steps.set-matrix.outputs.matrix }}

  run_all_tests:
    needs: list_nox_test_sessions
    strategy:
      fail-fast: false
      matrix:
        nox_session: ${{ fromJson(needs.list_nox_test_sessions.outputs.matrix) }}
    name: Run nox session ${{ matrix.nox_session }}
    runs-on: ubuntu-latest
    steps:
      # (other steps before this: checkout code, install python)
      - run: nox -s "${{ matrix.nox_session }}"