How can I skip the whole job for a matrix match in github action?

Question

I am using matrix to trigger workflow jobs in github action. The apps from affected-apps output gives me the array including all affected app name. There could be a hundred apps returned in this array.

But I just want to select a few of them. I tried to use if: ${{ contains(fromJson('["app1", "app2"]'), matrix.app) }} on job root level but it gives me error. It only works if I put the condition under stpes. But I have to put this condition on every step which is not good.

Is there a way to only select a few matched matrix on job level?

I know there is exclude on matrix can do the job, but I have a long list of exclude. I'd like to choose only include on matrix. How can I achieve that?

jobs:
  example_matrix:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        app: ${{ fromJson(needs.affected-apps.outputs.apps) }}
    if: ${{ contains(fromJson('["app1", "app2"]'), matrix.app) }}
    steps:
      - uses: actions/setup-node@v3
      - uses: ...
      - uses: ...
      - uses: ...

Answer 1

You can introduce temporary step where you use jq to filter out not needed variations like here:

jobs:
  affected-apps:
    runs-on: ubuntu-latest
    name: A job to say hello
    outputs:
        apps: ${{ steps.step1.outputs.test}}
    steps:
      - uses: actions/checkout@v3
      - id: step1
        run: echo 'test=["app1","app2", "app3"]' >> "$GITHUB_OUTPUT"
  example_matrix:
    runs-on: ubuntu-latest
    needs: affected-apps
    strategy:
      matrix:
        app: ${{ fromJson(needs.affected-apps.outputs.apps) }}
    steps:
      - uses: actions/setup-node@v3
      - run: echo "${{ matrix.app }}"
  filter_matrix:
    runs-on: ubuntu-latest
    needs: affected-apps
    outputs:
        apps: ${{ steps.step1.outputs.filtered }}
    steps:
      - id: step1
        run: | 
            echo "$APPS"
            RESULT=$(echo $APPS | jq -c --argjson toRemove '["app1", "app2"]' 'map(select(. as $v | $toRemove | index($v) | not))')
            echo "$RESULT"
            echo "filtered=$RESULT" >> "$GITHUB_OUTPUT"
        env:
         APPS: ${{ needs.affected-apps.outputs.apps }}
  filtered_matrix:
    runs-on: ubuntu-latest
    needs: filter_matrix
    strategy:
      matrix:
        app: ${{ fromJson(needs.filter_matrix.outputs.apps) }}
    steps:
      - uses: actions/setup-node@v3
      - run: echo "${{ matrix.app }}"