workflow_run always evaluates to true

[gmyrianthous]

So I've tired paths-filter with the following triggers:

on:
  push:
    branches:
      - my-feature-branch

....

    - name: Capture changes
      uses: dorny/[email protected]
      id: changes
      with:
        filters: |
          my_first_path:
            - 'path/to/my_first_path**'
          my_second_path:
            - 'path/to/my_second_path/**'
          my_third_path:
            - 'path/to/my_third_path/**'

and the changes are identified correctly (say I made a change under path my_first_path:

Filter my_first_path = true
Filter my_second_path = false
Filter my_third_path = false

However, once I make the execution of this Worfklow dependent on the successful execution of another workflow

on:
    workflow_run:
        workflows: ["another workflow"]
        types: [completed]
    branches:
      - master

the filters applied with dorny/[email protected] always evaluate to true.

Note that this workflow gets executed once a Pull Requests gets merged to master (this is going to trigger a workflow whose successful completion will trigger the workflow I shared above).

Run dorny/[email protected]
Get current git ref
  /usr/bin/git branch --show-current
  master
Warning: 'before' field is missing in event payload - changes will be detected from last commit
Change detection in last commit
Detected 821 changed files
Results:
Filter my_first_path = true
Filter my_second_path = true
Filter my_third_path = true
Changes output set to ["my_first_path","my_second_path","my_third_path"]

Any thoughts what am I missing here?

[gmyrianthous]

@dorny Any thoughts?

[DpoBoceka]

Same behaviour with workflow_dispatch 🤔

[henrycpainter]

Events triggered by workflow_dispatch or workflows_run essentially don't have any context in them that can sensibly be assumed to be referred to as a "state before this change".

You can explicitly pass the paths filter base and ref which allows you to tell paths_filter what things to compare. To make that meaningful you'd probably want an input into the workflow_dispatch, or perhaps you can always generate the change base from say a known branch you want to compare.

I find this extremely useful: https://docs.github.com/en/actions/learn-github-actions/contexts#example-printing-context-information-to-the-log

To help find out what is in the event context that you might be able to pass as base and ref to the paths filter.

[DpoBoceka]

I personally ended up with a workaround:

- uses: dorny/paths-filter@v2
  id: paths-filter-init
  with:
    filters: |
      service1: services/service1/**
      service2: services/service2/**

- name: Hack-1
  # when event_name is workflow_dispatch or workflow_call, all the packages are set to true
  # so we want to return an empty json array instead as no files were changed
  id: hack-1
  env:
    GH_EVENT_NAME: ${{ github.event_name }}
  run: |
    case $GH_EVENT_NAME in
      workflow_dispatch)
        echo "::set-output name=paths-filter-final::'[]'"
        ;;

      workflow_call)
        echo "::set-output name=paths-filter-final::'[]'"
        ;;

      *)
        echo "::set-output name=paths-filter-final::'${{ toJSON(steps.paths-filter-init.outputs.changes) }}'"
        ;;
    esac

And declared paths-filter-final output so downstream jobs and steps could use that. If you skip paths-filter step entirely, you wouldn't have a valid json output

[ghost]

@DpoBoceka

Thanks for the workaround. However I doesn't work for me. I wasn't able to figure it out. When event_name is workflow_run all the packages are always set to true anyway. How do you declare paths-filter-final so it's true only if files are really changed ? A full example might be useful.

name: Deploy Test Second

on:
  workflow_run:
    workflows: ["Deploy Test First"]
    branches: [main]
    types: [completed]

jobs:
  changes-detection:
    runs-on: ubuntu-20.04
    outputs:
      changes: ${{ steps.paths-filter-workaround.outputs.paths-filter-final }}
    steps:
      - uses: actions/checkout@v3
      - uses: dorny/paths-filter@v2
        id: paths-filter-init
        with:
          filters: |
            test1:
              - "./testonefiledir1/testonefile1.yml"
              - "./testmultiplefilesdir1/**"
            test2:
              - "./testonefiledir2/testonefile2.yml"
              - "./testmultiplefilesdir2/**"

      - name: paths-filter-workaround
        id: workaround-1
        env:
          GH_EVENT_NAME: ${{ github.event_name }}
        run: |
          case $GH_EVENT_NAME in
            workflow_run)
              echo "::set-output name=paths-filter-final::'[]'"
              ;;

            *)
              echo "::set-output name=paths-filter-final::'${{ toJSON(steps.paths-filter-init.outputs.changes) }}'"
              ;;
          esac

dorny/paths-filter@v2 step log:

Run dorny/paths-filter@v2
Get current git ref
Warning: 'before' field is missing in event payload - changes will be detected from last commit
Change detection in last commit
Detected 9 changed files
Results:
Filter test1 = true
Filter test2 = true
Changes output set to ["test1","test2"]

paths-filter-workaround step log:

Run case $GH_EVENT_NAME in
  case $GH_EVENT_NAME in
    workflow_run)
      echo "::set-output name=paths-filter-final::'[]'"
      ;;
  
    *)
      echo "::set-output name=paths-filter-final::'"[\"test1\",\"test2\"]"'"
      ;;
  esac
  shell: /usr/bin/bash -e {0}
  env:
    GH_EVENT_NAME: workflow_run

[gki]

Hi. I faced the same issue and found a workaround. (It's not smart though... )

First of all, my workaround is passing Artifact between workflows. To do so, you must use action-download-artifact instead of the official actions/download-artifact, because the original one doesn't support download artifacts from another workflow.

Step 1. Save refs as artifact.

first-action.yml

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      (...omit...)
      - name: Save base ref info
        run: |
          if [[ '${{ github.event_name }}' == 'push' ]]; then
            BASE=${{ github.event.before }}
            CURRENT_BRANCH=${{ github.ref }}
          elif [[ '${{ github.event_name }}' == 'pull_request' ]]; then
            BASE=${{ github.base_ref }}
            CURRENT_BRANCH=${{ github.head_ref }}
          fi
          echo $BASE > base.txt
          echo $CURRENT_BRANCH > current-branch.txt
      - name: Upload base ref info
        uses: actions/upload-artifact@v3
        with:
          name: original-refs
          path: |
            base.txt
            current-branch.txt
          retention-days: 1

Step 2. Download them and set to base and ref.

second-aciton.yml

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - name: Download a single artifact
        uses: dawidd6/action-download-artifact@v2
        with:
          workflow: first-action.yml
          name: original-refs
          workflow_conclusion: success
      - name: set REF_BASE to env
        run: |
          echo "BASE=$(cat base.txt)" >> $GITHUB_ENV
          echo "CURRENT_BRANCH=$(cat current-branch.txt)" >> $GITHUB_ENV
      - uses: actions/checkout@v3
        with:
          ref: ${{ env.CURRENT_BRANCH }}
      - uses: dorny/paths-filter@v2
        id: filter
        with:
          base: ${{ env.BASE }}
          ref: ${{ env.CURRENT_BRANCH }}
          filters: |
            src:
              - src/**
            lib:
              - lib/**

The result is here, I've confirmed the output of workflow_run action is same with its first action. This workflow should work push and pull_request event. But you might need to adjust the contents of the artifact (BASE, CURRENT_BRANCH), if they are not suitable for your situation.

To check full yml, see my trial repo: https://github.com/gki/paths-filter-workflow-run-workaround