test.yaml

name: Build and Test Julia Package

on:
  # Every pull request, whatever its base, so a PR stacked on another feature branch
  # is tested too; it is tested again once retargeted, when it syncs with develop.
  pull_request:
  merge_group:
    types: [checks_requested]
  push:
    branches:
      - main
      - develop

permissions:
  contents: read

concurrency:
  # One in-flight run per branch/PR. Superseded pull request runs are cancelled;
  # Push and queue runs finish independently on their own refs.
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: ${{ github.event_name == 'pull_request' }}

jobs:
  changes:
    name: Detect Julia changes
    runs-on: ubuntu-slim
    timeout-minutes: 5
    permissions:
      contents: read
      pull-requests: read
    outputs:
      julia: ${{ steps.filter.outputs.julia }}
    steps:
      - name: Check whether the pull request touches Julia code
        id: filter
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          REPO: ${{ github.repository }}
          PR_NUMBER: ${{ github.event.pull_request.number }}
          EVENT_NAME: ${{ github.event_name }}
        run: |
          set -euo pipefail

          # Report the decision to the job log as well as the run summary, so
          # `why did/didn't this run?` is answerable from either one.
          say() { echo "$1"; echo "$1" >> "$GITHUB_STEP_SUMMARY"; }

          # Pushes and queue candidates always run the full battery.
          if [ "$EVENT_NAME" != "pull_request" ]; then
            echo "julia=true" >> "$GITHUB_OUTPUT"
            say "Event $EVENT_NAME — running the full test suite."
            exit 0
          fi

          files=$(gh api --paginate "repos/${REPO}/pulls/${PR_NUMBER}/files" --jq '.[].filename')

          # Allowlist of what test/runtests.jl actually exercises: the package
          # itself, the tests and their fixtures, the example decks the tests run
          # end-to-end, the dependency set (declared in Project.toml and pinned in
          # ci/manifests), and this workflow. Anything not listed here does not
          # trigger a run, so new untested Julia (benchmarks, docs scripts, a
          # future tools/ directory) is excluded by default rather than by
          # remembering to exclude it.
          tested='(^src/|^test/|^examples/|^ci/manifests/|^ci/local-julia-cache\.sh$|^Project\.toml$|^\.github/workflows/(test|julia-test-version)\.yaml$)'

          relevant=$(printf '%s\n' "$files" | grep -E "$tested" || true)

          say "### Julia change detection"
          say ""
          if [ -n "$relevant" ]; then
            say "Running the test suite. Matched files:"
            say '```'
            say "$relevant"
            say '```'
          else
            say "No Julia code, test data or example decks changed — skipping the test suite."
            say ""
            say "Files considered:"
            say '```'
            say "$files"
            say '```'
          fi

          if [ -n "$relevant" ]; then
            echo "julia=true" >> "$GITHUB_OUTPUT"
          else
            echo "julia=false" >> "$GITHUB_OUTPUT"
          fi

  test:
    name: Julia ${{ matrix.version }}
    needs: changes
    if: needs.changes.outputs.julia == 'true'
    strategy:
      fail-fast: false
      matrix:
        version: ['1.11', '1.x']
    uses: ./.github/workflows/julia-test-version.yaml
    with:
      version: ${{ matrix.version }}

  # Stable check that is present on every pull request, whether or not the suite
  # ran. Point branch protection at this job so skipped runs do not block merges.
  test-status:
    name: Tests
    needs: [changes, test]
    if: always()
    runs-on: ubuntu-slim
    timeout-minutes: 5
    steps:
      - name: Report suite result
        run: |
          set -euo pipefail
          if [ "${{ needs.changes.result }}" != "success" ]; then
            echo "Change detection failed; cannot tell whether tests were needed."
            exit 1
          fi
          case "${{ needs.test.result }}" in
            success) echo "Test suite passed." ;;
            skipped) echo "No Julia code changed; test suite intentionally skipped." ;;
            *)       echo "Test suite result: ${{ needs.test.result }}"; exit 1 ;;
          esac