ci.yml

name: CI

on:
  push:
    branches: [master]
  pull_request:
  workflow_dispatch:

# A second push to the same branch makes the first run's answer stale, and a real-tmux suite is too
# expensive to keep running for an answer nobody will read.
# Cancel a superseded run only on a pull request, where a new push genuinely replaces the answer.
# On master every commit's run stands on its own: grouping them all together meant re-running an
# older commit cancelled the newest one, which is the opposite of what a green history needs.
concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}-${{ github.event_name == 'pull_request' && github.ref || github.sha }}
  cancel-in-progress: ${{ github.event_name == 'pull_request' }}

permissions:
  contents: read

jobs:
  check:
    name: check (JDK ${{ matrix.java }})
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        # 21 is the baseline the library compiles against; the newest LTS is here because a library
        # is run on JDKs its author never chose, and the ones that break it break at runtime.
        java: ['21', '25']
    steps:
      - uses: actions/checkout@v7

      - name: Install tmux
        run: |
          sudo apt-get update
          sudo apt-get install --no-install-recommends -y tmux
          tmux -V

      - uses: actions/setup-java@v5
        with:
          distribution: temurin
          java-version: ${{ matrix.java }}

      - uses: gradle/actions/setup-gradle@v6
        with:
          # The wrapper jar is a binary this repository executes, so its checksum is verified against
          # the ones Gradle published rather than trusted because it is committed here.
          validate-wrappers: true

      - run: ./gradlew check --stacktrace

      # A real-tmux suite that leaves servers running would be invisible here and expensive on a
      # developer's machine. The runner is discarded either way, so this is the only place the
      # question gets asked for free.
      - name: No tmux server outlived the suite
        if: always()
        run: |
          left="$(pgrep -c tmux || true)"
          if [ "${left:-0}" -ne 0 ]; then
            echo "::error::$left tmux server(s) survived the suite"
            for p in $(pgrep tmux); do tr '\0' ' ' < "/proc/$p/cmdline"; echo; done
            exit 1
          fi
          echo "no tmux server survived the suite"

      - name: Publish to a local repository
        run: ./gradlew publishToMavenLocal --stacktrace

      - uses: actions/upload-artifact@v7
        if: failure()
        with:
          name: reports-jdk${{ matrix.java }}
          path: '**/build/reports/**'
          retention-days: 7