build.yaml

# Here lie dragons!
#
# This action either builds the server or
# builds a paperclip jar to be updated in the body
# of the PR relating to this action.

name: Build Paper

on:
  pull_request:
    types:
      - opened
      - reopened
      - synchronize
      - labeled
  push:
    branches-ignore:
      - main

jobs:
  build:
    env:
      ORG_GRADLE_PROJECT_paperBuildCacheEnabled: true
      ORG_GRADLE_PROJECT_paperBuildCacheUsername: ${{ secrets.PAPER_BUILD_CACHE_USERNAME }}
      ORG_GRADLE_PROJECT_paperBuildCachePassword: ${{ secrets.PAPER_BUILD_CACHE_PASSWORD }}
      ORG_GRADLE_PROJECT_paperBuildCachePush: true

    # The goal of the build workflow is split into multiple requirements.
    # 1. Run on pushes to same repo.
    # 2. Run on PR open/reopen/syncs from repos that are not the same (PRs from the same repo are covered by 1)
    # 3. Run on labeled PRs that have the publish-pr flag.
    if: >
      (
        (github.event_name == 'push')
        || (github.event_name == 'pull_request' && github.repository != github.event.pull_request.head.repo.full_name && contains(fromJSON('["opened", "reopened", "synchronize"]'), github.event.action))
        || (github.event_name == 'pull_request' && github.event.action == 'labeled' && github.event.label.name == 'publish-pr')
      )

    runs-on: ubuntu-latest
    steps:
      - if: ${{ github.event_name == 'push' }}
        uses: actions/checkout@v7
        with:
          # todo remove me again after the update
          ref: ${{ github.ref_name }}
          fetch-depth: 0
      - if: ${{ github.event_name == 'pull_request' }}
        uses: actions/checkout@v7
        with:
          ref: ${{ github.event.pull_request.head.sha }}
      - name: JDK 25
        uses: actions/setup-java@v5
        with:
          java-version: 25
          distribution: 'zulu'

      - name: Setup Gradle
        uses: gradle/actions/setup-gradle@v6
        with:
          # Allow cache writes on main and dev branches
          cache-read-only: ${{ github.ref != 'refs/heads/main' && !startsWith(github.ref, 'refs/heads/dev/') }}

      - name: Configure Build
        uses: actions/github-script@v9
        id: determine
        env:
          REF_NAME: "${{ github.ref_name }}"
          REF_TYPE: "${{ github.ref_type }}"
          EVENT: "${{ toJSON(github.event) }}"
          EVENT_TYPE: "${{ github.event_name }}"
        with:
          script: |
            const {owner, repo} = context.repo;
            const event_name = `${process.env.EVENT_TYPE}`;
            const event = JSON.parse(`${process.env.EVENT}`);
            const ref_type = `${process.env.REF_TYPE}`;
            const ref_name = `${process.env.REF_NAME}`;
            const result = {
              action: "build"
            };

            if (event_name === "push" && ref_type === "branch") {
              const {data: pulls} = await github.rest.pulls.list({ owner, repo, head: `${owner}:${ref_name}`, state: "open" });
              const pull = pulls.find((pr) => !!pr.labels.find((l) => l.name === "publish-pr"));
              if (pull) {
                result["pr"] = pull.number;
                result["action"] = "paperclip";
                core.notice(`This is a push action but to a branch with an open PR with the build paperclip label (${JSON.stringify(result)})`);
                return result;
              }
            } else if (event_name === "pull_request" && event.pull_request.labels.find((l) => l.name === "publish-pr")) {
              result["pr"] = event.pull_request.number;
              result["action"] = "paperclip";
              core.notice(`This is a pull request action with a build paperclip label (${JSON.stringify(result)})`);
              return result;
            }
            core.notice("This will not build a paperclip jar");
            return result;

      - name: Apply Patches
        run: |
          git config --global user.email "no-reply@github.com"
          git config --global user.name "GitHub Actions"
          ./gradlew applyPatches --stacktrace

      - name: Build
        run: ./gradlew build --stacktrace

      - name: Upload Test Results
        if: always()
        uses: actions/upload-artifact@v7
        with:
          name: test-results
          path: |
            **/build/test-results/test/TEST-*.xml

      - name: Publish Checkstyle Report
        uses: Juuxel/publish-checkstyle-report@v3
        if: failure() || success()
        with:
          reports: |
            */build/reports/checkstyle/*.xml

      - name: Create Paperclip Jar
        if: fromJSON(steps.determine.outputs.result).action == 'paperclip'
        run: ./gradlew createPaperclipJar --stacktrace

      - name: Upload Paperclip Jar
        if: fromJSON(steps.determine.outputs.result).action == 'paperclip'
        uses: actions/upload-artifact@v7
        with:
          name: paper-${{ fromJSON(steps.determine.outputs.result).pr }}
          path: paper-server/build/libs/paper-paperclip-*.jar

      - name: Publish Artifacts
        if: fromJSON(steps.determine.outputs.result).action == 'paperclip'
        uses: PaperMC/action-pr-publishing/upload@paper
        with:
          # TODO fallback for failing javadoc
          publishing-task: ":paper-api:publishAllPublicationsTo_githubPackages_PRsRepository publishDevBundlePublicationTo_githubPackages_PRsRepository -PpublishDevBundle"
  event_file:
    name: "Event File"
    needs: build
    if: ${{ !cancelled() && needs.build.result != 'skipped' }}
    runs-on: ubuntu-latest
    steps:
      - name: Upload
        uses: actions/upload-artifact@v7
        with:
          name: event-data
          path: ${{ github.event_path }}