add build.yml

.github/workflows/build.yml

@@ -0,0 +1,71 @@
+name: Build
+
+on:
+  push:
+  pull_request:
+    types:
+      - opened
+      - reopened
+      - synchronize
+      - labeled
+
+jobs:
+  build:
+    # 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 build-pr-jar flag.
+    # This snippet was taken from Paper's workflow.
+    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 == 'build-pr-jar')
+      )
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v4
+
+      - name: Validate Gradle Wrapper
+        uses: gradle/actions/wrapper-validation@v3
+
+      - name: Setup Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: 21
+
+      - name: Setup Gradle
+        uses: gradle/actions/setup-gradle@v4
+        with:
+          gradle-version: current
+
+      - name: Build with Gradle
+        run: ./gradlew build
+
+      - name: Upload Artifact
+        id: upload
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{ github.event.repository.name }} Build
+          path: build/libs
+
+      - name: Find Comment
+        uses: peter-evans/find-comment@v4
+        id: fc
+        with:
+          issue-number: ${{ github.event.pull_request.number }}
+          comment-author: 'github-actions[bot]'
+
+      - name: Create or update comment
+        uses: peter-evans/create-or-update-comment@v4
+        with:
+          comment-id: ${{ steps.fc.outputs.comment-id }}
+          issue-number: ${{ github.event.pull_request.number }}
+          body: |
+            Build output
+            ${{ steps.build.outputs.build-log }}
+          edit-mode: replace