GH-1051 Add integrational tests

.github/workflows/test-mc-versions.yml

@@ -0,0 +1,99 @@
+name: MC Plugin Compatibility Test
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+jobs:
+  test-minecraft-versions:
+    runs-on: self-hosted
+    strategy:
+      fail-fast: false        
+      matrix:
+        mc_version: [1.18.2, 1.19.4, 1.20.6, 1.21.7]
+
+    env:
+      MC_VERSION: ${{ matrix.mc_version }}
+      PLUGIN_GLOB: "eternalcore-plugin/build/libs/EternalCore*.jar"
+      MC_PORT: 25560
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Set up JDK 21
+        uses: actions/setup-java@v4
+        with:
+          distribution: adopt
+          java-version: 21
+
+      - name: Make gradlew executable
+        run: chmod +x gradlew
+
+      - name: Build the plugin JAR
+        run: ./gradlew clean eternalcore-plugin:shadowJar
+
+      - name: Find plugin JAR
+        id: find-jar
+        run: |
+          PLUGIN_JAR=$(find ./eternalcore-plugin/build/libs -name 'EternalCore*.jar' | head -n1)
+          echo "PLUGIN_JAR=$PLUGIN_JAR" >> $GITHUB_ENV
+          if [ -z "$PLUGIN_JAR" ]; then
+            echo "❌ Plugin JAR not found!"
+            exit 1
+          fi
+
+      - name: Get latest PaperMC build number
+        id: get_build_number
+        run: |
+          BUILD_NUMBER=$(curl -s "https://api.papermc.io/v2/projects/paper/versions/${MC_VERSION}/builds" \
+            | jq '.builds | max_by(.build) | .build')
+          echo "build_number=$BUILD_NUMBER" >> $GITHUB_OUTPUT
+
+      - name: Setup PaperMC server for $MC_VERSION
+        run: |
+          mkdir mc-server
+          cd mc-server
+          wget "https://api.papermc.io/v2/projects/paper/versions/${MC_VERSION}/builds/${{ steps.get_build_number.outputs.build_number }}/downloads/paper-${MC_VERSION}-${{ steps.get_build_number.outputs.build_number }}.jar" \
+            -O paper.jar
+          mkdir plugins
+          cp "../$PLUGIN_JAR" plugins/
+
+      - name: Agree to EULA
+        run: echo "eula=true" > mc-server/eula.txt
+
+      - name: Configure server.properties
+        run: |
+          cat > mc-server/server.properties <<EOF
+          server-port=${MC_PORT}
+          allow-nether=false
+          level-type=FLAT
+          max-world-size=16
+          EOF
+
+      - name: Configure bukkit.yml
+        run: |
+          cat > mc-server/bukkit.yml <<EOF
+          settings:
+            allow-end: false
+          EOF
+
+      - name: Run server and fail on errors
+        working-directory: mc-server
+        run: |
+          java -Xmx1G -jar paper.jar nogui > server.log 2>&1 &
+          PID=$!
+          echo "Started MC ${MC_VERSION} on port ${MC_PORT} (PID=${PID})"
+          sleep 60
+          kill $PID || true
+          wait $PID || true
+          if grep -iE 'error|exception|failed' server.log; then
+            echo "❌ Errors detected in server.log"
+            cat server.log
+            exit 1
+          else
+            echo "✅ No errors detected for MC ${MC_VERSION}"
+          fi