build: implement github actions

.github/workflows/dev-jar.yml

@@ -0,0 +1,30 @@
+name: Build DEV Jars
+
+on: [push, pull_request]
+
+jobs:
+  build_dev_jars:
+    name: Build DEV jars
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+      - name: Setup JDK
+        uses: actions/setup-java@v2
+        with:
+          distribution: 'adopt'
+          java-version: '8'
+      - name: Build with Gradle
+        run: |
+          ./gradlew jar snapshotVersion
+           git_hash=$(git rev-parse --short "$GITHUB_SHA")
+           echo "git_hash=$git_hash" >> $GITHUB_ENV
+           echo "snapshotVersion=$(cat build/versions/snapshot.txt)" >> $GITHUB_ENV
+           echo "artifactPath=$(pwd)/build/libs" >> $GITHUB_ENV
+      - name: Upload Plugin jar
+        uses: actions/upload-artifact@v3
+        with:
+          name: SimpleJoinMessage-${{ env.snapshotVersion }}-${{ env.git_hash }}.jar
+          path: ${{ env.artifactPath }}/SimpleJoinMessage-${{ env.snapshotVersion }}.jar

build.gradle

@@ -1,3 +1,5 @@
+import java.nio.file.Files
+
 plugins {
     id 'com.github.johnrengelman.shadow' version '7.1.2'
     id 'kr.entree.spigradle' version '2.4.2'
@@ -131,3 +133,17 @@ tasks {
         relocate("kotlin", "${libsPackage}.kotlin")
     }
 }
+
+abstract class PrintSnapshotVersionTask extends DefaultTask {
+    @TaskAction
+    def print() {
+        File versionsDir = project.file("$project.buildDir/versions")
+        File textFile = project.file("$project.buildDir/versions/snapshot.txt")
+        versionsDir.mkdirs()
+        Files.deleteIfExists(textFile.toPath())
+        textFile.createNewFile()
+        textFile << "$project.version"
+    }
+}
+
+tasks.register('snapshotVersion', PrintSnapshotVersionTask)