Ship JRuby gem pre-built

Use Github-Actions to build gems for **all conceivable versions**.

Fixes ConradIrwin#22

Signed-off-by: Stavros Ntentos <[email protected]>

.github/workflows/build-gems.yml

@@ -0,0 +1,98 @@
+name: Buildpy JRuby Gem
+
+on:
+  push:
+  pull_request:
+  release:
+    types:
+      - published
+
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 10
+
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - ubuntu-latest
+        ruby-version:
+          - 'head'
+          - '3.4'
+          - '3.3'
+          - '3.2'
+          - '3.1'
+          - '3.0'
+          - '2.7'
+          - '2.6'
+          - '2.5'
+          - '2.4'
+          - '2.3'
+          - '2.2'
+          - '2.1'
+          - '2.1.0'
+          - '2.0.0'
+          - '1.9'
+          - '1.9.3'
+          - '1.9.2'
+          # - '1.8(.7)'
+          - 'jruby-head'
+          - 'jruby-9.4'
+          - 'jruby-9.3'
+          - 'jruby-9.2'
+          - 'jruby-9.1'
+          # - 'jruby-1[89]mode'
+          - truffleruby-24
+          - truffleruby-23
+          - truffleruby-22
+          - truffleruby-21
+          - truffleruby-20
+          - truffleruby-19
+          - truffleruby+graalvm-24
+          - truffleruby+graalvm-23
+          - truffleruby+graalvm-22
+          - truffleruby+graalvm-21
+          # - rbx ?
+          # - ree ?
+
+    defaults:
+      run:
+        shell: /bin/bash --noprofile --norc -Eeuxo pipefail {0}
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      - name: Set up JRuby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby-version }}
+          bundler-cache: true
+
+      - name: Slugify GITHUB_REPOSITORY
+        run: echo "GITHUB_REPOSITORY_SLUG=${GITHUB_REPOSITORY////_}" >> $GITHUB_ENV
+
+      - name: Build JRuby Extension
+        run: |
+          # Use your build tool (e.g., Maven, Gradle) to build the extension into a JAR
+          # For example, if using Gradle:
+          ./gradlew build
+
+      - name: Package Gem with Pre-built JAR
+        run: rake build
+
+      - name: Run Tests
+        run: |
+          bundle exec rake test
+
+      - name: Build Gem
+        run: gem build your_gem.gemspec
+
+      - name: Create artifacts
+        uses: actions/upload-artifact@v4
+        if: ${{ !cancelled() }}
+        with:
+          name: ${{ env.GITHUB_REPOSITORY_SLUG }}_${{ github.event_name }}_${{ github.event.pull_request.number || github.sha }}_${{ matrix.os
+            }}_ruby-${{ matrix.ruby-version }}_gems
+          path: ${{ github.event.repository.name }}-*.gem