Add Github action for CI

.github/workflows/ci.yml

@@ -0,0 +1,64 @@
+name: Tests
+
+on:
+  pull_request:
+    branches:
+      - '*'
+  push:
+    branches:
+      - main
+  workflow_call:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        ruby: ['3.0', '3.1', '3.2', '3.3']
+        gemfile:
+          - rails_6.0
+          - rails_6.1
+          - rails_7.0
+          - rails_7.1
+        # Example for excluding a specific Ruby version with a specific Gemfile
+        # exclude:
+        #   - ruby: '3.0'
+        #     gemfile: 'rails_7.1'
+
+    env:
+      BUNDLE_GEMFILE: ${{ github.workspace }}/gemfiles/${{ matrix.gemfile }}.gemfile
+      BUNDLE_PATH_RELATIVE_TO_CWD: true
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+          bundler: default
+          bundler-cache: true
+          rubygems: latest
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version-file: .node-version
+          cache: yarn
+          cache-dependency-path: './test/sample/yarn.lock'
+
+      - name: Node version
+        run: |
+          node --version
+
+      - name: Install NPM packages for sample app
+        run: |
+          bundle exec rake app:yarn_install_frozen
+
+      - name: StandardRb check
+        run: bundle exec standardrb
+
+      - name: Run tests
+        run: |
+          bundle exec rails db:test:prepare
+          bundle exec rails test