Add GitHub Workflow

.github/workflows/tests.yml

@@ -0,0 +1,117 @@
+name: tests
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - ruby: 2.4
+            rails: ~> 4.2.0
+          - ruby: 2.4
+            rails: ~> 5.0.0
+          - ruby: 2.4
+            rails: ~> 5.1.0
+          - ruby: 2.4
+            rails: ~> 5.2.0
+
+          - ruby: 2.5
+            rails: ~> 5.0.0
+          - ruby: 2.5
+            rails: ~> 5.1.0
+          - ruby: 2.5
+            rails: ~> 5.2.0
+          - ruby: 2.5
+            rails: ~> 6.0.0
+          - ruby: 2.5
+            rails: ~> 6.1.0
+          - ruby: 2.5
+            rails: edge
+
+          - ruby: 2.6
+            rails: ~> 5.0.0
+          - ruby: 2.6
+            rails: ~> 5.1.0
+          - ruby: 2.6
+            rails: ~> 5.2.0
+          - ruby: 2.6
+            rails: ~> 6.0.0
+          - ruby: 2.6
+            rails: ~> 6.1.0
+          - ruby: 2.6
+            rails: edge
+
+          - ruby: 2.7
+            rails: ~> 5.0.0
+          - ruby: 2.7
+            rails: ~> 5.1.0
+          - ruby: 2.7
+            rails: ~> 5.2.0
+          - ruby: 2.7
+            rails: ~> 6.0.0
+          - ruby: 2.7
+            rails: ~> 6.1.0
+          - ruby: 2.7
+            rails: ~> 7.0.0
+          - ruby: 2.7
+            rails: ~> 7.1.0
+          - ruby: 2.7
+            rails: edge
+
+          - ruby: 3.0
+            rails: ~> 6.0.0
+          - ruby: 3.0
+            rails: ~> 6.1.0
+          - ruby: 3.0
+            rails: ~> 7.0.0
+          - ruby: 3.0
+            rails: ~> 7.1.0
+          - ruby: 3.0
+            rails: edge
+
+          - ruby: 3.1
+            rails: ~> 6.0.0
+          - ruby: 3.1
+            rails: ~> 6.1.0
+          - ruby: 3.1
+            rails: ~> 7.0.0
+          - ruby: 3.1
+            rails: ~> 7.1.0
+          - ruby: 3.1
+            rails: edge
+
+          - ruby: 3.2
+            rails: ~> 6.0.0
+          - ruby: 3.2
+            rails: ~> 6.1.0
+          - ruby: 3.2
+            rails: ~> 7.0.0
+          - ruby: 3.2
+            rails: ~> 7.1.0
+          - ruby: 3.2
+            rails: edge
+
+          - ruby: head
+            rails: ~> 6.0.0
+          - ruby: head
+            rails: ~> 6.1.0
+          - ruby: head
+            rails: ~> 7.0.0
+          - ruby: head
+            rails: ~> 7.1.0
+          - ruby: head
+            rails: edge
+
+    env:
+      RAILS_VERSION: ${{ matrix.rails }}
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: ${{ matrix.ruby }}
+        bundler-cache: true
+    - name: Run tests
+      run: rake

Gemfile

@@ -2,9 +2,11 @@ source "https://rubygems.org"
 
 # rubocop:disable Bundler/DuplicatedGem
 if ENV["RAILS_VERSION"]
-  gem "rails", ENV["RAILS_VERSION"]
-elsif ENV["RAILS_BRANCH"]
-  gem "rails", git: "https://github.com/rails/rails.git", branch: ENV["RAILS_BRANCH"]
+  if ENV["RAILS_VERSION"] == "edge"
+    gem "rails", git: "https://github.com/rails/rails.git", branch: "main"
+  else
+    gem "rails", ENV["RAILS_VERSION"]
+  end
 end
 # rubocop:enable Bundler/DuplicatedGem