Test with Ruby 3.2 and below

.github/workflows/main.yml

@@ -1,27 +1,22 @@
 name: Ruby
 
-on:
-  push:
-    branches:
-      - main
-
-  pull_request:
+on: [push, pull_request]
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
     name: Ruby ${{ matrix.ruby }}
     strategy:
       matrix:
-        ruby:
-          - '3.2.2'
+        os: [ubuntu-latest, macos-latest]
+        ruby: [2.7, 3.0, 3.1, 3.2, head]
 
     steps:
-    - uses: actions/checkout@v3
-    - name: Set up Ruby
-      uses: ruby/setup-ruby@v1
-      with:
-        ruby-version: ${{ matrix.ruby }}
-        bundler-cache: true
-    - name: Run the default task
-      run: bundle exec rake
+      - uses: actions/checkout@v3
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+          bundler-cache: true
+      - name: Run the default task
+        run: bundle exec rake