CI: separate build and test env for gem

Signed-off-by: Daijiro Fukuda <fukuda@clear-code.com>

Author: daipom

.github/workflows/main.yml

@@ -12,7 +12,7 @@ jobs:
       fail-fast: false
       matrix:
         ruby: ['3.4', '3.3', '3.2']
-        os: ['ubuntu-latest', 'macos-latest', 'windows-latest']
+        os: [ubuntu-latest, macos-latest, windows-latest]
         include:
           - os: ubuntu-latest
             ruby: 2.7.1
@@ -22,37 +22,55 @@ jobs:
     name: Test with Ruby ${{ matrix.ruby }} on ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
-      - name: Set up Ruby
-        uses: ruby/setup-ruby@v1
+      - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
           bundler-cache: true
       - name: Test
         run: bundle exec rake
 
-  gem:
+  build:
+    runs-on: ubuntu-latest
+    name: Build gem
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: '3.4'
+          bundler-cache: true
+      - name: Build
+        run: bundler exec rake build
+      - uses: actions/upload-artifact@v4
+        with:
+          name: gem
+          path: pkg/*.gem
+
+  gem-test:
+    needs: build
     strategy:
       fail-fast: false
       matrix:
         ruby: ['3.4', '3.3', '3.2', '2.7.1']
         # macOS is excluded because of the difficulty in assuming a macOS shell behavior.
-        os: ['ubuntu-latest', 'windows-latest']
+        os: [ubuntu-latest, windows-latest]
         include:
           - os: ubuntu-latest
             shell: bash
           - os: windows-latest
             shell: cmd
     runs-on: ${{ matrix.os }}
-    name: Gem with Ruby ${{ matrix.ruby }} on ${{ matrix.os }}
+    name: Gem test with Ruby ${{ matrix.ruby }} on ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
-      - name: Set up Ruby
-        uses: ruby/setup-ruby@v1
+      - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
-          bundler-cache: true
-      - name: Install
-        run: rake install
+      - uses: actions/download-artifact@v4
+        with:
+          name: gem
+          path: pkg
+      - name: Install gem
+        run: gem install pkg/*
       - name: Test command (bash)
         if: ${{ matrix.shell == 'bash' }}
         run: test/script/command-test.bash