Fix test coverage.

Author: ioquatix

.github/workflows/test-coverage.yaml

@@ -11,17 +11,24 @@ env:
 
 jobs:
   test:
-    name: ${{matrix.ruby}} on ${{matrix.os}}
+    name: ${{matrix.ruby}} on ${{matrix.os}} ${{matrix.gemfile}}
     runs-on: ${{matrix.os}}-latest
+    env:
+      BUNDLE_GEMFILE: ${{matrix.gemfile}}
 
     strategy:
       matrix:
         os:
           - ubuntu
-          - macos
-        
+
         ruby:
           - "3.4"
+        
+        gemfile:
+          - gems/rack-v1.rb
+          - gems/rack-v2.rb
+          - gems/rack-v30.rb
+          - gems/rack-v31.rb
 
     steps:
     - uses: actions/checkout@v4
@@ -38,7 +45,7 @@ jobs:
       with:
         include-hidden-files: true
         if-no-files-found: error
-        name: coverage-${{matrix.os}}-${{matrix.ruby}}
+        name: coverage-${{matrix.os}}-${{matrix.ruby}}-${{matrix.gemfile}}
         path: .covered.db
 
   validate: