Generate the expected matrix for GHA

.github/workflows/test-callable.yml

@@ -23,7 +23,7 @@ jobs:
       - name: Compute matrix
         id: matrix
         run: |
-          echo "matrix=$(ruby matrix.rb)" >> $GITHUB_OUTPUT
+          echo "matrix=$(ruby matrix.rb ${{ inputs.engine_name }} ${{ inputs.engine_version }})" >> $GITHUB_OUTPUT
 
   test:
     runs-on: ubuntu-latest

matrix.rb

@@ -8,7 +8,7 @@
   '3.1' => ['9.4'],
 }
 
-matrix = map.each_with_object({}) do |(spec, appraisals), h|
+definitions = map.each_with_object({}) do |(spec, appraisals), h|
   h[spec] = appraisals.each_with_object({}) do |(group, rubies), h2|
     ruby = rubies.scan(/✅ (\S+)/).flatten
 
@@ -25,6 +25,29 @@
 end
 
 # Rails 4.x is not supported on JRuby 9.2 (which is RUBY_VERSION 2.5)
-matrix.each { |_, appraisals| appraisals.each { |appraisal, engines| appraisal =~ /^rails4/ && engines.key?('jruby') && engines['jruby'].delete('9.2') } }
+definitions.each { |_, appraisals| appraisals.each { |appraisal, engines| appraisal =~ /^rails4/ && engines.key?('jruby') && engines['jruby'].delete('9.2') } }
+
+matrix = definitions.each_with_object([]) do |(spec, appraisals), a|
+  appraisals.each do |appraisal, engines|
+    engines.each do |engine, versions|
+      versions.each do |version|
+        a << {
+          spec: {
+            task: spec,
+            appraisal: appraisal,
+          },
+          engine: {
+            name: engine,
+            version: version
+          }
+        }
+      end
+    end
+  end
+end
+
+if (for_engine = ARGV[0]) && (for_version = ARGV[1])
+  matrix.select! { |e| e[:engine][:name] == for_engine && e[:engine][:version] == for_version }
+end
 
-puts(JSON.dump(matrix))
+puts(JSON.dump({ include: matrix }))