Attempt to run mutation tests in parallel for the most time-consuming context.

Author: dysk

.github/workflows/pricing.yml

@@ -36,20 +36,30 @@ jobs:
         continue-on-error: true
 
   mutate:
+    needs: test
     runs-on: ubuntu-24.04
     strategy:
       fail-fast: false
+      matrix:
+        total_nodes: [2]
+        node_index: [0, 1]
     env:
       WORKING_DIRECTORY: ecommerce/pricing
     steps:
       - uses: actions/checkout@v3
+
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ruby-3.3.7
           bundler-cache: true
           working-directory: ${{ env.WORKING_DIRECTORY }}
+
       - run: make mutate
+        env:
+          MUTANT_NODE_INDEX: ${{ matrix.node_index }}
+          MUTANT_TOTAL_NODES: ${{ matrix.total_nodes }}
         working-directory: ${{ env.WORKING_DIRECTORY }}
+
       - uses: 8398a7/action-slack@v3
         with:
           status: custom
@@ -58,7 +68,7 @@ jobs:
             {
               attachments: [{
                 color: '${{ job.status }}' === 'success' ? 'good' : '${{ job.status }}' === 'failure' ? 'danger' : 'warning',
-                text: `${process.env.AS_WORKFLOW}/${process.env.AS_JOB} ${{ job.status }} in ${process.env.AS_TOOK}\n${process.env.AS_COMMIT} in ${process.env.AS_REF}`,
+                text: `Workflow: ${process.env.AS_WORKFLOW}\nJob: ${process.env.AS_JOB} (Node ${{ matrix.node_index }}/${{ matrix.total_nodes }})\nStatus: ${{ job.status }} in ${process.env.AS_TOOK}\nCommit: ${process.env.AS_COMMIT} on ${process.env.AS_REF} by ${process.env.AS_AUTHOR}`,
               }]
             }
         env:

.github/workflows/rails_application.yml

@@ -48,9 +48,13 @@ jobs:
         continue-on-error: true
 
   mutate:
+    needs: test
     runs-on: ubuntu-24.04
     strategy:
       fail-fast: false
+      matrix:
+        total_nodes: [2]
+        node_index: [0, 1]
     env:
       WORKING_DIRECTORY: rails_application
     services:
@@ -64,16 +68,23 @@ jobs:
         options: --health-cmd pg_isready --health-interval 10s --health-timeout 5s --health-retries 5
     steps:
       - uses: actions/checkout@v3
+
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ruby-3.3.7
           bundler-cache: true
           working-directory: ${{ env.WORKING_DIRECTORY }}
+
       - name: Assets Precompile
         working-directory: ${{ env.WORKING_DIRECTORY }}
         run: bundle exec rails tailwindcss:build
+
       - run: make mutate
+        env:
+          MUTANT_NODE_INDEX: ${{ matrix.node_index }}
+          MUTANT_TOTAL_NODES: ${{ matrix.total_nodes }}
         working-directory: ${{ env.WORKING_DIRECTORY }}
+
       - uses: 8398a7/action-slack@v3
         with:
           status: custom
@@ -82,7 +93,7 @@ jobs:
             {
               attachments: [{
                 color: '${{ job.status }}' === 'success' ? 'good' : '${{ job.status }}' === 'failure' ? 'danger' : 'warning',
-                text: `${process.env.AS_WORKFLOW}/${process.env.AS_JOB} ${{ job.status }} in ${process.env.AS_TOOK}\n${process.env.AS_COMMIT} in ${process.env.AS_REF}`,
+                text: `Workflow: ${process.env.AS_WORKFLOW}\nJob: ${process.env.AS_JOB} (Node ${{ matrix.node_index }}/${{ matrix.total_nodes }})\nStatus: ${{ job.status }} in ${process.env.AS_TOOK}\nCommit: ${process.env.AS_COMMIT} on ${process.env.AS_REF} by ${process.env.AS_AUTHOR}`,
               }]
             }
         env:

ecommerce/pricing/Makefile

@@ -4,7 +4,25 @@ install:
 test:
 	@bundle exec ruby -e "require \"rake/rake_test_loader\"" test/*_test.rb
 
+MUTANT_TARGET_DIRS := lib
+
 mutate:
+ifeq ($(origin MUTANT_NODE_INDEX), environment)
+	@echo "Running mutation tests in parallel (Node $(MUTANT_NODE_INDEX)/$(MUTANT_TOTAL_NODES)) for pricing, using .mutant.yml"
+	@find $(MUTANT_TARGET_DIRS) -path ./vendor -prune -o -name '*.rb' -print | sed 's|^\./||' > .all_files.tmp
+	@awk "NR % $(MUTANT_TOTAL_NODES) == $(MUTANT_NODE_INDEX)" .all_files.tmp > .node_files.tmp
+	@SUBJECT_NAMES_CMD="cat .node_files.tmp | perl -pe 's|^lib/||; s|\\.rb$$||; s|/|::|g; s/\\b(\\w)/ucfirst(\$1)/ge'"
+	@SUBJECT_ARGS=$$($$SUBJECT_NAMES_CMD | tr '\\n' ' '); \
+	 if [ -z "$$SUBJECT_ARGS" ]; then \
+	   echo "No subjects derived for this node. Skipping."; \
+	 else \
+	   echo "Attempting to run mutant --fail-fast for derived subjects: $$SUBJECT_ARGS"; \
+	   RAILS_ENV=test bundle exec mutant --fail-fast run $$SUBJECT_ARGS; \
+	 fi
+	@rm -f .all_files.tmp .node_files.tmp
+else
+	@echo "Running mutation tests locally (using .mutant.yml)"
 	@RAILS_ENV=test bundle exec mutant run
+endif
 
 .PHONY: install test mutate

rails_application/Makefile

@@ -1,13 +1,12 @@
+MUTANT_TARGET_DIRS := app lib
+
 install: ## Installs dependencies, runs migrations, creates db & seeds if necessary
 	@bin/setup
 	@env RAILS_ENV=test bin/rails db:create
 
 dev:
 	@$(MAKE) -j 10 web css
 
-mutate: ## Run mutation tests
-	@env RAILS_ENV=test bundle exec mutant run
-
 test: ## Run unit tests
 	@bin/rails tailwindcss:build
 	@echo "Running unit tests"
@@ -16,6 +15,32 @@ test: ## Run unit tests
 help:
 	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'
 
+mutate: ## Run mutation tests
+ifeq ($(origin MUTANT_NODE_INDEX), environment)
+	@echo "Running mutation tests in parallel (Node $(MUTANT_NODE_INDEX)/$(MUTANT_TOTAL_NODES)) for rails_application"
+	@find $(MUTANT_TARGET_DIRS) -name '*.rb' \
+		-not -path '*/test/*' \
+		-not -path '*/spec/*' \
+		-not -path 'config/*' \
+		-not -path '*/initializers/*' \
+		-not -path 'db/*' \
+		-not -path 'vendor/*' \
+		-print > .all_files.tmp
+	@awk "NR % $(MUTANT_TOTAL_NODES) == $(MUTANT_NODE_INDEX)" .all_files.tmp > .node_files.tmp
+	@SUBJECT_NAMES_CMD="cat .node_files.tmp | perl -pe 's|^(app|lib)/||; s|\\.rb$$||; s|/|::|g; s/\\b(\\w)/ucfirst(\$1)/ge'"
+	@SUBJECT_ARGS=$$($$SUBJECT_NAMES_CMD | tr '\\n' ' '); \
+	 if [ -z "$$SUBJECT_ARGS" ]; then \
+	   echo "No subjects derived for this node. Skipping."; \
+	 else \
+	   echo "Attempting to run mutant --fail-fast for derived subjects: $$SUBJECT_ARGS"; \
+	   RAILS_ENV=test bundle exec mutant --fail-fast run $$SUBJECT_ARGS; \
+	 fi
+	@rm -f .all_files.tmp .node_files.tmp
+else
+	@echo "Running mutation tests locally for rails_application (mutant discovers subjects)"
+	@RAILS_ENV=test bundle exec mutant run
+endif
+
 .PHONY: help test db
 .DEFAULT_GOAL := help