ci: Run ReJest self-tests and verify CI catches failing tests

Author: tjzel

.github/workflows/runtime-tests-ios.yml

@@ -93,3 +93,22 @@ jobs:
           || node scripts/runtime-tests-server.js --launch --library worklets
           --configuration "$CONFIGURATION" --skip-build --connect-timeout 900 --idle-timeout 900
           ${{ inputs.bundleMode && '--include "bundle mode core"' || '' }}
+
+      - name: Run ReJest self-tests (reuses the build, retries once)
+        working-directory: ${{ env.WORKING_DIRECTORY }}
+        run: >-
+          node scripts/runtime-tests-server.js --launch --library self-tests
+          --configuration "$CONFIGURATION" --skip-build --connect-timeout 900 --idle-timeout 900
+          || node scripts/runtime-tests-server.js --launch --library self-tests
+          --configuration "$CONFIGURATION" --skip-build --connect-timeout 900 --idle-timeout 900
+
+      # The "intentional failures" suite only contains failing tests; the runner
+      # exiting zero here would mean CI cannot catch real failures.
+      - name: Verify CI catches failing tests
+        working-directory: ${{ env.WORKING_DIRECTORY }}
+        run: >-
+          if node scripts/runtime-tests-server.js --launch --library self-tests
+          --configuration "$CONFIGURATION" --skip-build --connect-timeout 900 --idle-timeout 900
+          --only "intentional failures";
+          then echo "A failing suite did not fail the runner" && exit 1;
+          else echo "Failing tests correctly failed the runner"; fi