flatten

.github/workflows/ci.yml

@@ -537,12 +537,12 @@ jobs:
         if: always()
 
   test-build-components-split:
-    name: Test components batch (${{ join(matrix.components, ' ') }})
+    name: Test components batch (${{ matrix.components }})
     runs-on: ubuntu-24.04
     needs:
       - common
       - determine-jobs
-    if: github.event_name == 'pull_request' && needs.determine-jobs.outputs.component-test-batches != '[]'
+    if: github.event_name == 'pull_request' && fromJSON(needs.determine-jobs.outputs.component-test-count) > 0
     strategy:
       fail-fast: false
       max-parallel: ${{ (startsWith(github.base_ref, 'beta') || startsWith(github.base_ref, 'release')) && 8 || 4 }}
@@ -555,7 +555,7 @@ jobs:
           df -h
 
       - name: List components
-        run: echo ${{ join(matrix.components, ' ') }}
+        run: echo ${{ matrix.components }}
 
       - name: Cache apt packages
         uses: awalsh128/cache-apt-pkgs-action@acb598e5ddbc6f68a970c5da0688d2f3a9f04d05 # v1.5.3

script/determine-jobs.py

@@ -695,15 +695,17 @@ def main() -> None:
 
     # Split components into batches for CI testing
     # This intelligently groups components with similar bus configurations
-    component_test_batches: list[list[str]]
+    component_test_batches: list[str]
     if changed_components_with_tests:
         tests_dir = Path(root_path) / ESPHOME_TESTS_COMPONENTS_PATH
-        component_test_batches, _ = create_intelligent_batches(
+        batches, _ = create_intelligent_batches(
             components=changed_components_with_tests,
             tests_dir=tests_dir,
             batch_size=COMPONENT_TEST_BATCH_SIZE,
             directly_changed=directly_changed_with_tests,
         )
+        # Convert batches to space-separated strings for CI matrix
+        component_test_batches = [" ".join(batch) for batch in batches]
     else:
         component_test_batches = []