Add default config if not there (#43321)

Co-authored-by: Bram Kragten <mail@bramkragten.nl>

tests/components/blueprint/test_default_blueprints.py

@@ -0,0 +1,28 @@
+"""Test default blueprints."""
+import importlib
+import logging
+import pathlib
+
+import pytest
+
+from homeassistant.components.blueprint import models
+from homeassistant.components.blueprint.const import BLUEPRINT_FOLDER
+from homeassistant.util import yaml
+
+DOMAINS = ["automation"]
+LOGGER = logging.getLogger(__name__)
+
+
+@pytest.mark.parametrize("domain", DOMAINS)
+def test_default_blueprints(domain: str):
+    """Validate a folder of blueprints."""
+    integration = importlib.import_module(f"homeassistant.components.{domain}")
+    blueprint_folder = pathlib.Path(integration.__file__).parent / BLUEPRINT_FOLDER
+    items = list(blueprint_folder.glob("*"))
+    assert len(items) > 0, "Folder cannot be empty"
+
+    for fil in items:
+        LOGGER.info("Processing %s", fil)
+        assert fil.name.endswith(".yaml")
+        data = yaml.load_yaml(fil)
+        models.Blueprint(data, expected_domain=domain)