Avoid trying to import platforms that do not exist (#112028)

* Avoid trying to import platforms that do not exist

* adjust

* fixes

* cleanup

* cleanup

* cleanup

* Apply suggestions from code review

* docs

* fixes

* fixes

* comment

* coverage

* coverage

* coverage

* Switch config to use async_get_component

This was another path where integrations that were marked to load in the executor
would be loaded in the loop

* Switch config to use async_get_component/async_get_platform

This was another path where integrations that were marked to load in the executor
would be loaded in the loop

* merge

* refactor

* refactor

* coverage

* preen

* preen

tests/testing_config/custom_components/test_integration_platform/__init__.py

@@ -0,0 +1,9 @@
+"""Provide a mock package component."""
+from .const import TEST  # noqa: F401
+
+DOMAIN = "test_integration_platform"
+
+
+async def async_setup(hass, config):
+    """Mock a successful setup."""
+    return True

tests/testing_config/custom_components/test_integration_platform/config_flow.py

@@ -0,0 +1,7 @@
+"""Config flow."""
+
+from homeassistant.core import HomeAssistant
+
+
+async def _async_has_devices(hass: HomeAssistant) -> bool:
+    return True

tests/testing_config/custom_components/test_integration_platform/const.py

@@ -0,0 +1,2 @@
+"""Constants for test_package custom component."""
+TEST = 5

tests/testing_config/custom_components/test_integration_platform/group.py

@@ -0,0 +1,3 @@
+"""Group."""
+
+MAGIC = 1

tests/testing_config/custom_components/test_integration_platform/manifest.json

@@ -0,0 +1,11 @@
+{
+  "domain": "test_integration_platform",
+  "name": "Test Integration Platform",
+  "documentation": "http://test-package.io",
+  "requirements": [],
+  "dependencies": [],
+  "codeowners": [],
+  "config_flow": true,
+  "import_executor": true,
+  "version": "1.2.3"
+}