Use the preferred assist pipeline if none was specified (#91611)

* Use the preferred assist pipeline if none was specified

* Add test

homeassistant/components/assist_pipeline/pipeline.py

@@ -58,10 +58,13 @@ async def async_get_pipeline(
     """Get a pipeline by id or create one for a language."""
     pipeline_data: PipelineData = hass.data[DOMAIN]
 
-    if pipeline_id is not None:
+    if pipeline_id is None:
-        return pipeline_data.pipeline_store.data.get(pipeline_id)
+        # A pipeline was not specified, use the preferred one
+        pipeline_id = pipeline_data.pipeline_store.async_get_preferred_item()
 
-    # Construct a pipeline for the required/configured language
+    if pipeline_id is None:
+        # There's no preferred pipeline, construct a pipeline for the
+        # required/configured language
         language = language or hass.config.language
         return await pipeline_data.pipeline_store.async_create_item(
             {
@@ -73,6 +76,8 @@ async def async_get_pipeline(
             }
         )
 
+    return pipeline_data.pipeline_store.data.get(pipeline_id)
+
 
 class PipelineEventType(StrEnum):
     """Event types emitted during a pipeline run."""

tests/components/assist_pipeline/test_pipeline.py

@@ -7,6 +7,7 @@ from homeassistant.components.assist_pipeline.pipeline import (
     STORAGE_VERSION,
     PipelineData,
     PipelineStorageCollection,
+    async_get_pipeline,
 )
 from homeassistant.core import HomeAssistant
 from homeassistant.helpers.storage import Store
@@ -109,3 +110,24 @@ async def test_loading_datasets_from_storage(
     store = pipeline_data.pipeline_store
     assert len(store.data) == 3
     assert store.async_get_preferred_item() == "01GX8ZWBAQYWNB1XV3EXEZ75DY"
+
+
+async def test_get_pipeline(hass: HomeAssistant) -> None:
+    """Test async_get_pipeline."""
+    assert await async_setup_component(hass, "assist_pipeline", {})
+
+    pipeline_data: PipelineData = hass.data[DOMAIN]
+    store = pipeline_data.pipeline_store
+    assert len(store.data) == 0
+
+    # Test a pipeline is created
+    pipeline = await async_get_pipeline(hass, None)
+    assert len(store.data) == 1
+
+    # Test we get the same pipeline again
+    assert pipeline is await async_get_pipeline(hass, None)
+    assert len(store.data) == 1
+
+    # Test getting a specific pipeline
+    assert pipeline is await async_get_pipeline(hass, pipeline.id)
+    assert len(store.data) == 1