Don't resolve default stt engine in assist pipelines (#91936)

* Don't resolve default stt engine in assist pipelines

* Apply suggestion from code review

* Add tests

* Tweak

* Add test

* Improve test coverage

homeassistant/components/assist_pipeline/pipeline.py

@@ -83,14 +83,16 @@ async def async_get_pipeline(
     if pipeline_id is None:
         # There's no preferred pipeline, construct a pipeline for the
         # configured language
+        stt_engine = stt.async_default_provider(hass)
+        stt_language = hass.config.language if stt_engine else None
         return await pipeline_data.pipeline_store.async_create_item(
             {
                 "conversation_engine": None,
                 "conversation_language": None,
                 "language": hass.config.language,
                 "name": hass.config.language,
-                "stt_engine": None,
-                "stt_language": None,
+                "stt_engine": stt_engine,
+                "stt_language": stt_language,
                 "tts_engine": None,
                 "tts_language": None,
                 "tts_voice": None,
@@ -261,22 +263,14 @@ class PipelineRun:
         """Prepare speech to text."""
         stt_provider: stt.SpeechToTextEntity | stt.Provider | None = None
 
-        if self.pipeline.stt_engine is not None:
-            # Try entity first
-            stt_provider = stt.async_get_speech_to_text_entity(
+        # pipeline.stt_engine can't be None or this function is not called
+        stt_provider = stt.async_get_speech_to_text_engine(
             self.hass,
-                self.pipeline.stt_engine,
+            self.pipeline.stt_engine,  # type: ignore[arg-type]
         )
 
         if stt_provider is None:
-            # Try legacy provider second
-            stt_provider = stt.async_get_provider(
-                self.hass,
-                self.pipeline.stt_engine,
-            )
-
-        if stt_provider is None:
-            engine = self.pipeline.stt_engine or "default"
+            engine = self.pipeline.stt_engine
             raise SpeechToTextError(
                 code="stt-provider-missing",
                 message=f"No speech to text provider for: {engine}",
@@ -580,11 +574,14 @@ class PipelineInput:
     async def validate(self) -> None:
         """Validate pipeline input against start stage."""
         if self.run.start_stage == PipelineStage.STT:
+            if self.run.pipeline.stt_engine is None:
+                raise PipelineRunValidationError(
+                    "the pipeline does not support speech to text"
+                )
             if self.stt_metadata is None:
                 raise PipelineRunValidationError(
                     "stt_metadata is required for speech to text"
                 )
-
             if self.stt_stream is None:
                 raise PipelineRunValidationError(
                     "stt_stream is required for speech to text"

homeassistant/components/stt/__init__.py

@@ -41,12 +41,14 @@ from .legacy import (
     Provider,
     SpeechMetadata,
     SpeechResult,
+    async_default_provider,
     async_get_provider,
     async_setup_legacy,
 )
 
 __all__ = [
     "async_get_provider",
+    "async_get_speech_to_text_engine",
     "async_get_speech_to_text_entity",
     "AudioBitRates",
     "AudioChannels",
@@ -64,6 +66,14 @@ __all__ = [
 _LOGGER = logging.getLogger(__name__)
 
 
+@callback
+def async_default_engine(hass: HomeAssistant) -> str | None:
+    """Return the domain or entity id of the default engine."""
+    return async_default_provider(hass) or next(
+        iter(hass.states.async_entity_ids(DOMAIN)), None
+    )
+
+
 @callback
 def async_get_speech_to_text_entity(
     hass: HomeAssistant, entity_id: str
@@ -74,6 +84,16 @@ def async_get_speech_to_text_entity(
     return component.get_entity(entity_id)
 
 
+@callback
+def async_get_speech_to_text_engine(
+    hass: HomeAssistant, engine_id: str
+) -> SpeechToTextEntity | Provider | None:
+    """Return stt entity or legacy provider."""
+    if entity := async_get_speech_to_text_entity(hass, engine_id):
+        return entity
+    return async_get_provider(hass, engine_id)
+
+
 @callback
 def async_get_speech_to_text_languages(hass: HomeAssistant) -> set[str]:
     """Return a set with the union of languages supported by stt engines."""

homeassistant/components/stt/legacy.py

@@ -27,6 +27,15 @@ from .const import (
 _LOGGER = logging.getLogger(__name__)
 
 
+@callback
+def async_default_provider(hass: HomeAssistant) -> str | None:
+    """Return the domain of the default provider."""
+    if "cloud" in hass.data[DATA_PROVIDERS]:
+        return "cloud"
+
+    return next(iter(hass.data[DATA_PROVIDERS]), None)
+
+
 @callback
 def async_get_provider(
     hass: HomeAssistant, domain: str | None = None
@@ -35,13 +44,8 @@ def async_get_provider(
     if domain:
         return hass.data[DATA_PROVIDERS].get(domain)
 
-    if not hass.data[DATA_PROVIDERS]:
-        return None
-
-    if "cloud" in hass.data[DATA_PROVIDERS]:
-        return hass.data[DATA_PROVIDERS]["cloud"]
-
-    return next(iter(hass.data[DATA_PROVIDERS].values()))
+    provider = async_default_provider(hass)
+    return hass.data[DATA_PROVIDERS][provider] if provider is not None else None
 
 
 @callback

tests/components/assist_pipeline/test_init.py

@@ -1,6 +1,7 @@
 """Test Voice Assistant init."""
 from dataclasses import asdict
 
+import pytest
 from syrupy.assertion import SnapshotAssertion
 
 from homeassistant.components import assist_pipeline, stt
@@ -184,3 +185,63 @@ async def test_pipeline_from_audio_stream_entity(
 
     assert processed == snapshot
     assert mock_stt_provider_entity.received == [b"part1", b"part2"]
+
+
+async def test_pipeline_from_audio_stream_no_stt(
+    hass: HomeAssistant,
+    hass_ws_client: WebSocketGenerator,
+    mock_stt_provider: MockSttProvider,
+    init_components,
+    snapshot: SnapshotAssertion,
+) -> None:
+    """Test creating a pipeline from an audio stream.
+
+    In this test, the pipeline does not support stt
+    """
+    client = await hass_ws_client(hass)
+
+    events = []
+
+    async def audio_data():
+        yield b"part1"
+        yield b"part2"
+        yield b""
+
+    # Create a pipeline without stt support
+    await client.send_json_auto_id(
+        {
+            "type": "assist_pipeline/pipeline/create",
+            "conversation_engine": "homeassistant",
+            "conversation_language": "en-US",
+            "language": "en",
+            "name": "test_name",
+            "stt_engine": None,
+            "stt_language": None,
+            "tts_engine": "test",
+            "tts_language": "en-AU",
+            "tts_voice": "Arnold Schwarzenegger",
+        }
+    )
+    msg = await client.receive_json()
+    assert msg["success"]
+    pipeline_id = msg["result"]["id"]
+
+    # Try to use the created pipeline
+    with pytest.raises(assist_pipeline.pipeline.PipelineRunValidationError):
+        await assist_pipeline.async_pipeline_from_audio_stream(
+            hass,
+            Context(),
+            events.append,
+            stt.SpeechMetadata(
+                language="en-UK",
+                format=stt.AudioFormats.WAV,
+                codec=stt.AudioCodecs.PCM,
+                bit_rate=stt.AudioBitRates.BITRATE_16,
+                sample_rate=stt.AudioSampleRates.SAMPLERATE_16000,
+                channel=stt.AudioChannels.CHANNEL_MONO,
+            ),
+            audio_data(),
+            pipeline_id=pipeline_id,
+        )
+
+    assert not events

tests/components/stt/test_init.py

@@ -18,7 +18,9 @@ from homeassistant.components.stt import (
     SpeechResult,
     SpeechResultState,
     SpeechToTextEntity,
+    async_default_engine,
     async_get_provider,
+    async_get_speech_to_text_engine,
 )
 from homeassistant.config_entries import ConfigEntry, ConfigEntryState, ConfigFlow
 from homeassistant.core import HomeAssistant, State
@@ -349,6 +351,9 @@ async def test_get_provider(
     await mock_setup(hass, tmp_path, mock_provider)
     assert mock_provider == async_get_provider(hass, TEST_DOMAIN)
 
+    # Test getting the default provider
+    assert mock_provider == async_get_provider(hass)
+
 
 async def test_config_entry_unload(
     hass: HomeAssistant, tmp_path: Path, mock_provider_entity: MockProviderEntity
@@ -444,3 +449,84 @@ async def test_ws_list_engines(
     assert msg["result"] == {
         "providers": [{"engine_id": engine_id, "supported_languages": ["de-CH", "de"]}]
     }
+
+
+async def test_default_engine_none(hass: HomeAssistant, tmp_path: Path) -> None:
+    """Test async_default_engine."""
+    assert await async_setup_component(hass, "stt", {"stt": {}})
+    await hass.async_block_till_done()
+
+    assert async_default_engine(hass) is None
+
+
+async def test_default_engine(hass: HomeAssistant, tmp_path: Path) -> None:
+    """Test async_default_engine."""
+    mock_stt_platform(
+        hass,
+        tmp_path,
+        TEST_DOMAIN,
+        async_get_engine=AsyncMock(return_value=mock_provider),
+    )
+    assert await async_setup_component(hass, "stt", {"stt": {"platform": TEST_DOMAIN}})
+    await hass.async_block_till_done()
+
+    assert async_default_engine(hass) == TEST_DOMAIN
+
+
+async def test_default_engine_entity(
+    hass: HomeAssistant, tmp_path: Path, mock_provider_entity: MockProviderEntity
+) -> None:
+    """Test async_default_engine."""
+    await mock_config_entry_setup(hass, tmp_path, mock_provider_entity)
+
+    assert async_default_engine(hass) == f"{DOMAIN}.{TEST_DOMAIN}"
+
+
+async def test_default_engine_prefer_cloud(hass: HomeAssistant, tmp_path: Path) -> None:
+    """Test async_default_engine."""
+    mock_stt_platform(
+        hass,
+        tmp_path,
+        TEST_DOMAIN,
+        async_get_engine=AsyncMock(return_value=mock_provider),
+    )
+    mock_stt_platform(
+        hass,
+        tmp_path,
+        "cloud",
+        async_get_engine=AsyncMock(return_value=mock_provider),
+    )
+    assert await async_setup_component(
+        hass, "stt", {"stt": [{"platform": TEST_DOMAIN}, {"platform": "cloud"}]}
+    )
+    await hass.async_block_till_done()
+
+    assert async_default_engine(hass) == "cloud"
+
+
+async def test_get_engine_legacy(
+    hass: HomeAssistant, tmp_path: Path, mock_provider: MockProvider
+) -> None:
+    """Test async_get_speech_to_text_engine."""
+    mock_stt_platform(
+        hass,
+        tmp_path,
+        TEST_DOMAIN,
+        async_get_engine=AsyncMock(return_value=mock_provider),
+    )
+    assert await async_setup_component(
+        hass, "stt", {"stt": [{"platform": TEST_DOMAIN}, {"platform": "cloud"}]}
+    )
+    await hass.async_block_till_done()
+
+    assert async_get_speech_to_text_engine(hass, "no_such_provider") is None
+    assert async_get_speech_to_text_engine(hass, "test") is mock_provider
+
+
+async def test_get_engine_entity(
+    hass: HomeAssistant, tmp_path: Path, mock_provider_entity: MockProviderEntity
+) -> None:
+    """Test async_get_speech_to_text_engine."""
+    await mock_config_entry_setup(hass, tmp_path, mock_provider_entity)
+
+    assert async_get_speech_to_text_engine(hass, "stt.test") is mock_provider_entity