Add support for Piper TTS

tests/test_piper_tts.py

@@ -0,0 +1,101 @@
+"""Tests for PiperTTSService."""
+
+import asyncio
+
+import pytest
+from aiohttp import web
+
+from pipecat.frames.frames import (
+    ErrorFrame,
+    TTSAudioRawFrame,
+    TTSStartedFrame,
+    TTSStoppedFrame,
+)
+from pipecat.services.piper import PiperTTSService
+
+
+@pytest.mark.asyncio
+async def test_run_piper_tts_success(aiohttp_client):
+    """Test successful TTS generation with chunked audio data.
+
+    Checks frames for TTSStartedFrame -> TTSAudioRawFrame -> TTSStoppedFrame.
+    """
+
+    async def handler(request):
+        # The service expects a /?text= param
+        # Here we're just returning dummy chunked bytes to simulate an audio response
+        text_query = request.rel_url.query.get("text", "")
+        print(f"Mock server received text param: {text_query}")
+
+        # Prepare a StreamResponse with chunked data
+        resp = web.StreamResponse(
+            status=200,
+            reason="OK",
+            headers={"Content-Type": "audio/raw"},
+        )
+        await resp.prepare(request)
+
+        # Write out some chunked byte data
+        # In reality, you’d return WAV data or similar
+        data_chunk_1 = b"\x00\x01\x02\x03" * 12000  # 48000 bytes
+        data_chunk_2 = b"\x04\x05\x06\x07" * 6000  # another chunk
+        await resp.write(data_chunk_1)
+        await asyncio.sleep(0.01)  # simulate async chunk delay
+        await resp.write(data_chunk_2)
+        await resp.write_eof()
+
+        return resp
+
+    # Create an aiohttp test server
+    app = web.Application()
+    app.router.add_get("/", handler)
+    client = await aiohttp_client(app)
+
+    # Remove trailing slash if present in the test URL
+    base_url = str(client.make_url("")).rstrip("/")
+
+    # Instantiate PiperTTSService with our mock server
+    tts_service = PiperTTSService(base_url=base_url)
+
+    # Collect frames from the generator
+    frames = []
+    async for frame in tts_service.run_tts("Hello world."):
+        frames.append(frame)
+
+    # Ensure we received frames in the expected order/types
+    assert len(frames) >= 3, "Expecting at least TTSStartedFrame, TTSAudioRawFrame, TTSStoppedFrame"
+    assert isinstance(frames[0], TTSStartedFrame), "First frame must be TTSStartedFrame"
+    assert isinstance(frames[-1], TTSStoppedFrame), "Last frame must be TTSStoppedFrame"
+
+    # Check we have at least one TTSAudioRawFrame
+    audio_frames = [f for f in frames if isinstance(f, TTSAudioRawFrame)]
+    assert len(audio_frames) > 0, "Should have received at least one TTSAudioRawFrame"
+    for a_frame in audio_frames:
+        assert a_frame.sample_rate == 24000, "Sample rate should match the default (24000)"
+
+
+@pytest.mark.asyncio
+async def test_run_piper_tts_error(aiohttp_client):
+    """Test how the service handles a non-200 response from the server.
+
+    Expects an ErrorFrame to be returned.
+    """
+
+    async def handler(_request):
+        # Return an error status for any request
+        return web.Response(status=404, text="Not found")
+
+    app = web.Application()
+    app.router.add_get("/", handler)
+    client = await aiohttp_client(app)
+    base_url = str(client.make_url("")).rstrip("/")
+
+    tts_service = PiperTTSService(base_url=base_url)
+
+    frames = []
+    async for frame in tts_service.run_tts("Error case."):
+        frames.append(frame)
+
+    assert len(frames) == 1, "Should only receive a single ErrorFrame"
+    assert isinstance(frames[0], ErrorFrame), "Must receive an ErrorFrame for 404"
+    assert "status: 404" in frames[0].error, "ErrorFrame should contain details about the 404"