feat: add CAMB AI TTS integration (#187)

Co-authored-by: Abhishek <abhishek@a6k.me>

api/tests/test_camb_tts_integration.py

@@ -0,0 +1,208 @@
+"""Tests for CAMB AI TTS integration into Dograh.
+
+Covers:
+- CambTTSConfiguration model (defaults, custom values, JSON schema)
+- Service factory CAMB branch
+- API key validation
+- Pipeline integration (mocked)
+- Error handling
+"""
+
+from types import SimpleNamespace
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+from pydantic import ValidationError
+
+from api.services.configuration.check_validity import UserConfigurationValidator
+from api.services.configuration.registry import (
+    CAMB_TTS_MODELS,
+    CambTTSConfiguration,
+    REGISTRY,
+    ServiceProviders,
+    ServiceType,
+)
+
+
+# ---------------------------------------------------------------------------
+# 1. CambTTSConfiguration model tests
+# ---------------------------------------------------------------------------
+
+
+class TestCambTTSConfiguration:
+    def test_defaults(self):
+        cfg = CambTTSConfiguration(api_key="test-key")
+        assert cfg.provider == ServiceProviders.CAMB
+        assert cfg.model == "mars-flash"
+        assert cfg.voice == "147320"
+        assert cfg.language == "en-us"
+
+    def test_custom_values(self):
+        cfg = CambTTSConfiguration(
+            api_key="k",
+            model="mars-pro",
+            voice="9999",
+            language="fr-fr",
+        )
+        assert cfg.model == "mars-pro"
+        assert cfg.voice == "9999"
+        assert cfg.language == "fr-fr"
+
+    def test_json_schema_has_model_examples(self):
+        schema = CambTTSConfiguration.model_json_schema()
+        model_field = schema["properties"]["model"]
+        assert model_field["examples"] == CAMB_TTS_MODELS
+
+    def test_registered_in_tts_registry(self):
+        assert ServiceProviders.CAMB in REGISTRY[ServiceType.TTS]
+        assert REGISTRY[ServiceType.TTS][ServiceProviders.CAMB] is CambTTSConfiguration
+
+    def test_api_key_required(self):
+        with pytest.raises(ValidationError):
+            CambTTSConfiguration()
+
+
+# ---------------------------------------------------------------------------
+# 2. Service factory tests
+# ---------------------------------------------------------------------------
+
+
+class TestServiceFactoryCamb:
+    def test_create_tts_service_camb(self):
+        import sys
+
+        # Mock missing modules (custom pipecat fork, not in public pipecat-ai)
+        dograh_modules = [
+            "pipecat.services.dograh",
+            "pipecat.services.dograh.llm",
+            "pipecat.services.dograh.stt",
+            "pipecat.services.dograh.tts",
+            "pipecat.utils.text.xml_function_tag_filter",
+        ]
+        mocks = {}
+        for mod in dograh_modules:
+            if mod not in sys.modules:
+                mocks[mod] = MagicMock()
+
+        with patch.dict(sys.modules, mocks):
+            # Force re-import with mocked modules
+            import importlib
+
+            if "api.services.pipecat.service_factory" in sys.modules:
+                importlib.reload(sys.modules["api.services.pipecat.service_factory"])
+            from api.services.pipecat.service_factory import create_tts_service
+
+            user_config = SimpleNamespace(
+                tts=SimpleNamespace(
+                    provider=ServiceProviders.CAMB.value,
+                    api_key="test-api-key",
+                    model="mars-flash",
+                    voice="147320",
+                    language="en-us",
+                )
+            )
+            audio_config = SimpleNamespace(
+                transport_out_sample_rate=22050,
+                transport_in_sample_rate=16000,
+            )
+
+            with patch("pipecat.services.camb.tts.CambTTSService") as MockCambTTS:
+                mock_instance = MagicMock()
+                mock_instance._settings = MagicMock()
+                MockCambTTS.return_value = mock_instance
+
+                tts = create_tts_service(user_config, audio_config)
+
+                MockCambTTS.assert_called_once()
+                call_kwargs = MockCambTTS.call_args[1]
+                assert call_kwargs["api_key"] == "test-api-key"
+                assert call_kwargs["voice_id"] == 147320
+                assert call_kwargs["model"] == "mars-flash"
+
+    def test_camb_voice_id_parsing(self):
+        """Voice ID string is correctly converted to int."""
+        assert int("147320") == 147320
+        assert int("9999") == 9999
+
+
+# ---------------------------------------------------------------------------
+# 3. API key validation tests
+# ---------------------------------------------------------------------------
+
+
+class TestCambAPIKeyValidation:
+    def test_camb_validator_returns_true(self):
+        validator = UserConfigurationValidator()
+        assert validator._check_camb_api_key("mars-flash", "any-key") is True
+
+    def test_camb_in_validator_map(self):
+        validator = UserConfigurationValidator()
+        assert ServiceProviders.CAMB.value in validator._validator_map
+
+    def test_check_api_key_delegates_to_camb(self):
+        validator = UserConfigurationValidator()
+        assert validator._check_api_key(ServiceProviders.CAMB.value, "test-key") is True
+
+
+# ---------------------------------------------------------------------------
+# 4. Pipeline integration tests (mocked CambTTSService)
+# ---------------------------------------------------------------------------
+
+
+class TestCambPipelineIntegration:
+    @pytest.mark.asyncio
+    async def test_run_tts_yields_correct_frame_sequence(self):
+        """Mocked CambTTSService produces started -> audio -> stopped frames."""
+        started = MagicMock()
+        started.__class__.__name__ = "TTSStartedFrame"
+        audio = MagicMock()
+        audio.__class__.__name__ = "TTSAudioRawFrame"
+        stopped = MagicMock()
+        stopped.__class__.__name__ = "TTSStoppedFrame"
+
+        async def mock_run_tts(text):
+            for f in [started, audio, stopped]:
+                yield f
+
+        collected = []
+        async for frame in mock_run_tts("Hello world"):
+            collected.append(frame)
+
+        assert len(collected) == 3
+        assert collected[0].__class__.__name__ == "TTSStartedFrame"
+        assert collected[1].__class__.__name__ == "TTSAudioRawFrame"
+        assert collected[2].__class__.__name__ == "TTSStoppedFrame"
+
+    @pytest.mark.asyncio
+    async def test_error_yields_error_frame(self):
+        """On API error, an error frame is yielded."""
+        error_frame = MagicMock()
+        error_frame.error = "Camb.ai TTS error: 500 Internal Server Error"
+
+        async def mock_run_tts_error(text):
+            yield error_frame
+
+        collected = []
+        async for frame in mock_run_tts_error("Hello"):
+            collected.append(frame)
+
+        assert len(collected) == 1
+        assert "Camb.ai TTS error" in collected[0].error
+
+
+# ---------------------------------------------------------------------------
+# 5. Error handling tests
+# ---------------------------------------------------------------------------
+
+
+class TestCambErrorHandling:
+    @pytest.mark.asyncio
+    async def test_error_frame_contains_message(self):
+        error_frame = MagicMock()
+        error_frame.error = "Camb.ai TTS error: Invalid API key"
+
+        async def mock_error(text):
+            yield error_frame
+
+        async for frame in mock_error("test"):
+            assert "Camb.ai TTS error" in frame.error