[claude] refactor: break up cascade.py complete() (#1185) (#1190)

tests/infrastructure/test_router_cascade.py

@@ -1376,3 +1376,141 @@ class TestIsProviderAvailable:
         result = router._is_provider_available(provider)
         assert result is True
         assert provider.circuit_state == CircuitState.HALF_OPEN
+
+
+@pytest.mark.unit
+class TestFilterProviders:
+    """Test _filter_providers helper extracted from complete()."""
+
+    def _router(self) -> CascadeRouter:
+        router = CascadeRouter(config_path=Path("/nonexistent"))
+        router.providers = [
+            Provider(
+                name="anthropic-p",
+                type="anthropic",
+                enabled=True,
+                priority=1,
+                api_key="key",
+                tier="frontier",
+            ),
+            Provider(
+                name="ollama-p",
+                type="ollama",
+                enabled=True,
+                priority=2,
+                tier="local",
+            ),
+        ]
+        return router
+
+    def test_no_tier_returns_all_providers(self):
+        router = self._router()
+        result = router._filter_providers(None)
+        assert result is router.providers
+
+    def test_frontier_required_returns_only_anthropic(self):
+        router = self._router()
+        result = router._filter_providers("frontier_required")
+        assert len(result) == 1
+        assert result[0].type == "anthropic"
+
+    def test_frontier_required_no_anthropic_raises(self):
+        router = CascadeRouter(config_path=Path("/nonexistent"))
+        router.providers = [
+            Provider(name="ollama-p", type="ollama", enabled=True, priority=1)
+        ]
+        with pytest.raises(RuntimeError, match="No Anthropic provider configured"):
+            router._filter_providers("frontier_required")
+
+    def test_named_tier_filters_by_tier(self):
+        router = self._router()
+        result = router._filter_providers("local")
+        assert len(result) == 1
+        assert result[0].name == "ollama-p"
+
+    def test_named_tier_not_found_raises(self):
+        router = self._router()
+        with pytest.raises(RuntimeError, match="No providers found for tier"):
+            router._filter_providers("nonexistent")
+
+
+@pytest.mark.unit
+@pytest.mark.asyncio
+class TestTrySingleProvider:
+    """Test _try_single_provider helper extracted from complete()."""
+
+    def _router(self) -> CascadeRouter:
+        return CascadeRouter(config_path=Path("/nonexistent"))
+
+    def _provider(self, name: str = "test", ptype: str = "ollama") -> Provider:
+        return Provider(
+            name=name,
+            type=ptype,
+            enabled=True,
+            priority=1,
+            models=[{"name": "llama3.2", "default": True}],
+        )
+
+    async def test_unavailable_provider_returns_none(self):
+        router = self._router()
+        provider = self._provider()
+        provider.enabled = False
+        errors: list[str] = []
+        result = await router._try_single_provider(
+            provider, [], None, 0.7, None, ContentType.TEXT, errors
+        )
+        assert result is None
+        assert errors == []
+
+    async def test_quota_blocked_cloud_provider_returns_none(self):
+        router = self._router()
+        provider = self._provider(ptype="anthropic")
+        errors: list[str] = []
+        with patch("infrastructure.router.cascade._quota_monitor") as mock_qm:
+            mock_qm.select_model.return_value = "qwen3:14b"  # non-cloud → ACTIVE tier
+            mock_qm.check.return_value = None
+            result = await router._try_single_provider(
+                provider, [], None, 0.7, None, ContentType.TEXT, errors
+            )
+        assert result is None
+        assert errors == []
+
+    async def test_success_returns_result_dict(self):
+        router = self._router()
+        provider = self._provider()
+        errors: list[str] = []
+        with patch.object(router, "_call_ollama") as mock_call:
+            mock_call.return_value = {"content": "hi", "model": "llama3.2"}
+            result = await router._try_single_provider(
+                provider,
+                [{"role": "user", "content": "hi"}],
+                None,
+                0.7,
+                None,
+                ContentType.TEXT,
+                errors,
+            )
+        assert result is not None
+        assert result["content"] == "hi"
+        assert result["provider"] == "test"
+        assert errors == []
+
+    async def test_failure_appends_error_and_returns_none(self):
+        router = self._router()
+        provider = self._provider()
+        errors: list[str] = []
+        with patch.object(router, "_call_ollama") as mock_call:
+            mock_call.side_effect = RuntimeError("boom")
+            result = await router._try_single_provider(
+                provider,
+                [{"role": "user", "content": "hi"}],
+                None,
+                0.7,
+                None,
+                ContentType.TEXT,
+                errors,
+            )
+        assert result is None
+        assert len(errors) == 1
+        assert "boom" in errors[0]
+        assert provider.metrics.failed_requests == 1