test: add unit test suite for backend API endpoints (#63)

backend/tests/conftest.py

@@ -0,0 +1,57 @@
+import os
+import sys
+import pytest
+from unittest.mock import MagicMock
+
+# Set test environment variables before any imports
+os.environ["GOOGLE_API_KEY"] = "test-key-for-testing"
+os.environ["RATE_LIMIT"] = "100/minute"
+os.environ["CORS_ALLOW_ORIGINS"] = "*"
+
+# Mock heavy dependencies that are not needed for API tests
+sys.modules["torch"] = MagicMock()
+sys.modules["google.cloud"] = MagicMock()
+sys.modules["google.cloud.aiplatform"] = MagicMock()
+sys.modules["google.cloud.bigquery"] = MagicMock()
+sys.modules["vertexai"] = MagicMock()
+sys.modules["vertexai.generative_models"] = MagicMock()
+sys.modules["google.generativeai"] = MagicMock()
+sys.modules["sentence_transformers"] = MagicMock()
+
+# Mock the retrieval module entirely
+mock_retriever = MagicMock()
+mock_retriever.Retriever = MagicMock()
+sys.modules["retrieval"] = mock_retriever
+
+# Mock the agents module with a fake assistant
+mock_assistant = MagicMock()
+mock_assistant.NeuroscienceAssistant = MagicMock
+
+
+class FakeAssistant:
+    """Fake assistant that returns predictable responses for testing."""
+
+    async def handle_chat(self, session_id="default", query="", reset=False):
+        return f"Test response for: {query}"
+
+    def reset_session(self, session_id):
+        pass
+
+
+mock_agents = MagicMock()
+mock_agents.NeuroscienceAssistant = FakeAssistant
+sys.modules["agents"] = mock_agents
+
+# Now we can safely import the app
+# Add backend to path so main.py can be found
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
+
+from main import app
+from fastapi.testclient import TestClient
+
+
+@pytest.fixture
+def client():
+    """Create a test client for the FastAPI app."""
+    with TestClient(app) as c:
+        yield c

backend/tests/test_health.py

@@ -0,0 +1,86 @@
+"""Tests for health check endpoints."""
+
+
+class TestRootEndpoint:
+
+    def test_root_returns_200(self, client):
+        response = client.get("/")
+        assert response.status_code == 200
+
+    def test_root_contains_message(self, client):
+        response = client.get("/")
+        data = response.json()
+        assert "message" in data
+        assert "running" in data["message"].lower()
+
+    def test_root_contains_version(self, client):
+        response = client.get("/")
+        data = response.json()
+        assert "version" in data
+        assert data["version"] == "2.0.0"
+
+
+class TestHealthEndpoint:
+
+    def test_health_returns_200(self, client):
+        response = client.get("/health")
+        assert response.status_code == 200
+
+    def test_health_status_is_healthy(self, client):
+        response = client.get("/health")
+        data = response.json()
+        assert data["status"] == "healthy"
+
+    def test_health_contains_timestamp(self, client):
+        response = client.get("/health")
+        data = response.json()
+        assert "timestamp" in data
+
+    def test_health_contains_service_name(self, client):
+        response = client.get("/health")
+        data = response.json()
+        assert data["service"] == "knowledge-space-agent-backend"
+
+    def test_health_contains_version(self, client):
+        response = client.get("/health")
+        data = response.json()
+        assert data["version"] == "2.0.0"
+
+
+class TestApiHealthEndpoint:
+
+    def test_api_health_returns_200(self, client):
+        response = client.get("/api/health")
+        assert response.status_code == 200
+
+    def test_api_health_status_is_healthy(self, client):
+        response = client.get("/api/health")
+        data = response.json()
+        assert data["status"] == "healthy"
+
+    def test_api_health_contains_components(self, client):
+        response = client.get("/api/health")
+        data = response.json()
+        assert "components" in data
+
+    def test_api_health_components_have_expected_keys(self, client):
+        response = client.get("/api/health")
+        components = response.json()["components"]
+        assert "vector_search" in components
+        assert "llm" in components
+        assert "keyword_search" in components
+
+    def test_api_health_keyword_search_always_enabled(self, client):
+        response = client.get("/api/health")
+        components = response.json()["components"]
+        assert components["keyword_search"] == "enabled"
+
+    def test_api_health_contains_timestamp(self, client):
+        response = client.get("/api/health")
+        data = response.json()
+        assert "timestamp" in data
+
+    def test_api_health_contains_version(self, client):
+        response = client.get("/api/health")
+        data = response.json()
+        assert data["version"] == "2.0.0"

backend/tests/test_query.py

@@ -0,0 +1,86 @@
+"""Tests for chat and session endpoints."""
+
+
+class TestChatEndpoint:
+
+    def test_chat_endpoint_exists(self, client):
+        response = client.post("/api/chat", json={"query": "test"})
+        assert response.status_code != 404
+
+    def test_chat_returns_response_field(self, client):
+        response = client.post("/api/chat", json={"query": "What is a neuron?"})
+        data = response.json()
+        assert "response" in data
+
+    def test_chat_returns_metadata(self, client):
+        response = client.post("/api/chat", json={"query": "test query"})
+        data = response.json()
+        assert "metadata" in data
+
+    def test_chat_metadata_contains_process_time(self, client):
+        response = client.post("/api/chat", json={"query": "test"})
+        if response.status_code == 200:
+            metadata = response.json().get("metadata", {})
+            assert "process_time" in metadata
+
+    def test_chat_metadata_contains_session_id(self, client):
+        response = client.post("/api/chat", json={"query": "test"})
+        if response.status_code == 200:
+            metadata = response.json().get("metadata", {})
+            assert "session_id" in metadata
+
+    def test_chat_with_custom_session_id(self, client):
+        response = client.post(
+            "/api/chat",
+            json={"query": "test", "session_id": "my-session-123"},
+        )
+        if response.status_code == 200:
+            metadata = response.json().get("metadata", {})
+            assert metadata.get("session_id") == "my-session-123"
+
+    def test_chat_missing_query_returns_422(self, client):
+        response = client.post("/api/chat", json={})
+        assert response.status_code == 422
+
+    def test_chat_get_method_not_allowed(self, client):
+        response = client.get("/api/chat")
+        assert response.status_code == 405
+
+
+class TestSessionResetEndpoint:
+
+    def test_reset_endpoint_exists(self, client):
+        response = client.post(
+            "/api/session/reset",
+            json={"session_id": "test-session"},
+        )
+        assert response.status_code != 404
+
+    def test_reset_returns_ok_status(self, client):
+        response = client.post(
+            "/api/session/reset",
+            json={"session_id": "test-session"},
+        )
+        if response.status_code == 200:
+            data = response.json()
+            assert data["status"] == "ok"
+
+    def test_reset_returns_session_id(self, client):
+        response = client.post(
+            "/api/session/reset",
+            json={"session_id": "my-session"},
+        )
+        if response.status_code == 200:
+            data = response.json()
+            assert data["session_id"] == "my-session"
+
+
+class TestUnknownRoutes:
+
+    def test_unknown_route_returns_404(self, client):
+        response = client.get("/this-does-not-exist")
+        assert response.status_code == 404
+
+    def test_unknown_api_route_returns_404(self, client):
+        response = client.get("/api/nonexistent")
+        assert response.status_code == 404

pyproject.toml

@@ -38,3 +38,10 @@ dev = [
     "flake8>=6.0.0",
     "mypy>=1.0.0",
 ]
+
+[tool.pytest.ini_options]
+testpaths = ["backend/tests"]
+python_files = ["test_*.py"]
+python_classes = ["Test*"]
+python_functions = ["test_*"]
+addopts = "-v --tb=short"