docs(django): clarify exception test limitations

Exception tests verify 500 responses but not actual PostHog capture. Exception capture requires process_exception() method from PR #350.

Without process_exception(), Django converts view exceptions to responses before they propagate through the middleware context manager, so they're not captured to PostHog even though 500 is still returned.

Author: webjunkie

test_project_django5/test_middleware.py

@@ -133,31 +133,42 @@ async def test_async_exception_capture():
     """
     Test that middleware captures exceptions from async views.
 
-    The middleware should capture the exception and send it to PostHog.
+    IMPORTANT: This test verifies that exceptions raise 500 errors, but it doesn't
+    verify that PostHog actually captures them. The exception capture fix (PR #350)
+    adds a process_exception() method that Django calls to capture view exceptions.
+
+    Without process_exception(), Django converts view exceptions to responses
+    before they propagate through the middleware context manager, so they're not
+    captured to PostHog even though they still return 500 to the client.
+
+    To properly test exception capture, you'd need to mock posthog.capture_exception
+    and verify it's called. That's tested in PR #350.
     """
     app = get_asgi_application()
     async with AsyncClient(transport=ASGITransport(app=app), base_url="http://testserver") as ac:
         response = await ac.get("/test/async-exception")
 
     # Django returns 500 for unhandled exceptions
     assert response.status_code == 500
-    print("✓ Async exception capture test passed (exception raised as expected)")
+    print("✓ Async exception raises 500 (capture requires process_exception from PR #350)")
 
 
 @pytest.mark.asyncio
 async def test_sync_exception_capture():
     """
-    Test that middleware captures exceptions from sync views.
+    Test that middleware handles exceptions from sync views.
 
-    The middleware should capture the exception and send it to PostHog.
+    IMPORTANT: Same as test_async_exception_capture - this verifies 500 response
+    but not actual PostHog capture. Exception capture requires process_exception()
+    method from PR #350.
     """
     app = get_asgi_application()
     async with AsyncClient(transport=ASGITransport(app=app), base_url="http://testserver") as ac:
         response = await ac.get("/test/sync-exception")
 
     # Django returns 500 for unhandled exceptions
     assert response.status_code == 500
-    print("✓ Sync exception capture test passed (exception raised as expected)")
+    print("✓ Sync exception raises 500 (capture requires process_exception from PR #350)")
 
 
 if __name__ == "__main__":