Don't bubble up Application User errors

Author: bowenwr

examples/chem-sync-local-flask/local_app/benchling_app/handler.py

@@ -1,5 +1,6 @@
 from typing import Any
 
+from benchling_sdk.apps.status.errors import AppUserFacingError
 from benchling_sdk.models.webhooks.v0 import (
     CanvasInitializeWebhookV0,
     CanvasInteractionWebhookV0,
@@ -25,11 +26,17 @@ def handle_webhook(webhook_dict: dict[str, Any]) -> None:
     # Could also choose to route on webhook.message.type
     # Note: if your manifest specifies more than one item in `features`,
     # then `webhook.message.feature_id` may also need to be part of your routing logic
-    if isinstance(webhook.message, CanvasInitializeWebhookV0):
-        render_search_canvas(app, webhook.message)
-    elif isinstance(webhook.message, CanvasInteractionWebhookV0):
-        route_interaction_webhook(app, webhook.message)
-    else:
-        # Should only happen if the app's manifest requests webhooks that aren't handled in its code paths
-        raise UnsupportedWebhookError(f"Received an unsupported webhook type: {webhook}")
-    logger.debug("Successfully completed request for webhook: %s", webhook_dict)
+    try:
+        if isinstance(webhook.message, CanvasInitializeWebhookV0):
+            render_search_canvas(app, webhook.message)
+        elif isinstance(webhook.message, CanvasInteractionWebhookV0):
+            route_interaction_webhook(app, webhook.message)
+        else:
+            # Should only happen if the app's manifest requests webhooks that aren't handled in its code paths
+            raise UnsupportedWebhookError(f"Received an unsupported webhook type: {webhook}")  # noqa: TRY301
+        logger.debug("Successfully completed request for webhook: %s", webhook_dict)
+    # We want errors shown to the user to end control flow, but we don't want them to propagate
+    # and show as errors in our logs.
+    # For this example, Flask error handler won't intercept this since we're within a thread
+    except AppUserFacingError as e:
+        logger.debug("Exiting with client error: %s", e)

examples/chem-sync-local-flask/tests/unit/local_app/benchling_app/test_handler.py

@@ -1,8 +1,9 @@
 from pathlib import Path
-from unittest.mock import MagicMock, patch
+from unittest.mock import MagicMock, call, patch
 
 import pytest
 from benchling_sdk.apps.framework import App
+from benchling_sdk.apps.status.errors import AppUserFacingError
 
 from local_app.benchling_app.handler import UnsupportedWebhookError, handle_webhook
 from tests.helpers import load_webhook_json
@@ -40,3 +41,21 @@ def test_handle_webhook_unsupported(self, mock_init_app_from_webhook) -> None:
         mock_init_app_from_webhook.return_value = mock_app
         with pytest.raises(UnsupportedWebhookError):
             handle_webhook(webhook.to_dict())
+
+    @patch("local_app.benchling_app.handler.logger")
+    @patch("local_app.benchling_app.handler.render_search_canvas")
+    @patch("local_app.benchling_app.handler.init_app_from_webhook")
+    def test_handle_webhook_user_error(self,
+                                       mock_init_app_from_webhook,
+                                       mock_render_search_canvas,
+                                       mock_logger) -> None:
+        webhook = load_webhook_json(_TEST_FILES_PATH / "canvas_initialize_webhook.json")
+        mock_app = MagicMock(App)
+        mock_init_app_from_webhook.return_value = mock_app
+        mock_error = AppUserFacingError("Client error")
+        mock_render_search_canvas.side_effect = [mock_error]
+        handle_webhook(webhook.to_dict())
+        mock_logger.debug.assert_has_calls(
+            [call("Exiting with client error: %s", mock_error)],
+            any_order=True,
+        )