chore: dev to main merge

[Ragini-Microsoft]

Purpose

This pull request improves input validation for the /api/chat endpoint, ensuring that requests with missing or empty message content are properly rejected with a 400 error unless an action is specified. It also updates and expands the test suite to verify these new validation rules.

API validation improvements:

• Added checks in handle_chat (in app.py) to return a 400 error if the request body is empty or if the message field is missing or contains only whitespace (unless an action is specified).

Testing updates:

• Updated and added tests in test_app.py to assert that the chat endpoint rejects empty or whitespace-only messages, as well as empty request bodies, with the appropriate 400 error response.
• Modified existing tests to expect 400 errors for missing message scenarios, and clarified that action-based requests can still have empty messages. [1] [2] [3]

Does this introduce a breaking change?

• Yes
• No

Golden Path Validation

• I have tested the primary workflows (the "golden path") to ensure they function correctly without errors.

Deployment Validation

• I have validated the deployment process successfully and all services are running as expected with this change.

[github-actions]

Coverage Report •

File	Stmts	Miss	Cover	Missing
src/backend
app.py	720	135	81%	47, 64, 71–76, 79, 84, 119–120, 165, 244, 262, 281, 288, 412–413, 519, 522, 525–527, 536–537, 540, 542–544, 553–556, 566–567, 570–576, 579–581, 587–588, 590, 601, 603–608, 611–613, 620, 630–631, 633, 730–734, 742, 745, 753, 756–759, 768–769, 772, 781, 783, 811, 820–821, 835–836, 855–856, 858–859, 866–867, 870–871, 1013–1015, 1019–1021, 1060–1061, 1099, 1102, 1104, 1130–1131, 1133–1135, 1137, 1156–1157, 1159–1160, 1229–1230, 1261–1262, 1339–1340, 1600–1602, 1604–1605, 1612–1614, 1616, 1751, 1769, 1831–1832, 1836–1837
src/tests
test_app.py	1588	6	99%	1088, 1114, 3356–3357, 3375–3376
TOTAL	7680	379	95%

Tests	Skipped	Failures	Errors	Time
422	0 💤	0 ❌	0 🔥	14.552s ⏱️

[Copilot]

Pull request overview

This PR tightens /api/chat request validation so empty request bodies and missing/blank messages are rejected unless an explicit action is provided, and updates backend tests to reflect the new validation behavior.

Changes:

• Added early 400 responses in handle_chat for empty request data and blank message content.
• Updated chat endpoint tests to expect validation failures for missing/empty messages.
• Added coverage for whitespace-only messages and action-based empty-message requests.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/backend/app.py	Adds request-body and message-content validation to /api/chat.
src/tests/test_app.py	Updates and adds tests for the new chat validation behavior.

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