[Hardik K (hardikkaurani)]

Description

In HeadersCollection.remove_value, calling remove_value with a value not present in an existing header previously caused an unhandled KeyError exception because set.remove(...) was invoked directly without verifying value membership. In contrast, calling remove_value on a non-existent header gracefully returned False.

Additionally, when removing the final remaining value of a header, remove_value previously returned set(), which evaluates to False in Python boolean contexts (bool(set()) == False), giving callers a false-negative status even though removal succeeded and the header was popped.

This PR addresses both issues:

1. Safe Missing Value Handling: Verifies header_value in values before removing; returns False if the value is not present, avoiding unhandled KeyError exceptions.
2. Normalized Return Semantics: Returns True when the value was removed and no values remain in the header (cleaning up the key from the internal mapping), returns the remaining set[str] when other values remain, and returns False when the header or value was not found.
3. Documentation: Updated docstrings on remove_value and remove to accurately reflect their Union[bool, set[str]] return types.

Changes

• packages/abstractions/kiota_abstractions/headers_collection.py:
  • Added membership check in remove_value to return False if header_value not in values.
  • Returned True when the header is fully cleared and removed after removing its last value.
  • Updated docstring return annotations for remove_value and remove.
• packages/abstractions/tests/test_request_header.py:
  • Added test for removing a non-existent value from an existing header returning False without raising KeyError.
  • Added test verifying header name case-insensitivity on removal.
  • Added assertions for return semantics on multi-value removal, last-value removal, and header removal.

Testing

• Verified with pytest packages/abstractions: 194/194 passed.
• Verified with pylint kiota_abstractions: rated 10.00/10.
• Verified with mypy kiota_abstractions: 0 issues found across 48 source files.
• Verified code formatting with yapf and import sorting with isort.
• Ran regression test suites across serialization and http packages.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[Copilot]

🟢 Approval recommended

No active review issues block approval of the header-value removal changes.

No open issues 🎉

What changed in this PR

This PR makes header-value removal safer in Kiota’s abstractions layer and clarifies its return semantics.

Changes:

• Returns False when a value is absent instead of raising KeyError.
• Returns True after removing a header’s final value, while preserving the remaining-set return for partial removal.
• Updates return-value documentation and adds regression coverage for missing values, case-insensitive header names, and removal results.

File	Description
packages/​abstractions/​tests/​test_request_header.py	Adds and strengthens assertions for removal behavior and return values.
packages/​abstractions/​kiota_abstractions/​headers_collection.py	Safely handles absent values, fixes final-value removal results, and documents return types.

_{Review effort: Balanced}