feat: added switcher.default_result() fall back feature

[petruki]

This pull request introduces support for setting a default result when feature flag criteria evaluation fails, both for local and remote strategies. This ensures that the application can gracefully handle errors by returning a predefined result instead of raising exceptions, and provides improved error notification and logging. The PR also updates documentation and adds comprehensive tests for these new behaviors.

Default result support and error handling:

• Added a default_result method to the Switcher class, allowing users to specify a fallback result if criteria evaluation fails. The implementation ensures that, in case of errors (e.g., missing config, remote API failure), the default result is returned and the error is logged or notified. (switcher_client/switcher_data.py [1] [2]; switcher_client/switcher.py [3]
• Introduced the _get_default_result_or_raise helper to encapsulate fallback logic and error notification when criteria checks fail. (switcher_client/switcher.py switcher_client/switcher.pyR93-R125)
• Added a static create method to ResultDetail for easier instantiation in fallback scenarios. (switcher_client/lib/types.py switcher_client/lib/types.pyR9-R12)

Documentation updates:

• Updated the README.md to demonstrate chaining of validation strategies, including the new default_result and throttle methods for robust feature control. (README.md README.mdL212-R220)

Testing improvements:

• Added tests to verify that default_result is correctly returned on local and remote evaluation failures, and that error notifications are triggered as expected. (tests/test_switcher_local.py [1] [2] [3]; tests/test_switcher_remote.py [4] [5]

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

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