pick_random_key algorithm parameter is optional

[azmeuk]

Actually that was already available, but this adds a default value and a unit test.

[Copilot]

Pull request overview

This PR makes the algorithm parameter optional in the pick_random_key method by adding a default value of None. When no algorithm is specified, the method falls back to selecting randomly from all keys in the set.

• Added default value None to the algorithm parameter in pick_random_key method signature
• Added a unit test to verify the method works correctly when called without arguments

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/joserfc/_keys.py	Updated pick_random_key method signature to make algorithm parameter optional with default value None
tests/jwk/test_jwk_set.py	Added test case to verify pick_random_key() can be called without arguments and returns a key

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (bc13ead) to head (ee046b2).

Additional details and impacted files

@@            Coverage Diff            @@
##              main       #83   +/-   ##
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  Coverage   100.00%   100.00%           
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  Files           47        47           
  Lines         2850      2850           
  Branches       320       320           
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  Hits          2850      2850           

Flag	Coverage Δ
unittests	100.00% <100.00%> (ø)

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[lepture]

The method is used in jwk.guess_key, and jwe._guess_sender_key

return_key = resolved_key.pick_random_key(headers["alg"], parameters)

skey = key.pick_random_key(headers["alg"])

When this method is used, the algorithm name is always known.

[azmeuk]

I was thinking of other use cases. For example, in an OIDC server, if a client has not been set a favorite alg for signing, one might want to just use a random key among the keys available, and call pick_random_key without argument.