fix(collections): stricter enforcement on generics

[ycmjason]

Please see the following reproduction:

https://www.typescriptlang.org/play/?noUncheckedIndexedAccess=true#code/KYDwDg9gTgLgBAMwK4DsDGMCWEVzJtAawH0IAbAEwB4AVOUGYFCgZzggCMArYDAGjgBpeiEbM2hYAE8ICODQB8ACgBQcdtwBccAErAAhhRxkptBXzVxJUltqgGjKE0IDaAXQsBKbQAUChWgFBBTgAb0s0HBZ4exYkMngAXjCAXzh9Nj8iQKEFAG5LBGg4JUiUaKtpdjlrFk84TDklawbcTi562PiYF2s3OGT23uk3AvV7GCQoXC6EgpSVFVBIWERUDGxcfGy6BiZWDR5+ODKK4T3xOHtDYykS61l5T3dlS3btPRunU0ULdVrtIIvL5-DlBC4UEgALYcYBQNwhcLqU4xYBxBIDVLpTKgmhBCHQ2Hw-KFYqlKLwFqPWr1Rr3KqYNrcTpo7rDKT9QbcdmjSwTKYzVlzFQLJbgaDwZDoLA4PD+Yj6BK0ERiA7tXgwAQooQq-YSaSPRSqdTvXQOW5mP6VGx2c3fVweFTeOBZAJ43JhCIUq5CpJYjIu3FBEnqIpQEraqk1aR1BpNFqMw4s9E9PqYoZ9MY+ybTH0p+aLbVyZLKi4HPSRKDUaJQRkAcwEqEIKAgAHcUAplDBtDR6okQjACtrW1AcHWFeVW3DMQglNsSOQKEpQnAUPoocBtAByLgZHBbgT6OubuAAZgAjHAUgIXFu1xut25PJ4h97K-YMBOWFPw8lZ-Pl1XdcTx3PcUAPdJj20C8rxvO9gMfZ9X3KeB3w1L8fwVDE-zneVFRgQD7xA3cWH3Q8oLPS9rzgW8iMQl8VCAA

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As you can see above, the old typing will sometimes fail to narrow the second generic to fit the provided argument (in this example the second generic is inferred as "name" | "age" even the provided array is just ['name']. The new typing fixes the issue and also make the generics more aligned with the argument type.

I have also included an alternative fix for this but I feel like what I am proposing is better since it aligns the generics to the arguments better.

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Update: my proposed approach is breaking test when the input object is any. I have updated to use the alternative solution and added a test to cover this case.

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Side note: It is surprising to me that omit doesn't suffer from the same issue.

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[Copilot]

Pull request overview

This PR improves TypeScript type inference for the pick function by using the const type parameter modifier and restructuring the generic signature to ensure proper type narrowing when picking object properties.

Changes:

• Updated generic signature to use const K extends readonly (keyof T)[] instead of K extends keyof T
• Changed return type from Pick<T, K> to Pick<T, K[number]> to correctly extract union type from the array

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.21%. Comparing base (0aa59e2) to head (db91aee).
⚠️ Report is 22 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6961      +/-   ##
==========================================
+ Coverage   94.08%   94.21%   +0.12%     
==========================================
  Files         600      614      +14     
  Lines       43540    47791    +4251     
  Branches     6991     8303    +1312     
==========================================
+ Hits        40965    45026    +4061     
- Misses       2520     2698     +178     
- Partials       55       67      +12     

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[Copilot]

Pull request overview

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

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[ycmjason]

would need some help to fix test-bun 😄 i am not sure how to make it aware of @std/testing

[kt3k]

Good catch. Thanks for the contribution!