fix(types): improve draw signature for non-empty arrays

[crishoj]

Summary

This is a renewed attempt at narrowing the return type for draw(), so that emptiness of the array argument is taken into account.

• For literal array arguments, return type can be determined as T or null.
• For mutable array arguments, return type remains T|null.
• For immutable array arguments,
  • return type remains T|null for empty arrays (not sure why)
  • return type is narrowed to T for non-empty arrays.

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Disclosure: I am a Typescript novice and welcome your feedback.

If the approach is sound, similar overrides could be considered for

• first
• last

Related issue, if any:

• Previous attempt: feat(draw): add overloads for empty and non-empty arrays #139

For any code change,

• Related tests have been added or updated, if needed

Does this PR introduce a breaking change?

No

[MarlonPassos-git]

Good job @crishoj, now we don't have that false positive.

[MarlonPassos-git]

Deleting that line is all ok

[radashi-bot]

Benchmark Results

Name	Current	Baseline	Change
draw ▶︎ with valid input	1,068,168.13 ops/sec ±0.33%	1,088,828.86 ops/sec ±0.58% 🔗	🐢 -1.9%

Generally speaking, any regression ≥20% should be investigated if it wasn't to be expected.

[aleclarson]

I've updated the signature to ensure inlined arrays are properly handled at the type level:

const val = draw([1, 2, 3])
//    ^? 1 | 2 | 3

[radashi-bot]

A stable release 12.2.2 has been published to NPM. 🚀

To install:

pnpm add [email protected]

[crishoj]

Excellent, thanks for the improvement.

T[number] to get element type — TIL.