[eunwoo-levi]

Problem

When multiple negative indices are passed to pullAt, earlier splice calls shift the array length, causing subsequent negative indices to reference wrong elements.

  const arr = [10, 20, 30, 40, 50];
  pullAt(arr, [-1, -2]);
  // Expected: arr = [10, 20, 30]  (remove 50 and 40)
  // Actual:   arr = [10, 20, 40]  (remove 50 and 30)

Solution

Normalize negative indices to positive indices before splicing, so that array length changes don't affect which elements are removed.

Test

• Added tests for single, multiple, and mixed negative indices

[vercel]

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Project	Deployment	Actions	Updated (UTC)
es-toolkit	Ready	Preview	Aug 16, 2026 7:03am

[Copilot]

Pull request overview

Fixes pullAt so multiple negative indices remove the intended elements by converting negative indices to their positive equivalents before splicing, preventing index drift caused by earlier splice() calls.

Changes:

• Normalize negative indices to positive indices prior to sorting/deduping and splicing.
• Add unit tests covering single, multiple, and mixed negative indices.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/array/pullAt.ts	Normalizes negative indices before sorting and splicing to avoid incorrect removals.
src/array/pullAt.spec.ts	Adds coverage for negative-index scenarios (single, multiple, and mixed).

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[Copilot]

normalizedIndices only adds arr.length for negative values, but doesn’t apply the same integer coercion / bounds handling as at(). This can cause pullAt to mutate the array for out-of-range negative indices (e.g. index < -arr.length becomes a negative normalized index and splice will remove from the end) even though at() returns undefined for those keys. Consider normalizing indices using the same rules as at() (truncate non-integers, add length for negatives) and then filtering out indices that are still out of [0, length) before splicing, so nonexistent indices don’t remove unrelated elements.

Suggested change

	const normalizedIndices = indicesToRemove.map(index => (index < 0 ? arr.length + index : index));
	const length = arr.length;
	const normalizedIndices = indicesToRemove
	.map((index) => {
	let idx = Math.trunc(index);
	if (idx < 0) idx += length;
	return idx;
	})
	.filter((idx) => idx >= 0 && idx < length);

[Copilot]

The new negative-index tests cover in-range negatives, but there’s still no coverage for out-of-range negatives (e.g. index < -array.length). Given at() returns undefined for those, it would be good to add a case asserting pullAt also returns undefined and does not remove any element for such indices.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.85%. Comparing base (0e8656d) to head (ff1991a).
⚠️ Report is 161 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1613   +/-   ##
=======================================
  Coverage   99.85%   99.85%           
=======================================
  Files         499      499           
  Lines        4670     4671    +1     
  Branches     1357     1358    +1     
=======================================
+ Hits         4663     4664    +1     
  Misses          7        7           

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