test: migrate stats/incr/nanmae to ULP-based assertions

[kgryte]

Resolves a part of #11352.

Description

What is the purpose of this pull request?

This pull request:

• migrates the tests for stats/incr/nanmae from relative tolerance testing to ULP difference testing, per [RFC]: Migrate math/base/special packages from relative tolerance testing to ULP difference testing (tracking issue) #11352.
• replaces the @stdlib/constants/float64/eps import with @stdlib/assert/is-almost-same-value, removes the delta/tol scratch variables, and collapses the exact/within-tolerance branches into a single t.strictEqual( isAlmostSameValue( actual, expected, 0 ), true, 'returns expected value' ); assertion.

Final ULP constant: 0.

This is the measured minimum. Starting from 64, the bound was lowered until the smallest integer which still passes over the full set of test values was found; 0 passes, and 0 is the floor. Every accumulated value exercised by the fixture (1.0, 4.5, 6.0) is exactly representable, so the accumulator reproduces the expected value bit-for-bit and no slack is required. The bound is not vacuous: isAlmostSameValue( 6.0, 6.0 + 2**-50, 0 ) returns false, so a one-ULP regression would still fail the suite.

The suite was run twice at the final ULP value to confirm determinism (11 passing, 0 failing on both runs). There is no test.native.js for this package, so test/test.js is the only file changed.

Related Issues

Does this pull request have any related issues?

This pull request has the following related issues:

• [RFC]: Migrate math/base/special packages from relative tolerance testing to ULP difference testing (tracking issue) #11352

Questions

Any questions for reviewers of this pull request?

No.

Other

Any other information relevant to this pull request? This may include screenshots, references, and/or implementation notes.

• The conversion mirrors the idiom settled on in the already-migrated sibling package stats/incr/maape (test: migrate stats/incr/maape to ULP-based assertions #15628), which likewise uses an inline ULP literal of 0 for its incremental accumulator loop.
• Local verification: make test TESTS_FILTER=".*/stats/incr/nanmae/.*" passes (11/11) and make lint-javascript-tests TESTS_FILTER=".*/stats/incr/nanmae/.*" is clean.
• make lint-editorconfig-files could not run in this environment because the editorconfig-checker binary download was blocked by network policy. The changed file was verified manually against .editorconfig instead: LF line endings, UTF-8, tab indentation, no trailing whitespace, and a final newline.

Checklist

Please ensure the following tasks are completed before submitting this pull request.

• Read, understood, and followed the contributing guidelines.

AI Assistance

When authoring the changes proposed in this PR, did you use any kind of AI assistance?

• Yes
• No

If you answered "yes" above, how did you use AI assistance?

• Code generation (e.g., when writing an implementation or fixing a bug)
• Test/benchmark generation
• Documentation (including examples)
• Research and understanding

Disclosure

If you answered "yes" to using AI assistance, please provide a short disclosure indicating how you used AI assistance. This helps reviewers determine how much scrutiny to apply when reviewing your contribution. Example disclosures: "This PR was written primarily by Claude Code." or "I consulted ChatGPT to understand the codebase, but the proposed changes were fully authored manually by myself.".

This PR was authored by Claude Code running as an unattended scheduled task. It selected the package, mirrored the conversion idiom from already-merged ULP migration commits, searched for the minimum passing ULP bound by running the suite at decreasing values, and wrote this description. Opened as a draft for human review.

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@stdlib-js/reviewers

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Generated by Claude Code

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Coverage Report

Package	Statements	Branches	Functions	Lines
stats/incr/nanmae	$\\color{green}144/144$ $\\color{green}+100.00\\%$	$\\color{green}8/8$ $\\color{green}+100.00\\%$	$\\color{green}2/2$ $\\color{green}+100.00\\%$	$\\color{green}144/144$ $\\color{green}+100.00\\%$

The above coverage report was generated for the changes in this PR.