[kgryte]

Resolves a part of #11352.

Description

What is the purpose of this pull request?

This pull request:

• migrates the tests for stats/base/dists/beta/skewness 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.

Specifically, in both test/test.js and test/test.native.js, the exact-match/relative-tolerance branch in the fixture loop

if ( y === expected[i] ) {
    t.strictEqual( y, expected[i], ... );
} else {
    delta = abs( y - expected[ i ] );
    tol = 1.0 * EPS * abs( expected[ i ] );
    t.ok( delta <= tol, ... );
}

is replaced by

t.strictEqual( isAlmostSameValue( y, expected[ i ], 0 ), true, 'returns expected value' );

along with adding the @stdlib/assert/is-almost-same-value require and removing the now unused @stdlib/math/base/special/abs and @stdlib/constants/float64/eps requires and the delta/tol declarations.

ULP bound

• Final ULP constant: 0 (used in both test/test.js and test/test.native.js).
• Measured minimum: 0. Starting from a bound of 64, the bound was lowered while the suite continued to pass. Over the full Julia fixture set (1000 cases in test/fixtures/julia/data.json), the maximum ULP difference between the returned and expected values is 0, i.e., every returned value is bit-identical to the expected value, so 0 is the tightest possible bound.
• The suite was run twice at the final bound to confirm determinism (1014/1014 assertions passing on both runs).

This is consistent with the implementation: both the JavaScript and C implementations evaluate the same expression using only correctly rounded IEEE 754 operations (+, -, *, /, and sqrt), with no FMA-contractible a*b + c pattern, so the result is expected to be reproducible across platforms.

Note that test/test.native.js is skipped in this environment because the native add-on is not built; the bound there matches the JavaScript bound, as in previously migrated packages.

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.

Only the two test files are modified; no source, documentation, benchmark, or fixture files are touched.

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 task. It studied previously merged migrations (e.g., stats/base/dists/beta/entropy) to mirror the established idiom, applied the mechanical test refactor, and empirically determined the minimum ULP bound by running the package's test suite.

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@stdlib-js/reviewers

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Generated by Claude Code

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/base/dists/beta/skewness	$\\color{green}201/201$ $\\color{green}+100.00\\%$	$\\color{green}10/10$ $\\color{green}+100.00\\%$	$\\color{green}2/2$ $\\color{green}+100.00\\%$	$\\color{green}201/201$ $\\color{green}+100.00\\%$

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