test: migrate stats/base/dists/bradford/quantile 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/base/dists/bradford/quantile 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 delta/tol (3.2 * EPS * abs( expected[i] ) and 4.8 * EPS * abs( expected[i] )) comparisons in test/test.quantile.js, test/test.factory.js, and test/test.native.js with t.strictEqual( isAlmostSameValue( y, expected[ i ], N ), true, 'returns expected value' );, adding the @stdlib/assert/is-almost-same-value import and removing the now unused @stdlib/math/base/special/abs and @stdlib/constants/float64/eps imports.

Final ULP constants (identical across all three test files):

Fixture	ULP bound
small_c.json	5
medium_c.json	6
large_c.json	7

These are the measured minimums. Starting from a high bound and tightening, the maximum ULP difference over the full 1000-case-per-group Python fixture set is exactly 5, 6, and 7 respectively. Each bound was verified to be minimal: lowering any one of them by a single ULP produces failing assertions (1, 1, and 2 failures respectively). The bounds hold identically for the JavaScript and native implementations, so the same values apply to all three files.

The suite was run twice at the final bounds with identical results, and the native addon was compiled locally so that test/test.native.js actually executed rather than being skipped:

• test/test.js: 3 passing, 0 failing
• test/test.quantile.js: 3011 passing, 0 failing
• test/test.factory.js: 3013 passing, 0 failing
• test/test.native.js: 3011 passing, 0 failing

test/test.js contains only export smoke tests and is unchanged. The expected[i] !== null guards in test/test.native.js are preserved. Only the three test files containing tolerance math are 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 sibling package stats/base/dists/bradford/cdf, which uses the same three-fixture structure and per-fixture-group ULP bounds.

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

This PR was authored by Claude Code running as an automated task. The tolerance-to-ULP conversion, the search for the minimum ULP bounds, and the local test/lint verification were all performed by Claude Code.

---

@stdlib-js/reviewers

🤖 Generated with Claude Code

https://claude.ai/code/session_012wtya3dXa2SDCVsefgMHKb

---

Generated by Claude Code

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/base/dists/bradford/quantile	$\\color{green}290/290$ $\\color{green}+100.00\\%$	$\\color{green}21/21$ $\\color{green}+100.00\\%$	$\\color{green}4/4$ $\\color{green}+100.00\\%$	$\\color{green}290/290$ $\\color{green}+100.00\\%$

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