test: migrate stats/base/dists/logistic/entropy to ULP-based assertions

[kgryte]

Description

What is the purpose of this pull request?

This pull request:

• migrates the tests for stats/base/dists/logistic/entropy from relative tolerance (EPS-based) comparisons to ULP-based assertions, 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 fixture loop's delta/tol computation is replaced with

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

adding a @stdlib/assert/is-almost-same-value require and dropping the now-unused @stdlib/math/base/special/abs and @stdlib/constants/float64/eps requires.

Final ULP constant: 0 (both test.js and test.native.js).

The bound was tightened empirically rather than assumed. Starting from 64 and lowering, the minimum passing integer over the full fixture set (100 non-null cases) is 0:

• at N = 0: 110/110 assertions pass.

The maximum observed ULP difference across the fixtures is 0; every fixture value is returned exactly, so the previous 2.0 * EPS relative tolerance was never actually exercised. test.js was run twice at the final N with identical results.

The native test is skipped locally (the addon is not built in this environment), but the same bound is safe by construction, and this was checked rather than assumed. Both lib/main.js and src/main.c compute ln( s ) + 2.0 using stdlib's own ln, so the C implementation was compiled directly (stdlib_base_ln plus its dependency closure, via gcc) and evaluated over the 100 fixture s values: the results are bit-identical to the JavaScript implementation and match the Julia fixtures to 0 ULP. The single addition admits no FMA contraction, so the measured bound carries over to the native path.

Only the two test files are modified; no implementation, fixture, or documentation changes.

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.

make install-node-modules initially failed in the authoring environment with ETARGET: No matching version found for es-object-atoms@^1.1.2 (the reachable registry publishes only up to 1.1.1). This was worked around by installing the dev dependencies into an isolated scratch tree with an npm overrides entry pinning es-object-atoms to 1.1.1, so the project toolchain could be exercised for real:

• make test TESTS_FILTER=".*/stats/base/dists/logistic/entropy/.*" — green (110 passing; native suite skipped, addon not built);
• eslint with etc/eslint/.eslintrc.tests.js on both changed files — clean;
• the pre-commit hook's filename, package.json, REPL-help, and JavaScript test lint steps — clean.

The one check that could not be run is lint-editorconfig-files, which downloads the editorconfig-checker binary from GitHub and is blocked by this environment's network policy. The changed files were verified manually against .editorconfig instead: LF line endings, UTF-8, tab indentation, no trailing whitespace, final newline present.

Leaving this as a draft so CI can confirm the full lint and the native builds.

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 written by Claude Code running as an unattended scheduled task. It surveyed prior merged conversions (e.g. #14211, #14213) to match the established idiom, applied the test changes, and determined the minimum ULP bound empirically against the full fixture set.

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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/base/dists/logistic/entropy	$\\color{green}176/176$ $\\color{green}+100.00\\%$	$\\color{green}9/9$ $\\color{green}+100.00\\%$	$\\color{green}2/2$ $\\color{green}+100.00\\%$	$\\color{green}176/176$ $\\color{green}+100.00\\%$

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