test: migrate stats/base/dists/discrete-uniform/logpmf 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/discrete-uniform/logpmf 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 relative error computations (previously tol = 1.0 * EPS * abs( expected[ i ] )) with isAlmostSameValue( y, expected[ i ], 1 ) assertions from @stdlib/assert/is-almost-same-value, and drops the now unused @stdlib/math/base/special/abs and @stdlib/constants/float64/eps imports.
• Updates test/test.logpmf.js, test/test.factory.js, and test/test.native.js. test/test.js is unchanged, as it contains no tolerance-based assertions.

Final ULP constant: 1 ULP, used uniformly across all three test files and all three fixture sets (small_range, medium_range, large_range).

Measured minimum. The bound was tightened agentically rather than guessed. Starting from a high bound and lowering it, the minimum ULP difference required to pass the full fixture set (3 × 1000 cases) is 1 for every implementation:

Fixture set	lib/main.js	lib/factory.js	lib/native.js
small_range	1	1	1
medium_range	1	1	1
large_range	1	1	1

1 is the tightest integer bound that holds: re-running the suite with 0 ULP produces 607 failures, so the bound cannot be lowered further.

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.

Verification performed:

• make test TESTS_FILTER=".*/stats/base/dists/discrete-uniform/logpmf/.*" is green: 3017 (test.factory.js) + 3011 (test.logpmf.js) + 3 (test.js) + 3006 (test.native.js) assertions passing, 0 failing.
• The native add-on was built locally (make install-node-addons NODE_ADDONS_PATTERN="discrete-uniform/logpmf") so that test.native.js was actually exercised at 1 ULP rather than skipped.
• The suite was run twice at the final bound with identical results, to rule out FMA/architecture-dependent flakiness.
• make lint-javascript-files with etc/eslint/.eslintrc.tests.js is clean, and the full pre-commit static analysis report passes.
• Only the three test files are changed.

One note on local tooling: the lint_editorconfig pre-commit task could not run in this environment, because editorconfig-checker downloads its binary from GitHub releases and the network egress available here blocks that fetch. The applicable EditorConfig rules for *.js were instead verified directly on the changed files (LF endings, UTF-8, tab indentation, no trailing whitespace, final newline present); CI will run the real check.

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 studied previously merged conversions in the same family (notably stats/base/dists/discrete-uniform/logcdf) to match the established idiom, applied the mechanical substitution, and then determined the minimum ULP bound empirically by running the test suite across candidate bounds.

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🤖 Generated with Claude Code

https://claude.ai/code/session_01FJKn4dpTUjRm6CFGRXBkdh

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[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/base/dists/discrete-uniform/logpmf	$\\color{green}291/291$ $\\color{green}+100.00\\%$	$\\color{green}31/31$ $\\color{green}+100.00\\%$	$\\color{green}4/4$ $\\color{green}+100.00\\%$	$\\color{green}291/291$ $\\color{green}+100.00\\%$

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