test(@stdlib/random/base/mt19937): bound seed growth in factory benchmark

[Planeshifter]

Resolves #{{TODO: add issue number}}.

Description

This pull request:

• fixes the factory:seed=<integer> benchmark in @stdlib/random/base/mt19937 so it no longer crashes the nightly random_benchmarks job.

Failing run: https://github.com/stdlib-js/stdlib/actions/runs/34173224406 (random_benchmarks, develop).

Symptom: RangeError: invalid option. seedoption must be a positive integer less than or equal to the maximum unsigned 32-bit integer. Option:4295022904. thrown from benchmark.factory.js, aborting the job.

Root cause: the factory:seed=<integer> benchmark accumulates the seed across iterations (opts.seed += i). That is a triangular-number sum (1 + Σi), which deterministically exceeds UINT32_MAX (4294967295) once the loop passes roughly 92700 iterations — reproduced locally, and it throws at the exact seed value (4295022904) reported in the failing run. This is unrelated to any specific develop commit; it reproduces on every SHA once the benchmark harness's iteration count crosses that threshold, which is why it fails on schedule rather than on a particular push.

Fix: assign a bounded, always-valid seed per iteration (opts.seed = i + 1) instead of accumulating. This matches the pattern already used by the sibling factory:seed=<array> benchmark two blocks below in the same file (opts.seed[ 0 ] = i + 1;), so the change is a one-line, in-idiom fix rather than a new approach.

Related Issues

No.

Questions

No.

Other

Validation:

• Reproduced the original failure locally by replaying the old loop logic directly against @stdlib/random/base/mt19937's factory: it throws at i = 92682, seed = 4295022904 — the exact value from the failing run.
• Replayed the fixed loop logic (200,000 iterations, well past the overflow threshold): completes with no error.
• Full lint/build tooling (make lint-javascript-benchmarks) was not runnable in this sandbox (no top-level node_modules installed); the diff is a single line that mirrors the existing sibling benchmark's exact style in the same file, so no formatting/lint drift is expected.
• Reviewed by three independent automated reviewers: correctness (confirmed the fix eliminates the unbounded accumulation and preserves a distinct, valid seed per iteration), regression scope (confirmed the change is isolated to this one file/benchmark and does not touch the factory/main implementation, tests, or docs), and style/conventions (confirmed the replacement matches the sibling seed=<array> benchmark's idiom and existing indentation exactly). All three approved with no blocking findings.

Reviewer notes (non-blocking):

• The identical accumulation pattern (opts.seed += i;) exists in the same-named benchmark across roughly 40 sibling @stdlib/random/base/* packages (e.g. beta, uniform, normal, minstd-shuffle, ...). None of those failed in this observation window, but each will hit the same overflow once its own benchmark run crosses ~92700 iterations. Fixing all of them is out of scope for this CI-failure fix (would cascade well beyond the reported failure); worth a dedicated follow-up sweep.

Checklist

• Read, understood, and followed the contributing guidelines.

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 as part of an automated CI-failure investigation and fix routine; the failure was reproduced locally against the actual mt19937 factory before and after the change, and the fix was independently reviewed by three automated reviewer passes before submission.

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@stdlib-js/reviewers

🤖 Generated with Claude Code

https://claude.ai/code/session_01AiQ7xQp83BfogoNxDNvNW8

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Coverage Report

Package	Statements	Branches	Functions	Lines
random/base/mt19937	$\\color{green}913/913$ $\\color{green}+100.00\\%$	$\\color{green}88/88$ $\\color{green}+100.00\\%$	$\\color{green}15/15$ $\\color{green}+100.00\\%$	$\\color{green}913/913$ $\\color{green}+100.00\\%$

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