fix(@stdlib/string/base/atob): guard against undefined atob global

[Planeshifter]

Description

What is the purpose of this pull request?

This pull request:

• Fixes a ReferenceError: atob is not defined crash on Node.js v12/v14 in @stdlib/string/base/atob by guarding the module-scope reference to the atob global.

Related Issues

Does this pull request have any related issues?

This pull request has the following related issues:

• None.

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.

Failing run
linux_test #29681875444, jobs "Node.js v12" and "Node.js v14", branch develop.

Symptom

ReferenceError: atob is not defined
    at Object.<anonymous> (.../lib/node_modules/@stdlib/string/base/atob/lib/global.js:23:18)

Root cause
global.js did module.exports = atob; — a bare reference evaluated at require time. Node <16 doesn't define atob globally. index.js requires main.js (which requires global.js) unconditionally, before @stdlib/assert/has-atob-support ever runs, so the crash preempts the environment-detection logic meant to handle exactly this case.

Fix
global.js now reads:

var main = ( typeof atob === 'function' ) ? atob : null;
module.exports = main;

typeof on an undeclared identifier never throws. On Node 16+/browsers, behavior is unchanged — the native function is exported as before. hasAtobSupport() still gates the polyfill path in index.js; main.js's try/catch is untouched.

Validation

• vm sandbox with no global atob: global.js no longer throws, exports null.
• End-to-end on native-atob Node: atob('SGVsbG8sIHdvcmxk') → 'Hello, world' through global.js → main.js → index.js.
• npm test / make lint-pkg not runnable in this sandbox (no node_modules; npm install blocked by registry min-release-age policy on es-object-atoms@^1.1.2). node --check confirms valid syntax.
• Three independent reviews (correctness, regression-scope, style) — all approve, no blocking findings.

Reviewer notes
Non-blocking: fix is platform-agnostic and should also cover this failure class on other Node <16 matrix jobs (windows_test_npm_install, macos_test_npm_install), not just linux_test.

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

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• Code generation (e.g., when writing an implementation or fixing a bug)
• Test/benchmark generation
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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 primarily by Claude Code, running an automated CI-failure investigation and fix routine: it identified the failing run, diagnosed the root cause, authored the fix, and drafted this description, all based on the linked CI failure log.

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@stdlib-js/reviewers

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Generated by Claude Code

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
string/base/atob	$\\color{green}217/217$ $\\color{green}+100.00\\%$	$\\color{red}11/12$ $\\color{green}+91.67\\%$	$\\color{green}2/2$ $\\color{green}+100.00\\%$	$\\color{green}217/217$ $\\color{green}+100.00\\%$

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

[kgryte]

Isn't this a duplicate PR?

[Planeshifter]

Yes — this duplicates #13329, opened 2026-07-06 for the same root cause, still open and passing CI. I missed the open-PR check before starting this one. Closing in favor of #13329.

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Generated by Claude Code