chore: fix JavaScript lint errors (issue #8483)

[Sumithraju]

Summary

Replace out instanceof Error with isError( out ) using @stdlib/assert/is-error to comply with the stdlib/doctest linting rule in the @stdlib/fs/read-dir examples file.

Fixes #8483

Description

This pull request addresses a JavaScript linting error identified in issue #8483. The stdlib/doctest rule reported a mismatch at line 33 of examples/index.js: "Displayed return value is true, but expected false instead."

The root cause is that out instanceof Error is not properly tracked by the doctest rule when the variable is reassigned. The fix replaces instanceof Error checks with the isError() utility from @stdlib/assert/is-error, matching the established pattern used in similar packages like @stdlib/fs/read-file.

Changes Made

• File: lib/node_modules/@stdlib/fs/read-dir/examples/index.js
• Added import: var isError = require( '@stdlib/assert/is-error' );
• Line 29: console.log( out instanceof Error ) → console.log( isError( out ) )
• Line 35: console.log( out instanceof Error ) → console.log( isError( out ) )
• Impact: No functional change; identical behavior, resolves doctest lint error

Related Issues

Resolves #8483

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature
• Breaking change
• Documentation update

Testing

No functional changes required testing. The isError() utility provides identical behavior to instanceof Error checks. The doctest annotations (// => false and // => true) remain correct.

AI Assistance

• Yes (Lint error analysis, pattern identification, fix implementation)

AI Disclosure

"This PR was authored with AI assistance. AI analyzed the doctest linting violation, identified the root cause (instanceof operator not tracked by the doctest rule), found the established fix pattern from @stdlib/fs/read-file, and implemented the replacement using @stdlib/assert/is-error. The proposed change maintains identical functionality and follows all contribution guidelines."

Checklist

• Read, understood, and followed the contributing guidelines
• Code adheres to project standards
• Change is properly documented
• Linting compliance verified

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
fs/read-dir	$\color{green}171/171$ $\color{green}+100.00%$	$\color{green}7/7$ $\color{green}+100.00%$	$\color{green}2/2$ $\color{green}+100.00%$	$\color{green}171/171$ $\color{green}+100.00%$

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