remark-lint-heading-whitespace

1.0.0 verified Fri May 01 auth: no javascript

remark-lint rule that detects non-breaking spaces (U+00A0) inserted accidentally after heading markers (e.g., '# ' instead of '# '), which causes headings to be parsed as plain paragraphs. Version 1.0.0 (latest) is stable and targets the remark-lint plugin ecosystem. No known release cadence. Differentiates from other lint rules by focusing on a specific, localization-driven typo that is common on keyboard layouts like Swiss German where '#' is typed via Alt+3 and Alt+Space produces a non-breaking space. Integrates as a remark-lint plugin.

Common errors

error Error [ERR_REQUIRE_ESM]: require() of ES Module not supported ↓

cause Attempting to require() the ESM-only package in a CommonJS context.

fix

Use import() or set 'type':'module' in package.json.

error TypeError: remarkLintHeadingWhitespace is not a function ↓

cause Named import used instead of default import.

fix

Use import remarkLintHeadingWhitespace from 'remark-lint-heading-whitespace' (default import).

Warnings

gotcha Package is ESM-only. Using CommonJS require() will fail with ERR_REQUIRE_ESM. ↓

fix Use dynamic import() or set 'type':'module' in package.json.

gotcha The rule does not automatically apply; it must be added as a plugin to remark with .use(lint) and .use(remarkLintHeadingWhitespace). ↓

fix Ensure both remark-lint and this rule are included in the remark pipeline.

Install

npm install remark-lint-heading-whitespace

yarn add remark-lint-heading-whitespace

pnpm add remark-lint-heading-whitespace

Imports

default

wrong

const remarkLintHeadingWhitespace = require('remark-lint-heading-whitespace')

correct

import remarkLintHeadingWhitespace from 'remark-lint-heading-whitespace'

ESM-only package; does not provide a CommonJS export. Use dynamic import or ensure Node.js >= 12 with 'type':'module'.

remarkLintHeadingWhitespace

wrong

import { remarkLintHeadingWhitespace } from 'remark-lint-heading-whitespace'

correct

import remarkLintHeadingWhitespace from 'remark-lint-heading-whitespace'

The package exports a single default function; named import does not exist.

Quickstart

Shows how to use the rule with remark, processing a heading containing a non-breaking space and outputting lint warnings.

import { remark } from 'remark';
import lint from 'remark-lint';
import remarkLintHeadingWhitespace from 'remark-lint-heading-whitespace';

const file = await remark()
  .use(lint)
  .use(remarkLintHeadingWhitespace)
  .process('#\u00A0bad heading');

console.log(String(file)); // includes warning about non-breaking space