remark-lint-maximum-line-length

4.1.1 verified Fri May 01 auth: no javascript

A remark-lint rule that warns when lines in Markdown files exceed a configurable maximum length. Version 4.1.1 is the current stable release, part of the remark-lint monorepo. It is ESM-only, requires Node.js 16+, and ships TypeScript types. Unlike general linters, it respects Markdown node types (e.g., ignores code blocks, tables, and long URLs/links that cannot be wrapped). Supports a custom stringLength function for accurate character width measurement. Active development, updated regularly with other remark-lint packages.

Common errors

error Cannot find module 'remark-lint-maximum-line-length' ↓

cause Package not installed or incorrect import path.

fix

Run 'npm install remark-lint-maximum-line-length' and ensure you use the default import.

error ERR_REQUIRE_ESM ↓

cause Using require() on an ESM-only package.

fix

Change to import statement or use dynamic import().

error TypeError: remarkLintMaximumLineLength is not a function ↓

cause Using a named import instead of default import.

fix

Use 'import remarkLintMaximumLineLength from ...' (without braces).

error TypeError: Cannot read properties of undefined (reading 'type') ↓

cause Missing remark-parse or remark-lint plugin in the pipeline.

fix

Ensure you use remarkParse and remarkLint before the rule.

Warnings

breaking Package is ESM-only since v3. CommonJS require() will throw an error. ↓

fix Use import statement instead of require(). If you must use CommonJS, use dynamic import() or stay on v2.x.

breaking Default options changed from size=80 to size=60 in v4. ↓

fix Explicitly set size option if you expect 80 characters.

deprecated The option 'maxLineLength' was renamed to 'size' in v4. ↓

fix Use the 'size' option instead of 'maxLineLength'.

gotcha The rule ignores nodes that cannot be wrapped (e.g., code blocks, tables, long URLs). Users may expect warnings for all lines. ↓

fix No fix; this is by design. Review the documentation to understand which lines are checked.

gotcha The CLI plugin name must use kebab-case: 'remark-lint-maximum-line-length', not camelCase. ↓

fix Use the correct kebab-case name in CLI commands.

Install

npm install remark-lint-maximum-line-length

yarn add remark-lint-maximum-line-length

pnpm add remark-lint-maximum-line-length

Imports

remarkLintMaximumLineLength

wrong

const { remarkLintMaximumLineLength } = require('remark-lint-maximum-line-length')

correct

import remarkLintMaximumLineLength from 'remark-lint-maximum-line-length'

Default export only. Use ESM import; CommonJS require is not supported because the package is ESM-only.

Options
```
import type { Options } from 'remark-lint-maximum-line-length'
```
TypeScript type import for configuration options. Not available as a value.
remarkLintMaximumLineLength (CLI usage)
wrong
```
remark --use remarkLintMaximumLineLength
```
correct
```
remark --use remark-lint-maximum-line-length
```
CLI plugin name is kebab-case, not camelCase.

Quickstart

Demonstrates linting a Markdown file with a maximum line length of 80, using the unified pipeline.

import { unified } from 'unified';
import remarkParse from 'remark-parse';
import remarkStringify from 'remark-stringify';
import remarkLint from 'remark-lint';
import remarkLintMaximumLineLength from 'remark-lint-maximum-line-length';
import { read } from 'to-vfile';
import { reporter } from 'vfile-reporter';

const file = await read('example.md');

const result = await unified()
  .use(remarkParse)
  .use(remarkLint)
  .use(remarkLintMaximumLineLength, { size: 80 })
  .use(remarkStringify)
  .process(file);

console.error(reporter(result));