remark-lint-emphasis-marker

4.0.1 verified Fri May 01 auth: no javascript

remark-lint rule to warn when emphasis markers (asterisks vs underscores) violate a given or consistent style. Current stable version is 4.0.1, ESM-only, requires Node.js 16+. Part of the unified/remark ecosystem, ships TypeScript types. Integrates with remark-lint presets like `remark-preset-lint-consistent` and `remark-preset-lint-markdown-style-guide`. Distributed as a scoped package on npm. Includes CLI support via remark CLI.

Common errors

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

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

fix

Switch to import syntax: import remarkLintEmphasisMarker from 'remark-lint-emphasis-marker';

error TypeError: remarkLintEmphasisMarker is not a function ↓

cause Missing or incorrect usage with unified: possibly forgot .use() or passed options incorrectly.

fix

Ensure correct usage: unified().use(remarkLintEmphasisMarker, '*'). The function is a plugin, not a standalone linter.

error Cannot find module 'remark-lint' ↓

cause Missing required peer dependency 'remark-lint'.

fix

Install remark-lint: npm install remark-lint

Warnings

breaking Package is ESM-only starting from v4.0.0. Requires Node.js 16+ and cannot be required with CommonJS. ↓

fix Use import syntax and ensure Node.js 16+. If you must use CommonJS, stick with v3.x.

gotcha The default option is 'consistent', which auto-detects the first emphasis marker and warns on mismatches. Explicitly setting to '*' or '_' enforces that specific marker. ↓

fix Specify the desired marker explicitly to avoid unexpected behavior: .use(remarkLintEmphasisMarker, '*')

deprecated TypeScript type Options previously accepted arbitrary strings; now tightly typed as Marker | 'consistent'. ↓

fix Update TypeScript usage to only use '*' | '_' | 'consistent'.

gotcha Only supports '*' and '_' markers. Other characters (like '~') are not valid for emphasis in Markdown and are ignored by this rule. ↓

fix Use only '*' or '_' for emphasis markers in Markdown content.

Install

npm install remark-lint-emphasis-marker

yarn add remark-lint-emphasis-marker

pnpm add remark-lint-emphasis-marker

Imports

default

wrong

const remarkLintEmphasisMarker = require('remark-lint-emphasis-marker')

correct

import remarkLintEmphasisMarker from 'remark-lint-emphasis-marker'

Package is ESM-only since v4. CommonJS require will throw an error.

type Marker
wrong
```
import { Marker } from 'remark-lint-emphasis-marker'
```
correct
```
import type { Marker } from 'remark-lint-emphasis-marker'
```
Marker is a TypeScript type export, not a runtime value. Use 'import type' or 'import { type Marker }'
type Options
wrong
```
import { Options } from 'remark-lint-emphasis-marker'
```
correct
```
import type { Options } from 'remark-lint-emphasis-marker'
```
Options is a TypeScript type export, not a runtime value. Use 'import type' or 'import { type Options }'

Quickstart

Lint emphasis markers in a Markdown file, enforcing asterisks as the preferred marker.

import { unified } from 'unified';
import remarkParse from 'remark-parse';
import remarkStringify from 'remark-stringify';
import remarkLint from 'remark-lint';
import remarkLintEmphasisMarker from 'remark-lint-emphasis-marker';
import { read } from 'to-vfile';
import { reporter } from 'vfile-reporter';

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

await unified()
  .use(remarkParse)
  .use(remarkLint)
  .use(remarkLintEmphasisMarker, '*')
  .use(remarkStringify)
  .process(file);

console.error(reporter(file));