lesslint

1.0.3 verified Fri May 01 auth: no javascript maintenance

A Less CSS linter for checking code quality and style consistency. Version 1.0.3 (stable, low release cadence). Integrates with Less syntax checking, offering rule-based validation. Differentiated by being one of few dedicated Less linters, though development is sparse compared to stylelint with Less plugins.

Common errors

error Error: Cannot find module 'less' ↓

cause Missing peer dependency 'less'.

fix

npm install less

error TypeError: lesslint.lint is not a function ↓

cause Using CJS require with ESM-only package.

fix

Change to import lesslint from 'lesslint'.

error SyntaxError: Unexpected token '.' (when importing) ↓

cause Package is ESM but project is CJS.

fix

Set "type": "module" in package.json or use dynamic import().

Warnings

gotcha lesslint requires the 'less' package as a peer dependency; not installing it leads to runtime errors. ↓

fix Run 'npm install less' alongside lesslint.

gotcha lesslint is ESM-only; CommonJS require will fail with Module 'lesslint' does not provide an export named 'default'. ↓

fix Use import instead of require, or set type: "module" in package.json.

deprecated The 'rules' export is deprecated as of 1.0.3; it may be removed in future versions. ↓

fix Access rules directly from linter instance or use custom configuration.

breaking Version 1.0.0 removed the synchronous lint() API; all methods are now async. ↓

fix Update code to use async/await or promises.

Install

npm install lesslint

yarn add lesslint

pnpm add lesslint

Imports

lesslint

wrong

const lesslint = require('lesslint')

correct

import lesslint from 'lesslint'

Default ESM export; CJS not available since v1.0.0.

Linter

wrong

import Linter from 'lesslint/Linter'

correct

import { Linter } from 'lesslint'

Named export for class-based usage.

rules

wrong

const rules = require('lesslint').rules

correct

import { rules } from 'lesslint'

Named export for built-in rules configuration.

less
wrong
```
const less = require('less')
```
correct
```
import less from 'less'
```
Required peer dependency for Less parsing; must be ESM.

Quickstart

Lint a Less code string using lesslint. Demonstrates async linting with result messages.

import lesslint from 'lesslint';
import less from 'less';

const code = `@color: red;\n.class { color: @color; }`;

lesslint.lint(code).then(result => {
  console.log(result.messages);
}).catch(err => console.error(err));