mocha-eslint

7.0.0 verified Sat Apr 25 auth: no javascript

Run ESLint as Mocha tests without a task runner like Grunt or Gulp. Version 7.0.0 supports ESLint ^7.0.0 and requires Node ^10.12.0 or >=12.0.0. It creates separate Mocha tests for each linted path or glob pattern, with options for formatter, timeout, slow, strict mode, and context name. Unlike alternatives that require plugin registration, this package directly exposes a function to run linting in any Mocha test file.

Common errors

error Error: Cannot find module 'eslint' ↓

cause ESLint is not installed or not installed as a peer dependency.

fix

Run npm install eslint --save-dev

error TypeError: lint is not a function ↓

cause Using named import instead of default import.

fix

Use const lint = require('mocha-eslint');

error Mocha error: timeout of 2000ms exceeded ↓

cause Linting takes longer than the default Mocha timeout.

fix

Set the timeout option in mocha-eslint or globally in Mocha.

Warnings

breaking Version 7.0.0 updates ESLint to ^7.0.0. ESLint 7 includes breaking changes such as removal of some rules and configuration changes. ↓

fix Review ESLint 7 migration guide for rule and config changes.

breaking Version 6.0.0 drops support for Node 6 and updates to ESLint 6 and Mocha 6. ↓

fix Use Node >=8.0.0. Update ESLint config for version 6 changes.

breaking Version 5.0.0 drops Node <6 support and updates ESLint to ^5.10.0. ↓

fix Ensure Node >=6.0.0. Review ESLint 5 migration.

gotcha Mocha must be installed separately; mocha-eslint does not include it. ↓

fix Install mocha as a devDependency: npm install --save-dev mocha.

gotcha Negation patterns (e.g., !tests/NotATest.js) must be at the end of the paths array or they will not work. ↓

fix Place negation patterns after all positive patterns in the array.

Install

npm install mocha-eslint

yarn add mocha-eslint

pnpm add mocha-eslint

Imports

default
wrong
```
import lint from 'mocha-eslint';
```
correct
```
const lint = require('mocha-eslint');
```
Package uses CommonJS; ESM import may fail in older Node or without transpiler.
Value
```
const lint = require('mocha-eslint');
```
The exported value is a function; no named exports.

Type

wrong

import { lint } from 'mocha-eslint';

correct

const lint = require('mocha-eslint');

There is no named export; must import default.

Quickstart

Configure mocha-eslint with paths, formatter style, timeout, and strict mode, then run linting as Mocha tests.

const lint = require('mocha-eslint');
const paths = ['src', 'test/**/*.js', '!test/exclude.js'];
const options = {
  formatter: 'stylish',
  alwaysWarn: true,
  timeout: 5000,
  slow: 1000,
  strict: false,
  contextName: 'eslint'
};
lint(paths, options);