Registry / testing / eslint-plugin-mocha-no-only

eslint-plugin-mocha-no-only

library1.2.0jsnpmunverified

This ESLint plugin, `eslint-plugin-mocha-no-only`, enforces a rule that prohibits the use of Mocha's `.only()` method on test keywords like `describe`, `context`, `it`, `specify`, `suite`, and `test`. Its primary purpose is to prevent developers from accidentally committing code that only runs a subset of their test suite, which can lead to false-positive CI/CD builds. The current stable version is `1.2.0`, which introduced support for ESLint v9.0.0 and updated internal dependencies. While there isn't a strict release cadence, the project is actively maintained to ensure compatibility with recent ESLint versions. It differentiates itself by providing a dedicated, straightforward solution for a common oversight in Mocha testing workflows, ensuring comprehensive test execution.

testing

npm install eslint-plugin-mocha-no-only

github ↗package ↗

INSTALL

IMPORT

SIG · ESLINT-PLUGIN-MOCH

eslint-plugin-mocha-no-only

testingjavascriptv1.2.0

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

mochaNoOnly

✓ import mochaNoOnly from "eslint-plugin-mocha-no-only";

✗ import { rules } from "eslint-plugin-mocha-no-only";

This import is for the plugin module itself, used in the 'plugins' object of the new ESLint flat configuration (eslint.config.js) since ESLint v9.

"mochaNoOnly/mocha-no-only"

✓ rules: { "mochaNoOnly/mocha-no-only": ["error"] }

✗ rules: { "mocha-no-only": ["error"] }

When configuring the rule, you must use the full ID including the plugin namespace 'mochaNoOnly/'.

require('eslint-plugin-mocha-no-only')

✓ module.exports = { plugins: ['mocha-no-only'], rules: { 'mocha-no-only/mocha-no-only': 'error' } };

✗ import mochaNoOnly from 'eslint-plugin-mocha-no-only'

For older CommonJS-based .eslintrc.js configurations (pre-ESLint v9), the plugin is typically added to the 'plugins' array by its name and resolved by ESLint.

Demonstrates how to set up `eslint-plugin-mocha-no-only` within the new ESLint flat configuration system (eslint.config.js), targeting only test files to prevent accidental `.only()` calls.

import globals from "globals"; import pluginJs from "@eslint/js"; import mochaNoOnly from "eslint-plugin-mocha-no-only"; export default [ // Base configuration (applies globally) { languageOptions: { globals: globals.node }, // Or globals.browser depending on your environment // You can add other global configurations here }, // Apply mocha-no-only specifically to test files { files: ["test/**/*.js", "test/**/*.ts", "**/__tests__/**/*.js"], plugins: { mochaNoOnly }, // Reference the imported plugin rules: { "mochaNoOnly/mocha-no-only": ["error"] } }, // Recommended ESLint JavaScript rules (optional, if desired) pluginJs.configs.recommended, ];

Debug

Known issues

breakingESLint v9 introduced a new flat configuration system (eslint.config.js) that is incompatible with the older .eslintrc.* files. While `eslint-plugin-mocha-no-only` v1.2.0 supports ESLint v9, users migrating to ESLint v9 must update their configuration files accordingly.

fix

Migrate your ESLint configuration from .eslintrc.* files to the new `eslint.config.js` format. Refer to the ESLint v9 migration guide and the plugin's README for examples on configuring the plugin in the new system.

affects: >=1.2.0

gotchaForgetting to remove `.only()` from Mocha tests can lead to false-positive CI builds, giving a misleading impression of full test suite success when only a subset of tests were executed.

fix

Ensure this plugin is configured with an 'error' severity in your ESLint setup and integrated into your CI pre-commit hooks or build process to catch these issues early before code is merged.

affects: *

gotchaWhen using older CommonJS-based ESLint configurations (`.eslintrc.js`), the plugin must be installed as a dev dependency and listed in the `plugins` array. The new flat configuration system (supported from `v1.2.0`) uses ESM imports for the plugin itself.

fix

For CommonJS projects, install with `npm install eslint-plugin-mocha-no-only --save-dev` and add `'mocha-no-only'` to the `plugins` array in your `.eslintrc.js`. For modern projects, consider upgrading ESLint and using the `eslint.config.js` flat config system.

affects: <1.2.0

Errors

Common errors & fixes

ESLint: Rule 'mochaNoOnly/mocha-no-only' was not found.

The ESLint plugin `eslint-plugin-mocha-no-only` is not correctly registered or installed in your project.

fix

In `eslint.config.js`, ensure you have `import mochaNoOnly from "eslint-plugin-mocha-no-only"` and the plugin is included in the `plugins` object (e.g., `{ plugins: { mochaNoOnly } }`). For older configs, verify `'mocha-no-only'` is present in your `plugins` array in `.eslintrc.*` and the package is installed.

error: Do not use `only()` in tests (mochaNoOnly/mocha-no-only)

The ESLint rule is correctly configured and has identified an instance of `.only()` being used in a Mocha test file, which the plugin is designed to prevent.

fix

Remove the `.only()` method call from the `describe`, `it`, `context`, or other Mocha keywords. If this is for temporary local debugging, use an ESLint disable comment (e.g., `// eslint-disable-next-line mochaNoOnly/mocha-no-only`) but ensure it's removed before committing.

TypeError: Cannot read properties of undefined (reading 'plugins')

This error typically occurs when attempting to use the new ESLint flat configuration (e.g., `eslint.config.js`) with an ESLint version older than v9, which does not support the new format.

fix

Upgrade your ESLint dependency to v9 or higher by running `npm install eslint@latest --save-dev`. Alternatively, if you cannot upgrade ESLint, you must revert to the older `.eslintrc.*` configuration file format.

Upgrade

Version history

1.2.0latest on npm

Audit

Dependencies

eslintrequiredPeer dependency, required to run ESLint rules and lint JavaScript/TypeScript code.

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/lewazo/eslint-mocha-no-only ↗

packagehttps://www.npmjs.com/package/eslint-plugin-mocha-no-only ↗