eslint-plugin-jasmine

4.2.2 verified Sat Apr 25 auth: no javascript

ESLint plugin providing linting rules for Jasmine test suites. Current stable version is 4.2.2 (September 2024). Release cadence is irregular with minor patches and occasional feature releases. Key differentiators: it is the most widely used ESLint plugin for Jasmine, with a comprehensive set of rules covering common anti-patterns like focused tests, disabled tests, missing expectations, and improper use of spies. Includes a recommended configuration. Note: v4.2.0+ supports ESLint v9 flat config with some caveats (beta). Requires Node >=8 and npm >=6. Alternative: eslint-plugin-jasmine-no-describe-variables (lighter scope).

Common errors

error Definition for rule 'jasmine/prefer-toBeUndefined' was not found ↓

cause Rule was added in v4.1.0 but some configurations might have a typo or old version.

fix

Update to eslint-plugin-jasmine@4.1.2+ and ensure rule name is correct: 'prefer-toBeUndefined' (with two 'e's).

error ESLint: Failed to load plugin 'jasmine' declared in '.eslintrc': Cannot find module 'eslint-plugin-jasmine' ↓

cause Plugin not installed or not in node_modules.

fix

Run npm install --save-dev eslint-plugin-jasmine. Ensure you're in the correct project directory.

error Configuration for rule 'jasmine/no-focused-tests' is invalid: Severity should be one of the following: 0 = off, 1 = warn, 2 = error ↓

cause Rule severity set to incorrect value (e.g., string or boolean).

fix

Set rule severity to 0, 1, or 2. E.g., 'jasmine/no-focused-tests': 'error' works as well.

error Cannot read property 'globals' of undefined when using plugin.environments.jasmine in flat config ↓

cause Flat config requires importing from the plugin directly; environments might not be exported in older versions.

fix

Use plugin.languageOptions?.globals or manually set globals. Upgrade to latest version.

Warnings

breaking ESLint v9 flat config support is experimental (v4.2.0-beta). Flat config consumers must import the plugin and manually set globals or use plugin.configs.recommended with caution. ↓

fix Follow flat config example in README. Use stable v4.1.x if not ready for betas.

deprecated Rule 'jasmine/valid-expect' is deprecated and will be removed in future versions. ↓

fix Remove rule from config; use built-in ESLint valid-expect or other rules.

gotcha The plugin does not automatically enable the Jasmine environment. You must set env: { jasmine: true } in .eslintrc or configure globals manually in flat config. ↓

fix Add env: { jasmine: true } in your ESLint config.

gotcha Rule 'jasmine/expect-single-argument' may report false positives when using no matcher (e.g., expect(something)). Fixed in v4.2.2 but still tricky when using nothing. ↓

fix Upgrade to v4.2.2 or configure rule to allow no arguments.

gotcha In v4.2.0, rules were refactored to export an object with a 'create' method. Custom rule implementations relying on old format may break. ↓

fix Update custom rules to follow ESLint rule format: module.exports = { meta: {...}, create(context) { return {...} } }.

Install

npm install eslint-plugin-jasmine

yarn add eslint-plugin-jasmine

pnpm add eslint-plugin-jasmine

Imports

plugin

wrong

using require('eslint-plugin-jasmine') without default import in ESM projects

correct

import plugin from 'eslint-plugin-jasmine'; or use as 'jasmine' in .eslintrc plugins array

Plugin is exported as CommonJS default. In ESLint flat config (v9+), you must import and spread plugin.configs.recommended or plugin.rules.

recommended config

wrong

using 'jasmine/recommended' without 'plugin:' prefix in older ESLint versions

correct

extends: 'plugin:jasmine/recommended' in .eslintrc or import { recommended } from 'eslint-plugin-jasmine' in flat config

The recommended config sets rules as shown in the README. For flat config: import plugin from 'eslint-plugin-jasmine'; export default [...plugin.configs.recommended];

env
wrong
```
assuming plugin automatically sets the Jasmine globals without env
```
correct
```
env: { jasmine: true } in .eslintrc or environments: { jasmine: true } in flat config
```
ESLint provides a separate Jasmine environment for globals like describe/it/expect. This plugin alone does not add those globals. Must be set explicitly.

Quickstart

Demonstrates how to set up eslint-plugin-jasmine using both legacy .eslintrc and flat config. Includes enabling the plugin, setting the Jasmine environment, extending the recommended config, and customizing rules.

// .eslintrc.js
module.exports = {
  plugins: ['jasmine'],
  env: { jasmine: true },
  extends: ['plugin:jasmine/recommended'],
  rules: {
    'jasmine/no-focused-tests': 'error',
    'jasmine/no-disabled-tests': 'warn',
  },
};

// For ESLint flat config (eslint.config.js)
import plugin from 'eslint-plugin-jasmine';
export default [
  {
    plugins: { jasmine: plugin },
    languageOptions: { globals: { ...plugin.environments.jasmine.globals } },
    rules: {
      ...plugin.configs.recommended.rules,
      'jasmine/no-focused-tests': 'error',
    },
  },
];