Eslint-plugin-proper-tests NPM

Installation

npm install -D eslint-plugin-proper-tests

!NOTE
For @typescript-eslint v7 use version ^1.0.0 of this plugin. For @typescript-eslint v8 use version ^2.0.0 of this plugin.

Usage

Use the recommended shared config in your .eslintrc configuration file:

module.exports = {
  "extends": ["plugin:proper-tests/recommended"]
}

and you are good to go. Run ESLint and enjoy the results.

Or, alternatively, add proper-tests to the plugins section of your .eslintrc configuration file:

module.exports = {
  "plugins": ["proper-tests"],
  // ...  
}

and configure the rules one by one:

module.exports = {
  "plugins": ["proper-tests"],
  "rules": {
    "proper-tests/no-useless-matcher-to-be-defined": "error"
  }
}

This plugin uses TypeScript to provide more accurate results. To enable this, you need to configure ESLint to work with TypeScript:

module.exports = {
  "parser": "@typescript-eslint/parser",
  "parserOptions": {
    "project": true,
    "tsconfigRootDir": __dirname,
  }
}

Running rules only on test-related files

The rules provided by this plugin assume that the files they are checking are test-related. This means it's generally not suitable to include them in your top-level configuration as that applies to all files being linted which can include source files.

For .eslintrc configs you can use overrides to have ESLint apply additional rules to specific files:

module.exports = {
  "extends": ["eslint:recommended"],
  "overrides": [
    {
      "files": ["test/**"],
      "plugins": ["proper-tests"],
      "extends": ["plugin:proper-tests/recommended"],
      "rules": { "proper-tests/no-useless-matcher-to-be-defined": "off" }
    }
  ],
  "rules": {
    "indent": ["error", 2]
  }
}

Shareable configurations

Rules

💼 Configurations enabled in.\ ✅ Set in the recommended configuration.

Name	Description	💼
no-long-arrays-in-test-each	Disallow using long arrays with objects inside `test.each()` or `it.each()`. Force moving them out of the file.	✅
no-mixed-expectation-groups	Disallow mixing expectations for different variables between each other.	✅
no-useless-matcher-to-be-defined	Disallow using `.toBeDefined()` matcher when it is known that variable is always defined.	✅
no-useless-matcher-to-be-null	Disallow using `.toBeNull()` when TypeScript types conflict with it.	✅

In order to use the rules powered by TypeScript type-checking, you must be using @typescript-eslint/parser & adjust your eslint config as outlined here.