@lwc/eslint-plugin-lwc

Official ESLint rules for Lightning Web Components (LWC).

Installation

$ npm install eslint babel-eslint @lwc/eslint-plugin-lwc --save-dev

Usage

Add lwc to the plugins section of your configuration. Then configure the desired rules in the rules sections. Some of the syntax used in Lightning Web Components is not yet stage 4 (eg. decorators), and the out-of-the-box parser from ESLint doesn't support this syntax yet. In order to parse the LWC files properly, set the parser field to babel-eslint.

Example of .eslintrc:

{
    "parser": "babel-eslint",
    "plugins": ["@lwc/eslint-plugin-lwc"],
    "rules": {
        "@lwc/lwc/no-deprecated": "error",
        "@lwc/lwc/valid-api": "error",
        "@lwc/lwc/no-document-query": "error"
    }
}

For more details about configuration please refer to the dedicated section in the ESLint documentation: https://eslint.org/docs/user-guide/configuring

Rules

LWC

Rule ID	Description
lwc/no-deprecated	disallow usage of deprecated LWC APIs
lwc/valid-api	validate api decorator usage
lwc/valid-track	validate track decorator usage
lwc/valid-wire	validate wire decorator usage
lwc/no-document-query	Disallow DOM query at the document level

Best practices

Rule ID	Description
lwc/no-inner-html	disallow usage of innerHTML
lwc/no-async-operation	restrict usage of async operations

Compat performance

Older browsers like IE11 run LWC in compatibility mode. For more information about browser performance, please refer to Supported Browsers in the Lightning Web Components Developer Guide.

Rule ID	Description
lwc/no-async-await	disallow usage of the async-await syntax
lwc/no-for-of	disallow usage of the for-of syntax
lwc/no-rest-parameter	disallow usage of the rest parameter syntax