eslint-plugin-inferno

eslint-plugin-inferno

Note: This is a fork of the great eslint-plugin-react.

Inferno specific linting rules for ESLint. Linting logic has been optimized for InfernoJS library. Some of the rules has been removed because they don't work in context of InfernoJS. Please see [not supported rules] section.

This plugins support NodeJS v20+, eslint v8+ and Inferno v6+ Legacy versions of nodejs and eslint are not supported to reduce code complexity

Installation

Install eslint either locally or globally. (Note that locally, per project, is strongly preferred)

$ npm install eslint@7 --save-dev

It is also possible to install ESLint globally rather than locally (using npm install -g eslint). However, this is not recommended, and any plugins or shareable configs that you use must be installed locally in either case.

Configuration (Eslint v9)

Flat Configs

This plugin exports 3 flat configs:

• flat.all
• flat.recommended

The flat configs are available via the root plugin import. They will configure the plugin under the inferno/ namespace and enable JSX in languageOptions.parserOptions.

const infernoPlugin = require('eslint-plugin-inferno');

module.exports = [
  …
  infernoPlugin.configs.flat.recommended, // This is not a plugin object, but a shareable config object
  …
];

You can of course add/override some properties.

Note: Our shareable configs does not preconfigure files or languageOptions.globals. For most of the cases, you probably want to configure some properties by yourself.

const infernoPlugin = require('eslint-plugin-inferno');
const globals = require('globals');

module.exports = [
  …
  {
    files: ['**/*.{js,mjs,cjs,jsx,mjsx,ts,tsx,mtsx}'],
    ...infernoPlugin.configs.flat.recommended,
    languageOptions: {
      ...infernoPlugin.configs.flat.recommended.languageOptions,
      globals: {
        ...globals.serviceworker,
        ...globals.browser,
      },
    },
  },
  …
];

The above example is same as the example below, as the new config system is based on chaining.

const infernoPlugin = require('eslint-plugin-inferno');
const globals = require('globals');

module.exports = [
  …
  {
    files: ['**/*.{js,mjs,cjs,jsx,mjsx,ts,tsx,mtsx}'],
    ...infernoPlugin.configs.flat.recommended,
  },
  {
    files: ['**/*.{js,mjs,cjs,jsx,mjsx,ts,tsx,mtsx}'],
    languageOptions: {
      globals: {
        ...globals.serviceworker,
        ...globals.browser,
      },
    },
  },
  …
];

Configuration (legacy: .eslintrc*)

Use our preset to get reasonable defaults:

  "extends": [
    "eslint:recommended",
    "plugin:inferno/recommended"
  ]

You should also specify settings that will be shared across all the plugin rules. (More about eslint shared settings)

{
  "settings": {
    "inferno": {
      "createClass": "createClass", // Regex for Component Factory to use,  default to "createClass"
      "pragma": "Inferno",  // Pragma to use, default to "Inferno"
      "fragment": "Fragment",  // Fragment to use (may be a property of <pragma>), default to "Fragment"
    },
    "propWrapperFunctions": [
        // The names of any function used to wrap propTypes, e.g. `forbidExtraProps`. If this isn't set, any propTypes wrapped in a function will be skipped.
        "forbidExtraProps",
        {"property": "freeze", "object": "Object"},
        {"property": "myFavoriteWrapper"},
        // for rules that check exact prop wrappers
        {"property": "forbidExtraProps", "exact": true}
    ],
    "componentWrapperFunctions": [
        // The name of any function used to wrap components, e.g. Mobx `observer` function. If this isn't set, components wrapped by these functions will be skipped.
        "observer", // `property`
        {"property": "styled"}, // `object` is optional
        {"property": "observer", "object": "Mobx"},
        {"property": "observer", "object": "<pragma>"} // sets `object` to whatever value `settings.inferno.pragma` is set to
    ],
    "formComponents": [
      // Components used as alternatives to <form> for forms, eg. <Form endpoint={ url } />
      "CustomForm",
      {"name": "SimpleForm", "formAttribute": "endpoint"},
      {"name": "Form", "formAttribute": ["registerEndpoint", "loginEndpoint"]}, // allows specifying multiple properties if necessary
    ],
    "linkComponents": [
      // Components used as alternatives to <a> for linking, eg. <Link to={ url } />
      "Hyperlink",
      {"name": "MyLink", "linkAttribute": "to"},
      {"name": "Link", "linkAttribute": ["to", "href"]}, // allows specifying multiple properties if necessary
    ]
  }
}

If you do not use a preset you will need to specify individual rules and add extra configuration.

Add "inferno" to the plugins section.

{
  "plugins": [
    "inferno"
  ]
}

Enable JSX support.

With eslint 2+

{
  "parserOptions": {
    "ecmaFeatures": {
      "jsx": true
    }
  }
}

Enable the rules that you would like to use.

  "rules": {
    "inferno/jsx-uses-vars": "error",
  }

Shareable configs

These rules have been removed because they don't make sense in context of InfernoJS. InfernoJS does not have prop-types or UNSAFE_ -lifecycle methods.

• react/default-props-match-prop-types
• react/display-name
• react/forbid-foreign-prop-types
• react/forbid-prop-types
• react/no-deprecated
• react/no-unsafe
• react/no-unused-prop-types
• react/prop-types
• react/sort-prop-types
• react/require-default-props
• react/prefer-read-only-props
• react/style-prop-object
• react/hook-use-state
• react/prefer-read-only-props
• react/prefer-exact-props

Other useful plugins

Recommended

This plugin exports a recommended configuration that enforces Inferno good practices.

To enable this configuration use the extends property in your .eslintrc config file:

{
  "extends": ["eslint:recommended", "plugin:inferno/recommended"]
}

See eslint documentation for more information about extending configuration files.

All

This plugin also exports an all configuration that includes every available rule. This pairs well with the eslint:all rule.

{
  "plugins": [
    "inferno"
  ],
  "extends": ["eslint:all", "plugin:inferno/all"]
}

Note: These configurations will import eslint-plugin-inferno and enable JSX in parser options.

Configuration (new: eslint.config.js)

From v8.21.0, eslint announced a new config system. In the new system, .eslintrc* is no longer used. eslint.config.js would be the default config file name. In eslint v8, the legacy system (.eslintrc*) would still be supported, while in eslint v9, only the new system would be supported.

And from v8.23.0, eslint CLI starts to look up eslint.config.js. So, if your eslint is >=8.23.0, you're 100% ready to use the new config system.

You might want to check out the official blog posts,

• https://eslint.org/blog/2022/08/new-config-system-part-1/
• https://eslint.org/blog/2022/08/new-config-system-part-2/
• https://eslint.org/blog/2022/08/new-config-system-part-3/

and the official docs.

Plugin

The default export of eslint-plugin-inferno is a plugin object.

const inferno = require('eslint-plugin-inferno');
const globals = require('globals');

module.exports = [
  …
  {
    files: ['**/*.{js,jsx,mjs,cjs,ts,tsx}'],
    plugins: {
      inferno,
    },
    languageOptions: {
      parserOptions: {
        ecmaFeatures: {
          jsx: true,
        },
      },
      globals: {
        ...globals.browser,
      },
    },
    rules: {
      // ... any rules you want
      'inferno/jsx-uses-vars': 'error',
     },
    // ... others are omitted for brevity
  },
  …
];

List of supported rules

💼 Configurations enabled in.
☑️ Set in the recommended configuration.
🔧 Automatically fixable by the --fix CLI option.
💡 Manually fixable by editor suggestions.
❌ Deprecated.

Name	Description	💼	🔧	💡	❌
boolean-prop-naming	Enforces consistent naming for boolean props
button-has-type	Disallow usage of button elements without an explicit type attribute
checked-requires-onchange-or-readonly	Enforce using onChange or readonly attribute when checked is used
destructuring-assignment	Enforce consistent usage of destructuring assignment of props, state, and context		🔧
forbid-component-props	Disallow certain props on Components
forbid-dom-props	Disallow certain props on DOM Nodes
forbid-elements	Disallow certain elements
forward-ref-uses-ref	Require all forwardRef components include a ref parameter			💡
function-component-definition	Enforce a specific function type for function components		🔧
iframe-missing-sandbox	Enforce sandbox attribute on iframe elements
inferno-in-jsx-scope	Disallow missing Inferno when using JSX
jsx-boolean-value	Enforce boolean attributes notation in JSX		🔧
jsx-child-element-spacing	Enforce or disallow spaces inside of curly braces in JSX attributes and expressions
jsx-closing-bracket-location	Enforce closing bracket location in JSX		🔧
jsx-closing-tag-location	Enforce closing tag location for multiline JSX		🔧
jsx-curly-brace-presence	Disallow unnecessary JSX expressions when literals alone are sufficient or enforce JSX expressions on literals in JSX children or attributes		🔧
jsx-curly-newline	Enforce consistent linebreaks in curly braces in JSX attributes and expressions		🔧
jsx-curly-spacing	Enforce or disallow spaces inside of curly braces in JSX attributes and expressions		🔧
jsx-equals-spacing	Enforce or disallow spaces around equal signs in JSX attributes		🔧
jsx-filename-extension	Disallow file extensions that may contain JSX
jsx-first-prop-new-line	Enforce proper position of the first property in JSX		🔧
jsx-fragments	Enforce shorthand or standard form for Inferno fragments		🔧
jsx-handler-names	Enforce event handler naming conventions in JSX
jsx-indent	Enforce JSX indentation		🔧
jsx-indent-props	Enforce props indentation in JSX		🔧
jsx-key	Disallow missing key props in iterators/collection literals	☑️
jsx-max-depth	Enforce JSX maximum depth
jsx-max-props-per-line	Enforce maximum of props on a single line in JSX		🔧
jsx-newline	Require or prevent a new line after jsx elements and expressions.		🔧
jsx-no-bind	Disallow .bind() or arrow functions in JSX props
jsx-no-comment-textnodes	Disallow comments from being inserted as text nodes	☑️
jsx-no-constructed-context-values	Disallows JSX context provider values from taking values that will cause needless rerenders
jsx-no-duplicate-props	Disallow duplicate properties in JSX	☑️
jsx-no-leaked-render	Disallow problematic leaked values from being rendered		🔧
jsx-no-literals	Disallow usage of string literals in JSX
jsx-no-script-url	Disallow usage of javascript: URLs
jsx-no-target-blank	Disallow target="_blank" attribute without rel="noreferrer"	☑️	🔧
jsx-no-undef	Disallow undeclared variables in JSX	☑️
jsx-no-useless-fragment	Disallow unnecessary fragments		🔧
jsx-one-expression-per-line	Require one JSX element per line		🔧
jsx-pascal-case	Enforce PascalCase for user-defined JSX components
jsx-props-class-name	Enforce 'class' or 'className' attributes		🔧
jsx-props-no-multi-spaces	Disallow multiple spaces between inline JSX props		🔧
jsx-props-no-spread-multi	Disallow JSX prop spreading the same identifier multiple times
jsx-props-no-spreading	Disallow JSX prop spreading
jsx-sort-default-props	Enforce defaultProps declarations alphabetical sorting				❌
jsx-sort-props	Enforce props alphabetical sorting		🔧
jsx-space-before-closing	Enforce spacing before closing bracket in JSX		🔧		❌
jsx-tag-spacing	Enforce whitespace in and around the JSX opening and closing brackets		🔧
jsx-uses-vars	Disallow variables used in JSX to be incorrectly marked as unused	☑️
jsx-wrap-multilines	Disallow missing parentheses around multiline JSX		🔧
no-access-state-in-setstate	Disallow when this.state is accessed within setState
no-adjacent-inline-elements	Disallow adjacent inline elements not separated by whitespace.
no-array-index-key	Disallow usage of Array index in keys
no-arrow-function-lifecycle	Lifecycle methods should be methods on the prototype, not class fields		🔧
no-children-prop	Disallow passing of children as props	☑️
no-danger	Disallow usage of dangerous JSX properties
no-danger-with-children	Disallow when a DOM element is using both children and dangerouslySetInnerHTML	☑️
no-did-mount-set-state	Disallow usage of setState in componentDidMount
no-did-update-set-state	Disallow usage of setState in componentDidUpdate
no-direct-mutation-state	Disallow direct mutation of this.state	☑️
no-find-dom-node	Disallow usage of findDOMNode	☑️
no-invalid-html-attribute	Disallow usage of invalid attributes			💡
no-is-mounted	Disallow usage of isMounted	☑️
no-multi-comp	Disallow multiple component definition per file
no-namespace	Enforce that namespaces are not used in Inferno elements
no-object-type-as-default-prop	Disallow usage of referential-type variables as default param in functional component
no-redundant-should-component-update	Disallow usage of shouldComponentUpdate when extending Inferno.PureComponent
no-render-return-value	Disallow usage of the return value of Inferno.render	☑️
no-set-state	Disallow usage of setState
no-string-refs	Disallow using string references	☑️
no-this-in-sfc	Disallow this from being used in stateless functional components
no-typos	Disallow common typos
no-unescaped-entities	Disallow unescaped HTML entities from appearing in markup	☑️		💡
no-unknown-property	Disallow usage of unknown DOM property	☑️	🔧
no-unstable-nested-components	Disallow creating unstable components inside components
no-unused-class-component-methods	Disallow declaring unused methods of component class
no-unused-state	Disallow definitions of unused state
no-will-update-set-state	Disallow usage of setState in componentWillUpdate
prefer-es6-class	Enforce ES5 or ES6 class for Inferno Components
prefer-stateless-function	Enforce stateless components to be written as a pure function
require-optimization	Enforce Inferno components to have a shouldComponentUpdate method
require-render-return	Enforce ES5 or ES6 class for returning value in render function	☑️
self-closing-comp	Disallow extra closing tags for components without children		🔧
sort-comp	Enforce component methods order
sort-default-props	Enforce defaultProps declarations alphabetical sorting
state-in-constructor	Enforce class component state initialization style
static-property-placement	Enforces where Inferno component static properties should be positioned.
style-prop-object	Enforce style prop value is an object
void-dom-elements-no-children	Disallow void DOM elements (e.g. <img />, <br />) from receiving children

License

eslint-plugin-inferno is licensed under the MIT License.