An ESLint Plugin to Lint and auto-fix plain Functions into Arrow Functions, in all cases where conversion would result in the same behaviour (Arrow Functions do not support this, arguments, or new.target for example).

• ☁️ Installation
• 🏓 Playground
• ⚖️ Configuration
• 🤔 Options
• 👏🏻 Credits
• 🙋🏽‍♀️ Getting Help
• 👀 Other Projects
• 🤓 Author

npm install --save-dev eslint eslint-plugin-prefer-arrow-functions

Try it yourself at ASTExplorer.net by pasting code snippets in the top left panel, the results will appear in the bottom right panel.

Add the plugin to the plugins section and the rule to the rules section in your .eslintrc. The default values for options are listed in this example.

{
  "plugins": ["prefer-arrow-functions"],
  "rules": {
    "prefer-arrow-functions/prefer-arrow-functions": [
      "warn",
      {
        "allowNamedFunctions": false,
        "classPropertiesAllowed": false,
        "disallowPrototype": false,
        "returnStyle": "unchanged",
        "singleReturnOnly": false
      }
    ]
  }
}

If set to true, the rule won't report named functions such as function foo() {}. Anonymous function such as const foo = function() {} will still be reported.

When true, functions defined as class instance fields will be converted to arrow functions when doing so would not alter or break their behaviour.

When true, functions assigned to a prototype will be converted to arrow functions when doing so would not alter or break their behaviour.

• When "implicit", arrow functions such as x => { return x; } will be converted to x => x.
• When "explicit", arrow functions such as x => x will be converted to x => { return x; }.
• When "unchanged" or not set, arrow functions will be left as they were.

When true, only function declarations which only contain a return statement will be converted. Functions containing block statements will be ignored.

This option works well in conjunction with ESLint's built-in arrow-body-style set to as-needed.

This project is a fork of https://github.com/TristonJ/eslint-plugin-prefer-arrow by Triston Jones.

Get help with issues by creating a Bug Report or discuss ideas by opening a Feature Request.

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I'm Jamie Mason from Leeds in England, I began Web Design and Development in 1999 and have been Contracting and offering Consultancy as Fold Left Ltd since 2012. Who I've worked with includes Sky Sports, Sky Bet, Sky Poker, The Premier League, William Hill, Shell, Betfair, and Football Clubs including Leeds United, Spurs, West Ham, Arsenal, and more.