eslint-plugin-prefer-arrow
ESLint plugin to prefer arrow functions. By default, the plugin allows usage of function
as a member of an Object's prototype, but this can be changed with the property disallowPrototype
. Functions referencing this
will also be allowed. Alternatively, with the singleReturnOnly
option, this plugin only reports functions where converting to an arrow function would dramatically simplify the code.
Class methods will not produce errors unless the classPropertiesAllowed
flag is set.
This plugin will automatically fix your code using ESLint's --fix
option, as long as you use the singleReturnOnly
option.
Installation
Install the npm package
npm install -g eslint-plugin-prefer-arrow
npm install -D eslint-plugin-prefer-arrow
Add the plugin to the plugins
section and the rule to the rules
section in your .eslintrc
"plugins": [
"prefer-arrow"
],
"rules": {
"prefer-arrow/prefer-arrow-functions": [
"warn",
{
"disallowPrototype": true,
"singleReturnOnly": false,
"classPropertiesAllowed": false
}
]
}
Configuration
disallowPrototype
: If set to true, the plugin will warn if function
is used anytime. Otherwise, the plugin allows usage of function
if it is a member of an Object's prototype.singleReturnOnly
: If set to true, the plugin will only warn for function
declarations which only contain a return statement. These often look much better when declared as arrow functions without braces. Works well in conjunction with ESLint's built-in arrow-body-style set to as-needed
.classPropertiesAllowed
: If set to true, the plugin will warn about functions which could be replaced with arrow functions defined as class instance fields. Enable if you're using Babel's transform-class-properties plugin.allowStandaloneDeclarations
: If set to true, the plugin will ignore top-level function declarations (the plugin will still warn about "inner" functions, for example, function declarations inside other functions).
Autofixing
To autofix your code, simply run ESLint with the --fix
option. Note that this only works when the singleReturnOnly
option is set to true.
eslint --fix src