gajus / is-arrow-function

Checks if value is an arrow function object.

is-arrow-function

Checks if value is an arrow function object.

This function is used to distinguish an arrow function from a regular function.

See http://stackoverflow.com/q/34244183/368691 for a discussion regarding the best method to determine if value is an arrow function.

Use

import isArrowFunction from 'isarrowfunction';

isArrowFunction(() => {});
// true

isArrowFunction(function () {});
// false

Install

npm install isarrowfunction

is-arrow-function's Issues

Incorrect

let isRegularFunction,
    functionToString;

functionToString = Function.prototype.toString;

isRegularFunction = (fn) => {
    return functionToString.call(fn).indexOf('function') === 0;
};

let isArrowFunction = (fn) => {
    return !isRegularFunction(fn);
};

let test = () => {
    return function () {
        console.log('test');
    }
};

isArrowFunction(test); // true