is-arrow-function npm module to determine if a function is an ES6 arrow function or not. NOTE: Only works in Firefox at the moment. Example var isArrowFunction = require('is-arrow-function');assert(!isArrowFunction(function () {}));assert(!isArrowFunction(null));assert(isArrowFunction((a, b) => a * b));assert(isArrowFunction(() => 42));assert(isArrowFunction(x => x * x));assert(isArrowFunction(x => () => x * x)); Tests Simply clone the repo, npm install, and run npm test