lydellOverview 
Turns sync functions into Node.js-style async ones.
Inspired by node-asyncify.
var asyncify = require("simple-asyncify")
function addSync(a, b) {
if (typeof a !== "number" || typeof b !== "number") {
throw new TypeError("add requires two numbers")
}
return a + b
}
var add = asyncify(addSync)
add(1, 2, function(error, sum) {
console.log("The sum is: " + sum)
})
add(1, function(error, sum) {
console.log(error.message)
})
console.log("Let’s do some math!")
// Let’s do some math!
// The sum is: 3
// add requires two numbers
Installation
npm install simple-asyncify
var asyncify = require("simple-asyncify")
Usage
asyncify(syncFn)
Returns an async function that accepts the same arguments as syncFn plus a
callback. It runs syncFn with the arguments. If syncFn throws an error, the
callback is invoked with that error. Otherwise the callback is invoked with
null and the return value of syncFn.
setImmediate is used to make the function async.