How to Create an Async Function via “new Function”
One thing I love about JavaScript is that there are many ways to accomplish the same task, one such example being creating functions. There are several patterns for functions; one of the last you see used is the new Function
method:
/* new Function(arg1, arg2 (...), body) */ const myFunction = new Function('users', 'salary', 'return users * salary');
What if you want to use this new Function
method to create an async function? You need to be a bit clever, and thanks to MDN, we have an answer:
// Shim for allowing async function creation via new Function const AsyncFunction = Object.getPrototypeOf(async function(){}).constructor; // Usage const fetchPage = new AsyncFunction("url", "return await fetch(url);"); fetchPage("/").then(response => { ... });
The usage of
is super clever, as a native Object.getPrototypeOf(async function(){}).constructor
AsyncFunction
doesn't exist. I don't believe that I've ever used the new Function
pattern but that doesn't mean you don't! And now you can make them asynchronous!
fetch() is already an async function, can you change your example?