Defers invoking a function until the current call stack has cleared.

Use setTimeout() with a timeout of 1ms to add a new event to the browser event queue and allow the rendering engine to complete its work. Use the spread (...) operator to supply the function with an arbitrary number of arguments.


const defer = (fn, ...args) => setTimeout(fn, 1, ...args);


// Example A:
defer(console.log, 'a'), console.log('b'); // logs 'b' then 'a'

// Example B:
document.querySelector('#someElement').innerHTML = 'Hello';
longRunningFunction(); // Browser will not update the HTML until this has finished
defer(longRunningFunction); // Browser will update the HTML then run the function