Convert the output of a JavaScript generator to an array

When working with Set and Map objects, I came across an implementation detail that got a little annoying a little too fast. The entries() method of these objects returns a generator object, which is not directly usable as an array. But, more often than not, I needed the output as an array. Let's see how we can deal with this.

As mentioned in the range generator article, generators are Iterator objects under the hood. This means that we can use the spread operator (...) to convert the output of a generator function to an array.

This means we can convert the output of any generator function to an array by simply spreading it. Here's a simple function that does just that:

const generatorToArray = gen => [...gen];

const s = new Set([1, 2, 1, 3, 1, 4]);
generatorToArray(s.entries());
// [[ 1, 1 ], [ 2, 2 ], [ 3, 3 ], [ 4, 4 ]]