Let's say I have:
let list = [{a: {b: 'foo'}}, {a: {b: 'bar'}}]
I want to end up with:
list = [{a: 'foo'}, {a: 'bar'}]
This works:
list = list.map(d => {d.a = d.a.b; return d})
But I have a bad feeling that changing the value in place is a bad idea.
Is there a cleaner way? is my solution actually valid?
It is not changing the value in place.
map method only creates a new array by applying a callback provided function for every item in the array.
The map() method creates a new array with the results of calling a provided function on every element in the calling array.
For changing the value in place you can use forEach method.
You could use Array#forEach and change the object in situ, because you need not to return a new array, while you already mutate the original object of the array.
let list = [{ a: { b: 'foo' } }, { a: { b: 'bar' } }];
list.forEach(d => d.a = d.a.b);
console.log(list);