I always think of weird ways to accomplish things. This approach could be applied to some functional JS.
// I really dig this one
const foo = {
bar: {
baz: [{ changeMe: 'asdf', notMe: 'asdf' }, { changeMe: 'ffff', notMe: 'asdf' }],
},
};
const newArr = foo.bar.baz.map(baz => ({ ...baz, changeMe: 'swee' }));
const newData = {
...foo,
bar: {
baz: newArr,
},
};
console.log('newData', newData.bar.baz);