mapMerge

mapMerge(target, map)

Merges target object with the result of calling map function on target, creating a new object with existing keys updated.

data-first

mapMerge({ a: 1, b: 2 }, (obj) => ({ a: obj.a * 2 })); // { a: 2, b: 2 }

data-last

pipe(
    { a: 1, b: 2 },
    mapMerge((obj) => ({ a: obj.a * 2 })),
); // { a: 2, b: 2 }