import merge from 'lodash/merge' let object = { 'a': [{ 'b': 2 }, { 'd': 4 }]}; let other = { 'a': [{ 'c': 3 }, { 'e': 5 }]}; merge(object, other); // => { 'a': [{ 'b': 2, 'c': 3 }, { 'd': 4, 'e': 5 }] }