How to remove an item from object without mutating it

removeItemFromObject.js

// To remove an item from an array by id:

return state.filter(item => item.id !== action.id)
// To remove a key from an object by id:

let copy = Object.assign({}, state) // assuming you use Object.assign() polyfill!
delete copy[action.id] // shallowly mutating a shallow copy is fine
return copy
// (Bonus) The same with object spread operator proposal:

let { [action.id]: deletedItem, ...rest } = state
return rest

// Source: http://stackoverflow.com/questions/35342355/remove-data-from-nested-objects-without-mutating

// We can also do the following if we have more nested items:
const {
  [queueName]: {
    [id]: {},
    ...others
  }
} = state;
return others;