Merging states in Redux store

Sometimes I have found I have an object in my Redux store which has multiple children properties and I need to update some of the object properties but keep the rest the same i.e. I need to merge 2 states together.

If this is how our Redux store looked to start with: currentState

{
    profile: {
        title: 'Mr',
        firstName: 'Jose',
        lastName: 'Mourinho'
    }
}

And our new state was like this: changeState

{
  profile: {
      firstName: 'Ole',
      lastName: 'Solksjaer'
  }
}

To merge these states we can use the assign method. I have created a React method that returns the merge of the 2 states.

const assign = Object.assign || require('object.assign');

_mergeCurrentState(currentState, change) {
    return assign(currentState, change);
}

We can call it like this and pass it straight into our changeProfileData Redux action:

this.props.dispatch(actions.changeProfileData(
    this._mergeWithCurrentState(currentState, changeState)
));

Our changeProfileData action looks like this:

export function changeProfileData(newState) {
    return { type: 'PROFILE', newState };
}

Our reducer would look something like this:

export default function data(prevState = {}, action) {

  switch (action.type) {
  case 'PROFILE':
    return assign({}, prevState, {
      profile: action.newState
    });

  default:
    return prevState;
  }

}

Our new Redux store data would look like the following. The title hasn't changed but the 'firstName' and 'lastName' have been updated.

{
  profile: {
      title: 'Mr',
      firstName: 'Ole',
      lastName: 'Solksjaer'
  }
}