Object.assign—override nested property

Question

I have an Object a like that:

const a = {   user: {    …    groups: […]    …   } } 

whereby there are a lot more properties in a.user

And I would like to change only the a.user.groups value. If I do this:

const b = Object.assign({}, a, {   user: {     groups: {}   } }); 

b doesn't have any other Property except b.user.groups, all others are deleted. Is there any ES6 way to only change the nested property, without loosing all the other, with Object.assign?

Answer 1

After some trying I could find a solution that looks pretty nice like that:

const b = Object.assign({}, a, {   user: {     ...a.user,     groups: 'some changed value'   } }); 

To make that answer more complete here a tiny note:

const b = Object.assign({}, a) 

is essentially the same as:

const b = { ...a } 

since it just copies all the properties of a (...a) to a new Object. So the above can written as:

 const b = {    ...a,          //copy everything from a    user: {        //override the user property       ...a.user,  //same sane: copy the everything from a.user       groups: 'some changes value'  //override a.user.group    }  }