In Place Array Replacement

Because there is no chance of not losing track of a replaced object, a complete replacement has to be done differently.

var accounts = [/* values */]

Empty and Refill the Array

accounts.splice(0, accounts.length);
data.accounts.forEach(account => {
    accounts.push(account);
});

Extract to a generic function:

function replaceArray(array, newArray) {
    array.splice(0, array.length);
    newArray.forEach(item => {
        array.push(item);
    });
}

replaceArray(accounts, data.accounts)

Using the Spread Syntax

It can be simplified by using the spread syntax:

accounts.splice(0, accounts.length, ...data.accounts);