You can serialize simple data to check for equality:

data1 = {firstName: 'John', lastName: 'Smith'};
data2 = {firstName: 'Jane', lastName: 'Smith'};
JSON.stringify(data1) === JSON.stringify(data2)

This will give you something like

'{firstName:"John",lastName:"Smith"}' === '{firstName:"Jane",lastName:"Smith"}'

As a function…

function compare(a, b) {
  return JSON.stringify(a) === JSON.stringify(b);
}
compare(data1, data2);

EDIT

If you’re using chai like you say, check out http://chaijs.com/api/bdd/#equal-section

EDIT 2

If you just want to check keys…

function compareKeys(a, b) {
  var aKeys = Object.keys(a).sort();
  var bKeys = Object.keys(b).sort();
  return JSON.stringify(aKeys) === JSON.stringify(bKeys);
}

should do it.