var diff = require('../'); var expect = require('expect.js'); var thing1 = 'this'; var thing2 = 'that'; var thing3 = 'other'; var thing4 = 'another'; var oldArray = [thing1, thing2, thing3, thing4]; var newArray = [thing1, thing2]; diff.observableDiff(oldArray, newArray, function (d) { diff.applyChange(oldArray, d); }); expect(oldArray).to.eql(newArray);