I recently had the privilege of introducing frontend testing to our code base at work. With 5 engineers working on different parts of the product at any given time, it finally made sense to add automated tests. I can foresee this helping us cut down time spent on debugging and improving the overall quality of the product.
Because our frontend stack was React and Backbone, we needed a test library that can test React components. Some deliberation later, we decided to go with Jest (by Facebook and used internally at Facebook) and Enzyme (by Airbnb and also used internally at Airbnb).