The enhanced ecommerce plug-in for analytics.js enables the measurement of user interactions with products on ecommerce websites across the user's shopping experience, including: product impressions, product clicks, viewing product details, adding a product to a shopping cart, initiating the checkout process, transactions, and refunds.
Almost everything you need to track with analytics.js can be done using the ga() command queue. This guide explains what the command queue is, how it works, and how to execute commands to track user interactions.
Documentation Enhanced Ecommerce