illustration for JavaScript Mocking Fundamentals

JavaScript Mocking Fundamentals

Instructor

Kent C. Dodds
15m
Updated 5 years ago
5268
people completed
Bookmark
Download
RSS

When running unit tests, you don’t want to actually make network requests or charge real credit cards. That could… get expensive… and also very, very slow. So instead of running your code exactly as it would run in production, you can modify how some of your JavaScript modules and functions work during tests to avoid test unreliability (flakiness) and improve the speed of your tests. This kind of modification can come in the form of stubs, mocks, or generally: “test doubles.”

There are some great libraries and abstractions for mocking your JavaScript modules during tests. The Jest testing framework has great mocking capabilities built-in for functions as well as entire modules. To really understand how things are working though, let’s implement some of these features ourselves.

Course Content

15m • 6 lessons

    You might also like these resources:

    illustration for Introduction to Cloudflare Workers

    Introduction to Cloudflare Workers

    Kristian Freeman・36m・Course

    Become familiar with the Workers CLI wrangler that we will use to bootstrap our Worker project. From there you'll understand how a Worker receives and returns requests/Responses. We will also build this serverless function locally for development and deploy it to a custom domain.

    illustration for Create an eCommerce Store with Next.js and Stripe Checkout

    Create an eCommerce Store with Next.js and Stripe Checkout

    Colby Fayock・1h 4m・Course

    This is a practical project based look at building a working e-commerce store using modern tools and APIs. Excellent for a weekend side-project for your developer project portfolio

    illustration for Practical Git for Everyday Professional Use

    Practical Git for Everyday Professional Use

    Trevor Miller・1h・Course

    git is a critical component in the modern web developers tool box. This course is a solid introduction and goes beyond the basics with some more advanced git commands you are sure to find useful.