Unit Testing with Typescript

Test and Fix Bugs you own this product

This project is part of the liveProject series Unit Testing with Typescript, Jest, and WebStorm
basic TypeScript • basic Jest
skills learned
derive tests from existing bugs • use tests to drive bug fixes
Daniel Coleman and Max Guernsey, III
1 week · 6-8 hours per week · INTERMEDIATE

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Look inside

You’re a TypeScript developer for a large company that sells stock photography products to the general public, as well as to news and other media markets. Your task is to find and fix some long-term bugs in a legacy library. You’ll write a test to characterize a bug in code that controls how certain assets are selected for a special display. After you’ve determined the source of the problem, you’ll modify the test, transforming it into a bug fix. Once you’ve squashed that bug, you’ll repeat the process to tackle two additional common bugs in TypeScript applications.

This project is designed for learning purposes and is not a complete, production-ready application or solution.

book resources

When you start your liveProject, you get full access to the following books for 90 days.

project authors

Daniel Coleman

Daniel Coleman has been writing software since he was twelve years old, and has been getting paid for it for the last ten years. He quickly progressed from individual contributor to trailblazer for software design excellence, turning his teammates into fellow disciples of high quality. Dan has also worked as an embedded coach for teams, helping them perfect their craft through best practices for code design, test-driven development, behavior-driven development, and effective requirements management. He shares his thoughts on the industry and software design at agiledesign.io.

Max Guernsey, III

Max Guernsey has over twenty years of experience in software development and is currently a managing member at DevCraft LLC. He has worked on a wide range of products and technologies, including C++ class libraries, financial analysis applications, C# and Java backends, and even multi-platform video games. He is an experienced consultant and his "coaching from the keyboard" approach provides hands-on experience to learners in all aspects of modern software development.


This liveProject is for TypeScript developers who want to improve their testing skills. To begin these liveProjects you’ll need to be familiar with the following:

  • Basic TypeScript
  • Basic Jest
  • Object-oriented programming

you will learn

In this liveProject, you’ll learn to create tests that fix specific bugs and help prevent regressions.

  • Use IntelliJ WebStorm to write and execute tests
  • Derive tests from existing bugs
  • Use tests to drive bug fixes


You choose the schedule and decide how much time to invest as you build your project.
Project roadmap
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book resources
Get full access to select books for 90 days. Permanent access to excerpts from Manning products are also included, as well as references to other resources.

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