Unit Testing with Typescript

Refactor 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
change the design of existing code while supported by tests • change test suites to take advantage of better designs
Daniel Coleman and Max Guernsey, III
1 week · 4-6 hours per week · INTERMEDIATE

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Look inside

The company you work for wants to improve its system by adding functionality that maximizes the profitability of any given search. As the resident TypeScript developer, your task is to apply a battery of tests to support changing the design of legacy code in preparation for adding this new functionality. You’ll refactor your production code based on advice from your architecture team. Thanks to a broad test suite, you’ll be able to change your design with no worries about accidentally breaking a required behavior. The result will be a system you can test with smaller, more meaningful tests and that easily withstands future requirement changes.

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 write high-quality tests for legacy code that can withstand future requirements changes.

  • Use IntelliJ WebStorm to write and execute tests
  • Derive tests from existing code
  • Add test coverage on an as-needed basis
  • Change the design of existing code with the support of tests
  • Change test suites to take advantage of better designs


You choose the schedule and decide how much time to invest as you build your project.
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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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