Book Image

Mastering TypeScript 3 - Third Edition

By : Nathan Rozentals
Book Image

Mastering TypeScript 3 - Third Edition

By: Nathan Rozentals

Overview of this book

TypeScript is both a language and a set of tools to generate JavaScript. It was designed by Anders Hejlsberg at Microsoft to help developers write enterprise-scale JavaScript. Starting with an introduction to the TypeScript language, before moving on to basic concepts, each section builds on previous knowledge in an incremental and easy-to-understand way. Advanced and powerful language features are all covered, including asynchronous programming techniques, decorators, and generics. This book explores many modern JavaScript and TypeScript frameworks side by side in order for the reader to learn their respective strengths and weaknesses. It will also thoroughly explore unit and integration testing for each framework. Best-of-breed applications utilize well-known design patterns in order to be scalable, maintainable, and testable. This book explores some of these object-oriented techniques and patterns, and shows real-world implementations. By the end of the book, you will have built a comprehensive, end-to-end web application to show how TypeScript language features, design patterns, and industry best practices can be brought together in a real-world scenario.
Table of Contents (16 chapters)
Free Chapter
TypeScript Tools and Framework Options

Test-driven development

Test-driven development (TDD) is really a way of thinking about our code that should be part of a standard development process. It is a development paradigm that starts with tests, and drives the momentum of a piece of production code through these tests. TDD means asking the question how do I know that I have solved the problem? instead of just how do I solve the problem? This is an important idea to grasp. We write code in order to solve a problem, but we should be able to prove that we have solved the problem through the use of automated tests.

The basic steps of a test-driven approach are the following:

  • Write a test that fails
  • Run the test to ensure that it fails
  • Write code to make the test pass
  • Run the test so see that it passes
  • Run all tests to see that the new code does not break any other
  • Repeat

Using TDD practices is really a mindset. Some developers...