Book Image

Practical Test-Driven Development using C# 7

By : John Callaway, Clayton Hunt
Book Image

Practical Test-Driven Development using C# 7

By: John Callaway, Clayton Hunt

Overview of this book

Test-Driven Development (TDD) is a methodology that helps you to write as little as code as possible to satisfy software requirements, and ensures that what you've written does what it's supposed to do. If you're looking for a practical resource on Test-Driven Development this is the book for you. You've found a practical end-to-end guide that will help you implement Test-Driven Techniques for your software development projects. You will learn from industry standard patterns and practices, and shift from a conventional approach to a modern and efficient software testing approach in C# and JavaScript. This book starts with the basics of TDD and the components of a simple unit test. Then we look at setting up the testing framework so that you can easily run your tests in your development environment. You will then see the importance of defining and testing boundaries, abstracting away third-party code (including the .NET Framework), and working with different types of test double such as spies, mocks, and fakes. Moving on, you will learn how to think like a TDD developer when it comes to application development. Next, you'll focus on writing tests for new/changing requirements and covering newly discovered bugs, along with how to test JavaScript applications and perform integration testing. You’ll also learn how to identify code that is inherently un-testable, and identify some of the major problems with legacy applications that weren’t written with testability in mind. By the end of the book, you’ll have all the TDD skills you'll need and you’ll be able to re-enter the world as a TDD expert!
Table of Contents (21 chapters)
Title Page
Packt Upsell
Foreword
Contributors
Preface
4
What to Know Before Getting Started
Index

Hello World


Stepping back to one of our first examples, take a look at the sample Hello World application. Remember that, depending on the time of day, a different message is displayed to the user. Before noon, the user is greeted with Good morning, and after noon, Good afternoon is returned to the user.

A change in requirements

Depending on the time of day, the user is greeted with Good morning or Good afternoon. To extend the functionality and introduce a new feature, let's address the user with Good evening if the time of day is between 6 p.m. and midnight.

Good evening 

In order to introduce this new feature, begin with the tests. Modification of an existing test will be needed, as well as adding one or more new tests to cover the change in requirements.

Modify the Theory data provided to GivenAfternoon_ThenAfternoonMessage so that only noon through 6 p.m. are included for this test. Now, create a new test method, GivenEvening_ThenEveningMessage:

[Theory]
[InlineData(19)]
[InlineData(20)]...