External Dependencies and Their Challenges

Understand the challenges external dependencies bring to unit testing, especially when tightly coupled. Learn how to use dependency injection and mocks to create loosely coupled classes that enable reliable and controlled unit tests. This lesson helps you manage dependencies effectively to write maintainable and testable code.

We'll cover the following...

Introduction
Dependency example
Tightly and loosely coupled dependencies
Why are tightly coupled dependencies a challenge?
Why do tightly coupled dependencies complicate unit testing?
Conclusion

Introduction

A dependency is a class or object that another class or object relies on. In object-oriented languages, the application code consists of classes where some classes rely on other classes. In this context, relying means that one class is referenced in the other class code. It could be included in any of its method parameters, its method return types, or even in any of its method implementations. This concept is shown below where Class A depends on Class B. In this context, Class B is a ...

1.Fundamentals of Unit Testing

2.Testing Conditions With Classic And Fluent Assertions

3.Making Unit Testing More Effective

4.Unit Testing Code with External Dependencies

5.Conclusion

6.Appendix - Unit Test Project Organization and Console Setup

External Dependencies and Their Challenges

Introduction