Using Dependency Injection Containers

Explore how dependency injection containers automate object creation and configuration in .NET unit testing. Understand the role of Microsoft.Extensions.DependencyInjection in managing service lifetimes and dependencies. Learn to write loosely coupled application code that remains testable, regardless of using DI containers, and see how testing practices benefit from this design approach.

We'll cover the following...

Introduction
Brief overview of DI containers
An example of using a DI container
Implications of using DI frameworks on unit testing
Conclusion

Introduction

Using a dependency injection container, we can avoid manually implementing dependency injection. A dependency injection container is an object that knows how to instantiate and configure objects. To do this, it needs to know about the constructor arguments and the relationships between the classes.

This lesson will demonstrate that test code remains largely the same irrespective of whether the loosely coupled application code uses manual DI or a DI container.

Brief overview of DI containers

A DI container is a library that provides DI facilities. It simplifies object composition and service lifetime management by resolving and managing object dependencies.

DI containers can analyze the requested class and determine the required dependencies at runtime. There are numerous third-party DI container frameworks, in addition to Microsoft’s own. ...

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

Using Dependency Injection Containers

Introduction

Brief overview of DI containers