Intermediate

From Zero to Hero: Test-Driven Development in C#

Master the craft of Test-Driven Development and write better code, faster.

5h 40m Testing
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From Zero to Hero: Test-Driven Development in C#

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Test-Driven Development in C#: Write Better Code, Ship Fewer Bugs

Look, we've all been there. You push some code on Friday, feeling confident. Monday rolls around, and your inbox is filled with bug reports.

This cycle is exhausting. And unnecessary.

The truth is that most developers aren't writing bad code intentionally. We're just using approaches that made sense 10 years ago but don't cut it for today's complex applications.

That's where Test-Driven Development comes in. It's not the academic, impractical version you might have tried before. Real TDD that works for real codebases.

What you'll learn

  • Master the Red-Green-Refactor cycle and TDD fundamentals
  • Learn to handle dependencies with Test Doubles (Dummies, Stubs, Spies, Mocks, Fakes)
  • Understand different TDD styles (Detroit vs London school)
  • Practice TDD patterns like Fake It, Triangulation, and Obvious Implementation
  • Apply TDD in team environments and Agile development
  • Rescue and test Legacy Code with Approval Testing

Why most developers struggle with testing

I've worked with hundreds of C# developers, and almost everyone starts in the same place:

"I'll write tests after I finish the code... if I have time."

That time never comes. Or worse, you write tests that just confirm your code does what it already does—not what it should do.

The result? Codebases that are brittle. Teams that move slower over time. Features that take increasingly longer to ship.

What changes when you master TDD

When you flip the script and write tests first, everything changes.

Your code becomes more focused. Your interfaces get cleaner. Dependencies become explicit. And most importantly, you catch issues while they're still quick and cheap to fix.

My students consistently report:

  • Spending less time debugging
  • Faster code reviews
  • More confidence when refactoring
  • Clearer understanding of what their code should actually do

This course goes beyond the basics

This isn't just theory—it's battle-tested approaches that work on real projects.

Through practical examples and hands-on exercises, you'll learn:

  • How to apply the Red-Green-Refactor cycle effectively
  • Testing strategies for different scenarios (from simple units to complex integrations)
  • Managing dependencies with test doubles (mocks, stubs, and more)
  • Rescuing legacy code that wasn't built with testing in mind
  • Advanced TDD patterns that level up your development skills

Plus specific techniques for making TDD work in team environments where not everyone is on board yet.

Learn TDD through real code, not slides

Theory doesn't make you better. Practice does.

That's why this course focuses on real coding examples. You'll see TDD applied to actual C# code, facing the same challenges you deal with daily.

By the end, you'll have both the mindset and practical skills to make TDD part of your development workflow.

Frequently Asked Questions

What is the target audience for this course?
This course is designed for C# developers who want to master Test-Driven Development. It's ideal for developers who are either new to TDD or have tried it before but struggled to make it work in real projects.
Do I need any prior experience to take this course?
You should have intermediate-level C# experience and basic understanding of unit testing concepts. You don't need prior TDD experience, but familiarity with writing basic unit tests will help.
What testing frameworks will we use?
We'll primarily use xUnit.NET, along with popular tools like NSubstitute, Testcontainers and FluentAssertions. However, the principles you'll learn can be applied with any testing framework.
Can I apply TDD to legacy code?
Yes! We have a dedicated section on applying TDD to existing codebases. You'll learn techniques for gradually introducing tests to legacy code without having to rewrite everything.
What if I get stuck or have questions?
The course includes detailed explanations. Plus, you get access to our community, where you can ask questions and share experiences with other students. In any case, you can always reach out to me.

Master Test-Driven Development

Write better code, ship with confidence

One-time payment • Lifetime access

Everything you need to succeed:

5h 40m of video content
Downloadable resources
Certificate of completion
Lifetime access to all updates
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