Refactoring the Primitive Obsession code smell

The Primitive Obsession code smell refers to code that is using primitive types (ex: int, bool) instead of classes and enums. This defeats one of the benefits of object-oriented programming: encapsulation. Code Smell: Primitive Obsession. Definition: Using primitives instead of encapsulating them with a class. Solution: Encapsulate the primitive fields: Move them to a new … Read more

Refactoring the Large Class code smell

The Large Class code smells refers to a class that has too many responsibilities. It’s doing too much. Ideally a class should only have one responsibility (Single Responsibility Principle). Code Smell: Large Class Definition: A class has too many responsibilities. Solution: Identify all of the distinct responsibilities of the Large Class. For each responsibility, extract … Read more

How to refactor code that has no tests using the Golden Master technique

The number one rule when refactoring is to always have tests in place before you start refactoring. Without tests, refactoring becomes a risky endeavor. Code that doesn’t have tests is often not designed to be testable. In order to make the code testable, you have to refactor it. See how this seems like an impossible … Read more

Refactoring the Long Method code smell

In this article I’ll be walking through an example of how to refactor the Long Method code smell. Code Smell: Long Method Definition: A method has too many lines of code, making it hard to understand. Solution: Extract duplicate code into a new method Extract code into smaller methods Long Method code smell example Here’s … Read more

Solving whiteboard problems to prepare for coding interviews

Companies like to ask you to solve whiteboard problems during coding interviews. If it’s an in-person interview, they’ll ask you to solve the problem on a physical whiteboard. If it’s a remote interview, they’ll either have you solve the problem on a website like HackerRank, or they’ll ask you the question in a “digital whiteboard” … Read more

How to mock static methods

The need to mock static methods in order to add a unit test is a very common problem. It’s often the case that these static methods are in third-party libraries. There are many utility libraries that are completely made up of static methods. While this makes them very easy to use, it makes them really … Read more

Event-driven .NET: Concurrent Producer/Consumer using BlockingCollection

With the Producer/Consumer pattern you have one or more threads producing new work and enqueuing it, and one or more threads consuming that work by dequeuing it and processing it. The consumers and producers share access to the work queue. Think of it like the Post Office. You have one or more people (producers) dropping … Read more

Event-driven .NET: How to add an event to a class

In the previous article we saw how events work. In this article I’ll show how to add an event to a class. In order to illustrate this I’ve created a simple chat app that uses an in-memory message queue. Each chat window is subscribed to the message queue’s OnMessageReceived event, and updates their UI upon … Read more

Event-driven .NET: how events work

The very basis of event-driven programming is the concept of events. Events are an implementation of the Observer Pattern. With the Observer Pattern you have an observable entity and entities that want to observe that entity. Objects with events are observable, and other objects subscribe to those events and are notified when the events happen. … Read more