Tools and Practices

Debugging, unit testing, benchmarking, and clean code principles for writing higher-quality, maintainable software.

Tools and Practices

Writing code is only part of the job; creating quality software requires testing, debugging, and performance measurement. This section covers Visual Studio tips, writing tests with xUnit/NUnit, measuring performance with BenchmarkDotNet, and applying Clean Code principles.

It also covers practical topics such as making API calls with HttpClient and mocking dependencies using Moq.

TL;DR

Debugging: breakpoints, watch windows.
Testing: xUnit, Moq, FluentValidation.
Clean Code + layered architecture.

Debugging Techniques in C#

20 April 2026 • Tools and Practices

Learn debugging techniques in C# using breakpoints, watch windows, and step tools to quickly identify and fix issues.

C# Debugging

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Visual Studio / VS Code Tips for C#

20 April 2026 • Tools and Practices

Learn Visual Studio and VS Code tips for C# to improve productivity with shortcuts, extensions, and efficient workflows.

C# Visual Studio VS Code

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Writing Unit Tests in C# (xUnit, NUnit, MSTest)

20 April 2026 • Tools and Practices

Learn how to write unit tests in C# using xUnit, NUnit, and MSTest to build reliable and maintainable applications.

C# NUnit Testing xUnit

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In C#, const values are fixed at compile time, while readonly values can be assigned at runtime, usually in the constructor.


// const: value must be known at compile time
public const int MaxItems = 10;

// readonly: value can be set at runtime
public readonly int Timeout;

public Settings()
{
    Timeout = GetTimeoutFromConfig();
}

In C#, the ?. operator allows you to safely access a property or method. If the object has no value (null), the result is also null and no error occurs.


Person? person = null;

// Old approach
string name1 = person != null ? person.Name : null;

// Recommended approach
string? name2 = person?.Name;

Console.WriteLine(name1); // null
Console.WriteLine(name2); // null

In C#, modifying a collection inside a foreach loop causes runtime errors. If you need to change the collection, iterate over a copy or use a different loop.


// This will cause an error
foreach (var item in items)
{
    items.Remove(item);
}

// Safe approach: iterate over a copy
foreach (var item in items.ToList())
{
    items.Remove(item);
}

// Alternative: use for loop
for (int i = items.Count - 1; i >= 0; i--)
{
    items.RemoveAt(i);
}

In C#, use class when objects are identified by who they are. Use record when objects are identified by their values.


// class: identity-based
class User
{
    public string Name { get; set; }
    public int Age { get; set; }
}

var u1 = new User { Name = "Alice", Age = 30 };
var u2 = new User { Name = "Alice", Age = 30 };

Console.WriteLine(u1 == u2); // False


// record: value-based
record UserRecord(string Name, int Age);

var r1 = new UserRecord("Alice", 30);
var r2 = new UserRecord("Alice", 30);

Console.WriteLine(r1 == r2); // True

In C#, nameof() returns the name of a variable, property, or method as text. This helps prevent errors caused by hard-coded strings.


int age = 25;

// Old approach
if (age < 0)
{
    throw new ArgumentException("age");
}

// Recommended approach
if (age < 0)
{
    throw new ArgumentException(nameof(age));
}

Console.WriteLine(nameof(age)); // age