Open source contribution in C#: where to start and not go crazy

Why open source is not scary, but beneficial?

Many developers, especially in C#, look at open source with caution. It seems that only gurus are there, just waiting to criticize your code. In fact, open source contribution is the best way to level up your skills, gain experience working in a large team, and make friends around the world.

I myself was afraid to make my first Pull Request for a long time. I thought: "Who am I to mess with code written by pros?". And then I just fixed a typo in the documentation — and it took off. Now I have over 50 merges in various C# projects. And I want to tell you how to start contributing to open source without unnecessary stress.

Step 1. Find your "sandbox"

Don't jump straight into the core of ASP.NET Core or Roslyn. Start small. Here are three types of projects that will welcome you with open arms:

• C# Libraries — there are thousands of them on GitHub. Search by tags csharp, dotnet, library.
• Developer Tools — code analyzers, generators, utilities.
• Documentation — yes, that's also open source. And often it has the most "gaps".

A great way to find a project is to go to GitHub and search for label:"good first issue" language:csharp. These are special labels for beginners. Such tasks are specifically marked as simple and understandable.

Step 2. Get familiar with the tools

Before writing code, make sure you have:

• Git (preferably via console, not GUI)
• Visual Studio or Rider (Community Edition will do)
• A GitHub account
• Basic understanding of git clone, git branch, git commit, git push

If you're still struggling with Git — no problem. Just fork the project, make changes through the GitHub interface, and create a Pull Request from there. This is the easiest path for the first time.

Step 3. Find a bug or feature

Let's say you've chosen a project. What to do next? Open the Issues tab and look for tasks with labels:

• good first issue
• help wanted
• beginner
• documentation

If you don't find anything — don't hesitate to write in the comments: "Hi! I'm a beginner, I want to help. Is there something simple?". Believe me, maintainers are usually very friendly. They also started once.

Step 4. Write code (with an example)

Imagine you found a bug: a string extension method does not handle the null case. Here's how it might look.

Original code (with bug):

public static class StringExtensions{    public static string Reverse(this string input)    {        char[] chars = input.ToCharArray();        Array.Reverse(chars);        return new string(chars);    }}

Your fix:

public static class StringExtensions{    public static string Reverse(this string input)    {        if (input == null)            throw new ArgumentNullException(nameof(input));

        char[] chars = input.ToCharArray();        Array.Reverse(chars);        return new string(chars);    }}

See? Nothing supernatural. Just added a null check and threw the correct exception. This is already a worthy open source contribution.

Step 5. Write unit tests

Good practice is to add tests for your code. Here's an example for our fix using xUnit:

public class StringExtensionsTests{    [Fact]    public void Reverse_ValidString_ReturnsReversed()    {        var result = "hello".Reverse();        Assert.Equal("olle