Dennis Doomen

A couple of people asked me why I created (yet) another .NET HTTP mocking library. I found that hard to explain without criticizing other options, so it's something you need to try to fully understand it. The people that did, were all enthusiastic and helped me fine tune the API.

dennisdoomen.comMockly: fluent HTTP mocking for .NET like it should have been doneWhat Mockly does, how it makes testing code that uses HttpClient easier, and the features that help you test the unhappy paths as well.

To get you started, I decided to write an extensive blog post. So either take Mockly for a spin or read www.dennisdoomen.com/2026/10/mock... and let me know what you think.

PackageGuard 2.11 blocks packages that OSV lists as malware, whatever their risk score. It also ranks vulnerabilities with CISA KEV and EPSS exploit data. A new setting accepts a known vulnerability, with a reason. packageguard.org

PackageGuard 2.10.0 is out. The new command "dependencies" finds NuGet package references you may not need, and packages that resolve to different versions. Also: vulnerable packages first in the HTML report, and fairer risk scores. packageguard.org/docs/depende...

Treat the results as candidates. The command reads the restore graph, so it cannot see what your code uses directly. Some packages now score lower after scoring fixes. Check risk exceptions tuned to old scores. Thanks to Chrison Simtian for the command.

Hey @github.com, why did you remove the next/previous options in the new PR experience?

A week with more architecture and meetings than coding is clearly visible in my Claude usage. I've only used 38% of my weekly budget.

PackageGuard 2.8 adds gated policies so you can prevent your builds from succeeding based on a various quality, operation and security attributes. Read all about that at www.dennisdoomen.com/2026/09/pack...

Few conferences leave such a lasting impression as Techorama does, so I'm happy that, again, I'm playing a small part in their impressive line-up. To celebrate that, I can offer you a discount of 100 euros through tickets.techorama.nl/2026/redeem?... Will I see you there?

17 Sept

v2.7 of PackageGuard makes it easy to figure out why your codebase is using a specific NuGet or NPM package. It will show where in your project a particular package is used, which version was resolved and risks exists. Learn more about this at packageguard.org/docs/explain

15 Sept

Tomorrow, I'll be travelling to Oslo to speak at the renowned @ndcconferences.com. Although this is my 7th NDC, I remain humbled to be at the one that started it all. Will I see you there?

14 Sept

This evening, we've released Fluent Assertions 8.11. Check out the detailed release notes at github.com/fluentassert... #mvpbuzz #unittesting #assertions

10 Sept

PackageGuard, the fully open-source alternative to tools like Snyk, Black Duck and others, has just received an update that improves the risk report by removing overlapping risk factors and include all the vulnerabilities details. Also check out the new website at packageguard.org

9 Sept

Mockly, the open-source HTTP mocking library for .NET is getting better and better. Check out some of the newest features that got released over the weekend in the image below, or read the docs at mockly.org/docs/advance...

8 Sept

Pathy, the source-only .NET library that makes working with files and directories a very fluent experience, received a new version. Check it out at github.com/dennisdoomen...

7 Sept

Reflectify, a source-only open-source package with tons of Reflection smartness, got a new release. Check out the release notes at github.com/dennisdoomen... #mvpbuzz #dotnet #csharp #oss

7 Sept

When should a C# operation be a method rather than a property? Use a method if it’s expensive, performs a conversion, returns a different result each call, or causes side effects. Lazy-loading and internal caching are reasonable exceptions. #csharp #codingguidelines #codingconventions

4 Sept

My weekly Claude Team limit got reset halfway the week and will reset again tomorrow. Did that happen to anybody else?

31 Aug

Properties should be stateless with respect to other properties. Setting DataSource then DataMember should have the same result as the reverse. Sounds trivial, but I've seen plenty of classes where properties were anything but simple. #csharp #codingguidelines #classdesign #codingconventions

31 Aug

I've just burned through my 5-hour limit and 13% of my weekly limit in 38 minutes and I don't even understand what happened. Using Cloud Team and Sonnet 5.

27 Aug

PackageGuard, your totally free NuGet/NPM package scanning and risk reporting tool now supports generating a Software Bill Of Materials (SBom) in CycloneDX and SPDX format. Check out the documentation at github.com/dennisdoomen... Stay tuned for even more awesome features soon...

youtube.comThe Witcher 3: Wild Hunt — Remastered | Official Announcement TrailerYouTube video by The Witcher

27 Aug

I always had a wish to replay "The Witcher 3", but that has now become a definitive plan.... www.youtube.com/watch?v=IGk1...

25 Aug

Over the weekend, I've released Reflectify 1.10, a NuGet package that replaces all that hand-rolled Reflection code with battle-tested extension methods. Check out the release notes at github.com/dennisdoomen...

25 Aug

💡And for those that are concerned about the dependency hell. Reflectify ships as a source-only package. In other words, it compiles the code into your project without any visible binary dependencies.

25 Aug

I love this new description of the term IDE in the age of AI #dotnetdaych

20 Aug

Looking forward to my first real .NET conference in Switzerland. And let's start the conference season on a high note with two talks in the same day. Will I see you there? #mvpbuzz #dotnetdaych

17 Aug

During the weekend, I've released Mockly 1.11, the new in-memory HTTP mocking library in town. This version allows you to simulate delayed responses or requests that throw exceptions. Check out the docs at mockly.org

youtube.comThe Actors Roundtable | 25th Anniversary 'Band of Brothers' SymposiumYouTube video by The National WWII Museum

17 Aug

If you love Band of Brothers like me and remember every scene episode by episode, check out this amazing reunion. www.youtube.com/watch?v=xMaM...

10 Aug

An interface with one method is often just a named function signature. If it is not likely to grow, a delegate is simpler, more loosely coupled, and easier to test.

10 Aug

Prefer a single-method interface when state matters, the contract is strong (IDisposable, IEquatable), default interface methods help, or more members are likely soon. #codingstandards #csharp #codingguidelines #designpractices #bestpractices

csharpcodingguidelines.comIntroductionfor all C# versions up to v14

Want to learn more about high-quality software development? Check out csharpcodingguidelines.com

12 Aug

C# 12 primary constructors reduce boilerplate when capturing dependencies. Prefer when: ✅ Constructor only captures dependencies/config ✅ No complex initialization Avoid when: ✅ Validation or non-trivial initialization is needed #csharp #codingguidelines #classdesign

csharpcodingguidelines.comIntroductionfor all C# versions up to v14

Want to learn more about high-quality software development? Check out csharpcodingguidelines.com

13 Aug

We released Fallout 10.4—the first new version since Nuke was abandoned. Fallout replaces messy YAML pipelines with refactorable, debuggable, navigable C#. • Inspired by Make • Makes Azure DevOps → GitHub Actions migration easier • Used in my OSS & client projects

docs.fallout.buildFalloutBuild automation for C#/.NET — the hard-fork successor to NUKE

Check it out at docs.fallout.build

The 2026-2027 MVP ring has finally made it from the US. #mvpbuzz

5 Aug

Choosing between records and classes in C# matters! Records: data-focused, immutable, structural equality (DTOs, value objects) Classes: behavior-focused, mutable state, identity-based Record struct: small immutable values (stack allocation) Mix them and you've got a design problem. #CSharp

csharpcodingguidelines.comIntroductionfor all C# versions up to v14

6 Aug

Want to learn more about high-quality software development? Check out csharpcodingguidelines.com

4 Aug

In general, if you find a lot of data-only classes in your code base, you probably also have a few (static) classes with a lot of behavior. Use the principles of object-orientation explained and move the logic close to the data it applies to. ⚠️The only exceptions to this rule are classes...

4 Aug

...that are used to transfer data over a communication channel, also called Data Transfer Objects, or a class that wraps several parameters of a method. For DTOs, consider using an immutable record type instead of a class to make the intent explicit. #csharp #codingguidelines #classdesign #

5 Aug

Want to learn more about high-quality software development? Check out csharpcodingguidelines.com

If you find yourself writing code like this someObject.SomeProperty.GetChild().Foo() ...then you may be violating the Law of Demeter. An object should not expose other classes it depends on, because callers may misuse that exposed property or method to access the object behind it...

By doing so, calling code becomes coupled to the underlying class you're using, making it harder to replace or refactor later. 💡 Fluent Interfaces may look like a violation, but they're simply returning themselves to enable method chaining, so they don't break the intent of the rule...

💡 Inversion of Control or Dependency Injection frameworks sometimes require exposing a dependency as a public property. If it's only used for dependency injection and nothing else, I wouldn't consider that a violation. #bestpractices #codingdesign #codingguidelines #csharp

23 July

In other words, you should be able to pass an instance of a derived class wherever its base class is expected, without the callee knowing the derived class. A very notorious example of a violation of this rule is throwing a NotImplementedException when overriding methods from a base...

23 July

...class. A less subtle example is not honoring the behavior expected by the base class. #bestpractices #codingdesign #codingguidelines #csharp

Want to learn more about high-quality software development? Check out csharpcodingguidelines.com

21 July

Did you know there's a great way to start building an (open-source) library in .NET that comes with everything you'd expect from a professional package? And did you know it supports GitHub and Azure DevOps? If not, check out github.com/dennisdoomen.... Version 1.9 was released over the weekend.

16 July

✅7 done 🎤5 to go Hope to see you after the summer... #mvpbuzz