FluentAssertions 8.10 delivers four high-impact BeEquivalentTo upgrades: null-as-empty equivalency options better extraneous-item diagnostics faster unordered matching and clearer failures for invalid path-based rules. View Full Release Notes: zurl.co/QVXK3

> "reddit" > Me: "No, you didn't". --- I haven't used FluentAssertions in years. All I remember is that it was too much work for something I could just make myself with a couple extension methods, regexes, or whatever. Update: checked the docs, and YUP.

We did this earlier this year, but I was overdue for a blog post / video on it. We removed FluentAssertions from all of Akka .NET's public TestKit packages earlier this year in response to their license change. I don't begrudge OSS maintainers for trying to get paid for their work, but my specific vision for @AkkaDotNET is that it acts as a stable foundation for building the world's most important software. I believe that in order to do that Akka .NET must be permissionless to use. I explain in the video / blog post below how, even with FOSS exceptions to commercial licenses, these types of dependencies conflict with our mission.

New video / blog post: "Why We Removed FluentAssertions from @AkkaDotNET " Akka .NET 1.5.64 removed FluentAssertions from every TestKit package. FA went commercial, and we were the 2nd-largest consumer of it on NuGet. No shade. But we won't hand a commercial dependency to every Akka .NET user. Akka .NET stays free permissionless. Here's why: youtube.com/watch?v=id4yJBe4…

Hey, #dotnet people! I want to share with you the project I built last year. SharpAssert provides rich assertion diagnostics with zero syntax ceremony, unlike rivals like FluentAssertions or built-in NUnit assertions. And it’s free and will stay free forever (unlike infamous FluentAssertions library). It’s truly unique of a kind. This is how you do evals for real! Give it a shot! github.com/yevhen/sharp.asse…

4️⃣ 𝗙𝗹𝘂𝗲𝗻𝘁𝗔𝘀𝘀𝗲𝗿𝘁𝗶𝗼𝗻𝘀 Now has a paid license for commercial use. 👉 Better choice: Shouldly or xUnit assertions 5️⃣ 𝗥𝗲𝘀𝘁𝗦𝗵𝗮𝗿𝗽 Has become outdated and less intuitive compared to modern HTTP clients. 👉 Better choice: Refit 6️⃣ 𝗔𝘂𝘁𝗼𝗙𝗮𝗰 Outdated DI container adding unnecessary complexity. 👉 Better choice: Microsoft DI 7️⃣ 𝗡𝗦𝗲𝗿𝘃𝗶𝗰𝗲𝗕𝘂𝘀 Expensive licensing model in production and complex setup. 👉 Better choice: MassTransit, Wolverine

𝗜 𝗿𝗮𝗻𝗸𝗲𝗱 𝟰𝟬 𝗡𝘂𝗚𝗲𝘁 𝗽𝗮𝗰𝗸𝗮𝗴𝗲𝘀 𝗶𝗻 .𝗡𝗘𝗧. 𝗦𝗼𝗺𝗲 𝗱𝗲𝘃𝘀 𝘄𝗶𝗹𝗹 𝗵𝗮𝘁𝗲 𝗺𝗲 𝗳𝗼𝗿 𝘁𝗵𝗶𝘀. After 12 years of building production .NET apps, here's my honest NuGet package tier list: 🏆 𝗦-𝗧𝗶𝗲𝗿: 𝗠𝘂𝘀𝘁-𝗛𝗮𝘃𝗲 𝗣𝗮𝗰𝗸𝗮𝗴𝗲𝘀 These belong in almost every .NET project. No debate. → Entity Framework Core: the ORM that does it all → Dapper: when you need raw SQL speed → Serilog: structured logging done right → FluentValidation: clean, readable validation rules → xUnit: the standard for .NET testing → Polly: resilience and retry policies made easy → StackExchange.Redis: battle-tested Redis client → SignalR: real-time communication, built-in → Dapr: powerful distributed app building blocks → Scalar: modern, beautiful API documentation ⭐ 𝗔-𝗧𝗶𝗲𝗿: 𝗘𝘅𝗰𝗲𝗹𝗹𝗲𝗻𝘁 𝗣𝗮𝗰𝗸𝗮𝗴𝗲𝘀 Solid choices that solve real problems well. → MassTransit / Wolverine: messaging done properly → Refit: typed HTTP clients with zero boilerplate → HotChocolate GraphQL: best GraphQL library for .NET → OpenTelemetry .NET: observability you actually need → TestContainers: integration tests with real databases → Moq: mocking that just works → Bogus: realistic fake data in seconds → Quartz .NET / TickerQ: job scheduling that scales → NBomber: load testing for your APIs → MailKit: the right way to send emails → Newtonsoft(.)Json: still relevant, still reliable → Swagger / Swashbuckle: classic API documentation 🔧 𝗕-𝗧𝗶𝗲𝗿: 𝗚𝗼𝗼𝗱, 𝗕𝘂𝘁 𝗦𝗶𝘁𝘂𝗮𝘁𝗶𝗼𝗻𝗮𝗹 Useful when you need them. Not for every project. → MediatR: great for CQRS, but adds indirection you may not need → Hangfire: background jobs with a dashboard UI → Mapperly: fast source-generated mapping → Scrutor: decorator pattern made easy in DI → BenchmarkDotNet: micro-benchmarking your code properly → Humanizer: string and date formatting for humans → ImageSharp: image processing without native dependencies → NetArchTest: enforce architecture rules inside tests → CsvHelper, NodaTime, Carter, Respawn, WireMock(.)Net 🟡 𝗖-𝗧𝗶𝗲𝗿: 𝗪𝗼𝗿𝗸𝘀, 𝗕𝘂𝘁 𝗕𝗲𝘁𝘁𝗲𝗿 𝗔𝗹𝘁𝗲𝗿𝗻𝗮𝘁𝗶𝘃𝗲𝘀 𝗘𝘅𝗶𝘀𝘁 They do the job. I just reach for something else first. → NLog: Serilog does it better → Rebus: MassTransit and Wolverine are stronger choices → Coravel: fine for tiny apps, limited as you grow → CliWrap, Verify, UnitsNet: niche use cases ❌ 𝗗-𝗧𝗶𝗲𝗿: 𝗔𝘃𝗼𝗶𝗱 𝗶𝗻 𝗡𝗲𝘄 𝗣𝗿𝗼𝗷𝗲𝗰𝘁𝘀 → AutoMapper, Mapster: manual mapping is cleaner, faster, and easier to debug → FluentAssertions: great library, but v7 is paid This is just my opinion based on my experience. Your project context always matters. Don't install packages to feel productive. Install them because they solve a real problem. Which package on this list do you disagree with the most? —— ♻️ Repost to help others choose the right NuGet packages ➕ Follow me ( @AntonMartyniuk ) to improve your .NET and Architecture Skills 📌 Save this post for future reference!

Developers who say they don't have time for tests Are lying. Seriosly 👇 Many .NET developers write code for months without a single test. Most say - I don't have time or a budget for tests But in the age of AI... It's never been easier and faster to write any kind of tests. You need to have a good template for your tests. And the AI will follow. ⚠️So, no more excuses for not writing tests. I created a 2026 Testing Cheatsheet that covers everything you need. Save this post. You will thank me later. 📌 Testing Frameworks • xUnit • TUnit • NUnit 📌 Assertions • xUnit Assertions • Shouldly • FluentAssertions (is now paid) 📌 Integration Testing • Testing with .NET Aspire • WebApplicationFactory TestContainers • Respawn 📌 Frontend Testing • Playwright • Selenium 📌 Mocking • NSubstitute • Moq 📌 Fake Data • Bogus • AutoFixture 📌 Snapshot Testing • Verify 📌 Behaviour Testing • ReqNRoll • SpecFlow (not maintained anymore) 📌 Performance Testing • BenchmarkDotNet • k6 • NBomber (paid for commercial usage) • JMeter Here is what I recommend in 2026: ✅ xUnit remains the most popular testing framework ✅ TUnit is a modern alternative worth exploring ✅ Shouldly is my go-to for readable assertions ✅ NSubstitute has the cleanest mocking API ✅ Bogus makes generating fake data easy ✅ Aspire provides the easiest way to write integration tests ✅ TestContainers spins up real databases in your tests ✅ Respawn resets your database between integration tests ✅ Playwright is the best choice for frontend testing today ✅ BenchmarkDotNet is the standard for micro-benchmarking in .NET ✅ k6 is excellent for load testing APIs ✅ NBomber allows you to reuse existing C# code for load tests ❌ Avoid **SpecFlow** → it is no longer maintained ❌ Be aware **FluentAssertions** is now a paid library 👉 You don't need every tool on this list. Here is your plan for adopting tests: 1. Unit Tests 2. Integration tests. 3. Load (performance) tests 4. Frontend (E2E) tests 📌 I have created a free guide for you on integration testing in Aspire: antondevtips.com/blog/dotnet… Which testing tools are you using in 2026? Share in the comments 👇 —— ♻️ Repost to help other .NET developers write better tests ➕ Follow me ( @AntonMartyniuk ) to improve your .NET and Architecture Skills

𝟭𝟱 .𝗡𝗘𝗧 𝘁𝗼𝗼𝗹𝘀 & 𝗹𝗶𝗯𝗿𝗮𝗿𝗶𝗲𝘀 𝘁𝗵𝗲 𝗰𝗼𝗺𝗺𝘂𝗻𝗶𝘁𝘆 𝗮𝗰𝘁𝘂𝗮𝗹𝗹𝘆 𝘂𝘀𝗲𝘀 I asked r/dotnet one question: which .NET libraries do you actually use that nobody talks about? The thread got hundreds of replies. I filtered for the ones with 10 upvotes. CSharpier got 62 votes. Refit was second. Then a bunch of tools sitting between 30–31 votes, most of which most developers either don't know or never mention in tutorials. A few things stood out to me: The community is now skeptical of dependencies. FluentAssertions, IdentityServer, and MediatR, we are not sure about it. The most upvoted non-library comment was: "Batteries included, stay away from dependencies." That context matters when you read this list. LINQPad isn't a NuGet package, but it kept coming up. Teams build entire support workflows in it. Vogen surprised me. Type-safe value objects generated at compile time, without runtime costs. I've seen orderId/customerId bugs in production. This solves such kinds of problems.

I built a free .NET 10 Clean Architecture template. 100 hours of decisions, compressed into one starter you can clone and ship from. 𝗘𝘃𝗲𝗿𝘆 𝗳𝗲𝗮𝘁𝘂𝗿𝗲. 𝗘𝘃𝗲𝗿𝘆 𝗱𝗲𝗰𝗶𝘀𝗶𝗼𝗻 👇 𝗔𝗿𝗰𝗵𝗶𝘁𝗲𝗰𝘁𝘂𝗿𝗲 → 4-layer Clean Architecture (Api, Infrastructure, Application, Domain) → Strict dependency rules enforced by 9 architecture tests → Domain layer has zero external dependencies 𝗖𝗤𝗥𝗦 → Manual ICommand/IQuery interfaces (no MediatR, no licensing risk) → 40 lines of infrastructure code total → Feature folder organization 𝗔𝘂𝘁𝗵𝗲𝗻𝘁𝗶𝗰𝗮𝘁𝗶𝗼𝗻 → Identity with JWT bearer tokens → Refresh token rotation → Role-based authorization → Seeded admin user (login and go) 𝗖𝗮𝗰𝗵𝗶𝗻𝗴 → Microsoft HybridCache (L1 in-memory L2 Redis) → Built-in stampede protection → Automatic serialization 𝗔𝗣𝗜 𝗗𝗼𝗰𝘀 → Scalar (not Swagger) with modern UI → JWT auth pre-configured for testing endpoints 𝗢𝗯𝘀𝗲𝗿𝘃𝗮𝗯𝗶𝗹𝗶𝘁𝘆 → .NET Aspire orchestration (one `dotnet run` starts everything) → OpenTelemetry traces, metrics, and logs → Aspire Dashboard for local debugging 𝗘𝗿𝗿𝗼𝗿 𝗛𝗮𝗻𝗱𝗹𝗶𝗻𝗴 → Result pattern with typed errors (NotFound, Validation, Conflict) → Automatic mapping to correct HTTP status codes → FluentValidation via endpoint filters 𝗗𝗮𝘁𝗮 𝗔𝗰𝗰𝗲𝘀𝘀 → EF Core 10 with PostgreSQL → No Repository pattern (DbContext is the repository) → Migrations seed data applied on first startup 𝗧𝗲𝘀𝘁𝗶𝗻𝗴 → 9 architecture tests (layer dependency enforcement) → 8 unit tests (handler logic) → xUnit v3 FluentAssertions 𝗠𝗼𝗱𝗲𝗿𝗻 .𝗡𝗘𝗧 → .slnx solution format (merge-friendly) → Central Package Management → Primary constructors collection expressions → C# 14 𝗦𝘁𝗮𝘁𝘀: 17 tests passing. 0 warnings. 0 commercial dependencies. This is FullStackHero's Little Brother! Every choice has a "why" behind it. I didn't just pick popular libraries. I picked what I'd actually use in production. Grab it from codewithmukesh.com/resources…

I've been building with .NET for years. Here's the exact learning path I'd follow if I were starting over in 2026 👇 Most developers fail not because they lack talent, but because they don't have a clear path. They jump between random tutorials, leaving gaps that hurt in interviews and on the job. If you want to become a .NET developer in 2026, you need to know these topics: 𝗙𝗼𝘂𝗻𝗱𝗮𝘁𝗶𝗼𝗻 • HTTP/HTTPS, DNS, APIs • OOP (Classes, Inheritance, Interfaces) • Git & GitHub • AI Tools (Claude Code, GitHub Copilot, Cursor) 𝗖# & .𝗡𝗘𝗧 𝟭𝟬 • Primary constructors, Records • Collection expressions, Pattern matching • Nullable reference types, Raw string literals • .NET CLI (dotnet new, build, run, publish) • NuGet package management 𝗔𝗦𝗣.𝗡𝗘𝗧 𝗖𝗼𝗿𝗲 𝗕𝗮𝘀𝗶𝗰𝘀 • Controllers vs Minimal APIs • Dependency Injection & Service Lifetimes • Middlewares & Request Pipeline • Options Pattern & Configuration 𝗗𝗮𝘁𝗮𝗯𝗮𝘀𝗲𝘀 • PostgreSQL / SQL Server • EF Core (DbContext, Migrations, Fluent API) • Dapper for performance-critical queries • Redis for caching 𝗦𝗲𝗰𝘂𝗿𝗶𝘁𝘆 • JWT Authentication • Refresh Tokens • OAuth Providers (Keycloak, Cognito, Auth0) • Role & Policy-based Authorization 𝗧𝗲𝘀𝘁𝗶𝗻𝗴 • xUnit FluentAssertions Moq • Integration Testing (WebApplicationFactory) • TestContainers for real database tests 𝗔𝗿𝗰𝗵𝗶𝘁𝗲𝗰𝘁𝘂𝗿𝗲 (𝗦𝗲𝗻𝗶𝗼𝗿) • Clean Architecture / Onion Architecture • CQRS MediatR • Domain-Driven Design basics • Modular Monolith → Microservices 𝗖𝗹𝗼𝘂𝗱 & 𝗗𝗲𝘃𝗢𝗽𝘀 • Docker & Docker Compose • CI/CD (GitHub Actions) • AWS / Azure basics • Terraform for IaC This is what you need to become a complete .NET developer in 2026. Bookmark this post. You will come back to it. 📌 Full roadmap with learning resources: codewithmukesh.com/blog/dotn… 👉 Join 8,200 .NET developers reading my weekly newsletter: newsletter.codewithmukesh.co…

First code preview of AgentEval: result.ToolUsage!.Should()     .HaveCalledTool("SearchFlights")         .BeforeTool("BookFlight")     .And()     .NeverCallTool("DeleteAllCustomers")     .HaveNoErrors(); FluentAssertions for AI agents. Native .NET. This is just the beginning. 🧵 #AgentEval #dotnet #CSharp

Although version 8.9 of #fluentassertions is on the way, we couldn't help ourselves and also ship a tiny bugfix for version 7. See github.com/fluentassertions/…

It's been a year, did anybody actually pay for FluentAssertions?

👉 I just created something I wish I had 5 years ago. It will save you 120 hours of setup and development. I have created the best Modular Monolith project template for .NET developers you can ever find. This isn't your typical starter kit — it's a production-ready template that organizes your code into loosely coupled modules deployed as a single, maintainable application. This is the biggest thing I have ever given for free. Inside, you'll find: 📌 Production-grade architecture: ↳ Vertical Slice & Clean Architecture patterns ↳ Built-in authentication with JWT & refresh tokens ↳ OpenTelemetry, Validation, Logging, Error Handling and Tests out of the box. 📌 Modern tech stack: ↳ EF Core, FluentValidation, ASP .NET Core Minimal APIs ↳ Docker with PostgreSQL, Seq, and Jaeger 📌 High-quality code standards: ↳ Preconfigured .editorconfig and static code analysis ↳ Comprehensive unit, integration, and architecture tests 📌 Fully functional modules: ↳ Users Module: Secure authentication flows ↳ Shipments Module: Full lifecycle shipment management ↳ Carriers Module: Seamless carrier integration ↳ Stocks Module: Accurate inventory tracking And the most important part: No AutoMapper, MediatR, FluentAssertions and other unnecessary 3rd party packages. The code quality of this project meets the highest standards, equivalent to those I maintain in enterprise-level production applications. Why trust me? Each Tuesday, 𝟮𝟬,𝟬𝟬𝟬 developers receive my newsletter filled with practical tips on building robust, scalable .NET applications with high quality source code. I've poured all my experience into this template to help you deliver faster, better code. Skip all the boilerplate — start with a fully configured Modular Monolith template so you can focus on delivering business value from day one. Want this template? Here's how you get it: 1️⃣ Follow me on LinkedIn 2️⃣ Comment "Template" below 👇 3️⃣ I'll send the Template your way! Ready to transform your .NET development? — ♻️ Repost to help others get the template ➕ Follow me ( Anton Martyniuk ) and comment "Template" now, and you will get the best Modular Monolith Template you can't find anywhere else.