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Jan Jones

@janjones.me.bsky.social

C# (Roslyn) compiler dev at Microsoft https://github.com/jjonescz

49 Followers  |  15 Following  |  12 Posts  |  Joined: 21.11.2023  |  1.6396

Latest posts by janjones.me on Bluesky

Yes, it should work. .NET 10 rc1 is even the version of compilers included by default. I just tried what you described but it works fine for me. Can you try in a fresh private window, perhaps there are some old files interfering?

05.10.2025 16:54 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0
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Fully revamped the tree view 🌳 in .NET Lab. Now with cursor syncing. Can display syntax, IOperation, and symbol info. #dotnet #csharp #roslyn #dotnetlab

05.10.2025 15:58 β€” πŸ‘ 16    πŸ” 3    πŸ’¬ 1    πŸ“Œ 0
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Reuse CSC arguments in file-based app runs by jjonescz Β· Pull Request #50635 Β· dotnet/sdk Part of #48011. This optimization saves CSC arguments when MSBuild runs and then reuses them in subsequent runs so dotnet run file.cs can skip MSBuild and invoke only the compiler. In my simple exp...

Big improvements to the performance of developing C# file-based incoming. Subsequent builds/runs will cache MSBuild outputs & directly invoke the C# compiler if inputs don't change. This in addition to the work in rc.1 to avoid MSBuild completely for simple file-based apps
github.com/dotnet/sdk/p...

11.09.2025 17:58 β€” πŸ‘ 18    πŸ” 6    πŸ’¬ 0    πŸ“Œ 0
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Added a small but useful feature to copy the current URL in .NET Lab (lab.razor.fyi). It has a keyboard shortcut too: Ctrl+; πŸ“‹
#dotnet #csharp #roslyn #dotnetlab

06.09.2025 13:04 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
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.NET Lab (lab.razor.fyi) just gained new configuration options inspired by `dotnet run app.cs`. Reference any NuGet packages via `#:package` or quickly change config via `#:property` (with editor suggestions to guide you). πŸš€βš™οΈ

26.07.2025 15:53 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Check out all the improvements to file-based apps (dotnet run app.cs) in preview.6 that went out today!

github.com/dotnet/core/...

15.07.2025 17:53 β€” πŸ‘ 13    πŸ” 5    πŸ’¬ 2    πŸ“Œ 0
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Behind the scenes of dotnet run app.cs: Exploring the .NET 10 preview - Part 2 In this post I looks at how the new single-file .NET run experience is implemented inside the .NET SDK, focusing on how the virtual-project file is built

Blogged: Behind the scenes of dotnet run app.cs - Exploring the .NET 10 preview - Part 2

andrewlock.net/exploring-do...

In this post I looks at how the new single-file .NET run experience is implemented inside the .NET SDK, focusing on how the virtual-project file is built.

#dotnet #csharp

08.07.2025 17:47 β€” πŸ‘ 6    πŸ” 3    πŸ’¬ 0    πŸ“Œ 0
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.NET Lab (lab.razor.fyi) now has Code Actions πŸš€ Very useful when you paste some code snippet and want to add missing usings. But it can do much more - all Roslyn code fixes are included.

28.06.2025 10:22 β€” πŸ‘ 12    πŸ” 6    πŸ’¬ 0    πŸ“Œ 0
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Added semantic highlighting to .NET Lab (lab.razor.fyi)

22.06.2025 13:04 β€” πŸ‘ 4    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

Yes, should be in .NET 10 Preview 6

15.06.2025 11:50 β€” πŸ‘ 4    πŸ” 1    πŸ’¬ 1    πŸ“Œ 0
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Add support for `dotnet file.cs` (without explicit `run` subcommand) by jjonescz Β· Pull Request #48387 Β· dotnet/sdk Resolves #49202.

And soon just
dotnet app.cs
😎

github.com/dotnet/sdk/p...

14.06.2025 05:32 β€” πŸ‘ 25    πŸ” 8    πŸ’¬ 4    πŸ“Œ 0
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Completions and live diagnostics are now much improved and enabled by default in .NET Lab (lab.razor.fyi). Stay tuned for more enhancements to the editing experience coming soon.

16.05.2025 07:05 β€” πŸ‘ 2    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0
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Shared lab.razor.fyi snippets are now cached, so you can see the output even before the compiler is initialized. (Nevertheless, more optimizations of loading times are coming.) Example: lab.razor.fyi#47Lm4gooyk8v...

02.03.2025 09:47 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
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Added this cool loading animation to lab.razor.fyi. Suddenly the loading feels faster ⚑

21.02.2025 17:34 β€” πŸ‘ 6    πŸ” 3    πŸ’¬ 0    πŸ“Œ 0
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Old version using Bootstrap

20.12.2024 17:33 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
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Updated lab.razor.fyi to use Microsoft Fluent UI. Quite happy with the result. Also got dark mode for free.

20.12.2024 17:33 β€” πŸ‘ 5    πŸ” 1    πŸ’¬ 1    πŸ“Œ 0

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