This is an experiment to find a clean way to turn a snippet of text into a WPF component.

See Twitter thread starting here: https://twitter.com/jcansdale/status/1059793737600110592

Unfortunately getting colorization to work isn't simply a case of creating a TextBuffer with a ContentType of CSharp and calling ITextEditorFactoryService.CreateTextView(textBuffer). We need to create a Microsoft.CodeAnalysis.Workspace and associate it with the TextBuffer.

This is the ceremony MiscellaneousFilesWorkspace performs on loose files that aren't associated with a project or Workspace. https://github.com/dotnet/roslyn/blob/2468ad7ccb5fa5982579279454341123b20846ed/src/VisualStudio/Core/Def/Implementation/ProjectSystem/MiscellaneousFilesWorkspace.cs#L338-L341

This project can be tested using TestDriven.Net's Test With > In-Proc (VS SDK) feature. This allows code to be executed inside the current Visual Studio process, MEF services to be prototyped and calls made to Visual Studio services. You can download this extension from the marketplace here.

The ColorizedTextFactoryAdHocTests class is marked with [Export] so it knows to register MEF services in the same assembly and the ShowTextViewHost method is marked with [STAThread] so that it knows to execute on the UI thread.

Any MEF service or Visual Studio service can be passed as a parameter to a "test" method (for Visual Studio services, the service type will be inferred form the interface type).

Here is what happens when I Test With > In-Proc (VS SDK) on the ColorizedTextFactoryAdHocTests.ShowTextViewHost method.

The ColorizedTextFactory.CreateProjectInfoForDocument uses reflection to call CreateProjectInfoForDocument on MiscellaneousFilesWorkspace. This is bad.

I didn't know enough about Roslyn to create a minimal ProjectInfo that is associated with a language, but ideally not a specific file on disk. Any help here would be appreciated.

Thanks everyone who helped on twitter and happy spelunking!