Add the `FSharp` and `Managed` ProjectCapabilties to project evaluation

[baronfel]

Is your feature request related to a problem? Please describe.

Support for item template in the .NET template engine hinges on support for ProjectCapabilties - MSBuild items that signal support for a kind of functionality. We use these to determine which templates are valid for the given project. C# and VB both add ProjectCapabilities for their respective languages, as well as 'all managed languages' in the CurrentVersion targets for each language.

Describe the solution you'd like

I'd like for the F# props and targets to add <ProjectCapability Include="FSharp" /> and <ProjectCapability Include="Managed" /> into a location that is read during evaluation time (not a design-time build) so that advanced features in other product can 'light up' in the same way for F# as they do for C# and VB. C#/VB use Microsoft.LANG.CurrentVersion.targets, but I couldn't find a direct match for that for F#. Might need to consult with the MSBuild team to figure out the most relevant location.

It would be great if this could be scheduled for the 7.03xx/VS 17.6 timeframe.

Describe alternatives you've considered

None

References

• template engine tracking issue: Item templates should pick correct language from project templating#5844

[vzarytovskii]

@baronfel whom should we talk to from MSBuild team regarding this?

[baronfel]

@ladipro and @rainersigwald would be my starting points for this kind of question.

Really any always-included props file for F# would be good enough, but it might be interesting to compare the f# props/targets layout vs C#/VB and see if there are any layering lessons to take away.