Improve clarity/reliability of file-based program restore experience

[RikkiGibson]

Currently the IDE is quite slow/unresponsive/unreliable when it comes to restoring new packages when edits to #:package or similar directives are made. We need to investigate and improve this.

[CyrusNajmabadi]

Shouldn't that be owned by the package management people? I would not expect that we need to investigate that ourselves.

[RikkiGibson]

I think at least part of the problem is on us, as current investigation indicates that the LanguageServerProjectLoader is not making the call to do the restore at the appropriate time.

[CyrusNajmabadi]

I'm surprised we are restoring at all. That feels like something an external watch system so should take care of when this changes on disk (so only when persisted).
I would not expect this to happen live while a user types the new info in the file and hasn't saved it.

Roslyn doesn't own restore for normal projects right?

[RikkiGibson]

Roslyn doesn't own restore for normal projects right?

It does. @dibarbet might be able to provide more context on that.

I would not expect this to happen live while a user types the new info in the file and hasn't saved it.

That's right. The language server's mechanism for doing restores is based on file watchers, so, a restore definitely won't be performed based on live/unsaved edits.

[CyrusNajmabadi]

if it is based on changes to files on disk, i would far prefer this have nothing to do with roslyn, and everything to do with dotnet and them watching for this stuff :)

[CyrusNajmabadi]

It does.

Oh wow.. :'(

[dibarbet]

We own the entire project system for C# standalone scenarios, so we also own watching for changes and running restore. IIRC we already setup file watchers for nuget packages so I would have thought this would work.

[CyrusNajmabadi]

We own the entire project system for C# standalone scenarios

I'm not particularly thrilled to hear this. We've been tasked with dropping costs as much as possible. Having us take on project-system responsibilities (instead of having the project system own it) feels like it goes against that goal. :-)