VSSDK003 flags toolwindows using ToolWindowCreationContext.Unspecified

[microsoft]

VSSDK003 flags toolwindows using ToolWindowCreationContext.Unspecified

[jasonmalinowski]

@AArnott Happy to do so! And in my case, even just a small doc update or something would have been useful. Honestly, what was the trickiest part was actually finding any docs saying what should be done; if there was simple step-by-step that was "override these methods, do this", you could easily have a note there which is "you need a non-default constructor to make the analyzer happy", and I wouldn't have given it much of a second thought.

[AArnott]

Thanks for the great write-up of the problem you found and suggestions for the resolution.
Async tool windows are indeed one of the more complicated things both to test for (which is why I took shortcuts that I thought were heuristically sufficient) and IIRC we don't offer a code fix for it.
I suspect we can take your suggestions though.

[reduckted]

I think I've come across a similar bug, so rather than opening a new issue, I'll add to this one.

The Community.VisualStudio.Toolkit is about to introduce helper classes for creating async tool windows: madskristensen/Community.VisualStudio.Toolkit#25

The only downside to those helper classes is that the VSSDK003 analyzer warning is produced, even though the tool windows are being created asynchronously.

The PR I linked above contains the full sample code, but the two key parts are:

1. You inherit from ToolkitPackage instead of AsyncPackage.
2. The tool window has a parameterless constructor.

Under the hood, the ToolkitPackage class creates the tool windows asynchronously. Any asynchronously resolved services that are needed by the tool window are resolved during the InitializeToolWindowAsync method and the helper class implementation uses those services to create the tool window's Content property value rather than passing those services to the tool window's constructor.