Do not export IServiceProvider

[AArnott]

VS extensions should not export System.IServiceProvider (without an explicit, non-default contract name). This is because this is a globally shared type name and if two folks exported it, it would cause everyone who imports it to fail since they expect only one export but got more than one. Generally speaking, you should only export your own types, or BCL types with an explicit contract name that has your namespace in it.

For example, this is wrong:

[Export(typeof(IServiceProvider))]

But this is OK:

[Export("Github.ExtensionForVS.IServiceProvider", typeof(IServiceProvider))]

This is where GitHub's extension violates this rule.

Now in this particular case, if the IServiceProvider that you actually want is the VS global service provider, you don't need to export anything, but simply import SVsServiceProvider (which derives from IServiceProvider):

[Import]
SVsServiceProvider GlobalServiceProvider { get; set; }

[haacked]

It doesn't look like we ever import IServiceProvider anyways. We already import SVsServiceProvider in a couple of places. I have a fix coming.

[haacked]

Ok, not so trivial. If I just remove that Export, the extension does not load. I'll need to defer to @shana to remind me of why we're exporting that interface directly.

[shana]

@haacked Yeah, it'll require a few tweaks to things. We export that interface directly because the Desktop code does and we grabbed a lot of code directly off of it. But the desktop app controls its environment and we don't, so our constraints are different. I'll whip up a PR with the needed changes.

[AArnott]

Thank you, @haacked

[haacked]

@AArnott no problem, but it was @shana who did the actual work and deserves all the credit. ✨

[AArnott]

Ah yes, Thanks @shana

[shana]

😄