Analyzers not being recognized in Dev17 Preview 6

[akhera99]

Version Used:
Version 17.0.0 Preview 6.0 [31815.197.d17.0]
Steps to Reproduce:
Insert:

public class Class
{
    public void Method()
    {
        int x = 5;
        x = 2;
     }
}

Expected Behavior:

public class Class
{
    public void Method()
    {
        int x = 5;
        x = 2; <----- analyzer on this line indicating redundant assignment
     }
}

Actual Behavior:
No diagnostic is shown.

[mavasani]

Fixed with #57294

[mavasani]

Actually, I am going to re-activate this issue to track why we did not report any warning diagnostics for analyzer load failure in IDE, we should have ideally called this method to report diagnostics:

roslyn/src/Features/Core/Portable/Diagnostics/AnalyzerHelper.cs

Line 178 in a8a030c

public static DiagnosticData CreateAnalyzerLoadFailureDiagnostic(AnalyzerLoadFailureEventArgs e, string fullPath, ProjectId? projectId, string? language)

[mavasani]

Investigated a bit about failure to report analyzer load diagnostics. This is not a regression, we have never had support to report analyzer load failure diagnostics in OOP. Analyzers are loaded/instantiated in both devenv.exe and OOP process, and we do have code to report load failure diagnostics if analyzer fails to load in devenv.exe. For all third party analyzers, any analyzer that fails to load, say due to missing dependency accessed in its ctor, it will fail in both devenv.exe and OOP and we will report those failures as diagnostics in devenv.exe. IDE CodeStyle analyzers are special in the sense that they are defined in Roslyn assemblies (Features with dependencies to Workspaces and Compiler), so the analyzer load is slightly different in both processes. Also, if any analyzer throws an exception during analyzer callbacks while executing in OOP, we do report these as AD0001 diagnostics in error list, we also have tests for it.

In short, I don't think we need to any more work here. This is just a very special case where we don't report load failure diagnostics, and it doesn't affect any other analyzer packages.

[dibarbet]

@mavasani I'm hitting this bug (or at least one with the same symptoms in preview 7 still, even with your change.
Using this build

Which is using this commit - https://github.com/dotnet/roslyn/commits/68d3c0e77ff8607adca62a883197a5637a596438

This does not repro in p5.

To repro, download \\mlangfs1\public\v-irjain\RealWorldSoln\MaterialSkin-master.zip , open the sln, open ColorScheme.cs and change Color on line 7 to Colors and note the lack of diagnostics

Was found via https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1393716

[mavasani]

I have tried to repro this in a bunch of ways, but unable to repro it:

1. Open solution from VS using the desktop CLR host for OOP
2. Open solution from VS using the core CLR host for OOP
3. Open solution from VS started from RoslynDevHive using the core CLR host for OOP (based off Roslyn sources in release/dev17.0 branch)

I always get the red squiggle and lightbulb for Colors. I'll now try the liveshare repro to see if I see any different results.

NOTE: I installed Dev17.0 Preview7 from https://docs.microsoft.com/en-us/visualstudio/releases/2022/release-notes-preview#17.0.0-pre.7.0 and tried, but still unable to repro.

[mavasani]

@jinujoseph @dibarbet @vatsalyaagrawal I have tried to repro this issue on Dev17.0 Preview7 build installed from https://docs.microsoft.com/en-us/visualstudio/releases/2022/release-notes-preview#17.0.0-pre.7.0 and can confirm that I can only repro it under liveshare session. Squiggles work fine in regular mode, seem to just be missing in liveshare mode. See the below gif confirming the same:

[dibarbet]

@mavasani I just figured out the repro - it only happens when you re-open the solution with the file already open. When I open VS without the file already open, it does not reproduce. See the gif below.

[mavasani]

Closing this issue based on the offline discussion with @dibarbet