areisler / visual-studio-intellisense-errors

Contains a repro of a Visual Studio IntelliSense problem showing build warnings as errors

visual-studio-intellisense-errors

Contains a repro for a problem where Roslyn analyzer warnings are wrongly shown as errors in Visual Studio IntelliSense design-time-build.

Problem summary

This repo contains a code sample showing a problem in Visual Studio IntelliSense behavior. The sample contains a class library, which builds just fine when running through the compiler, but Visual Studio displays IntelliSense errors in the Error Windows and in the code with underlined squiggles.

Detailed repro steps

Execute the steps

Start Visual Studio 2019/2022 and execute the following steps:

1. Clone this repo
2. Open the src\RoslynIntellisenseErrorsRepro.sln solution
3. Build the solution
4. Close and reopen the solution
5. Open the \src\VisualStudioIntellisenseErrors\FxCopRules\CA1062\Violation.cs file
6. Open the Visual Studio ErrorList
7. Change the issue filter to show Build + IntelliSense

Important: It is required to reopen Visual Studio after the repo was cloned and the solution build for the first time (including first package restore)

Observe the problem

Once the IntelliSense has completed its initialization the ErrorList will show one detected issue for the rule CA1062 as Error

despite the ruleset configuration sets its severity to Warning and the project property TreatWarningsAsErrors configured as <TreatWarningsAsErrors>false</TreatWarningsAsErrors>:

Steps to create the sample app from scratch

General preparation steps:

1. Install .NET Framework 4.8 SDK
2. Use a latest version of the Visual Studio 2019/2022 (for version details see separate section below)
3. Create a new project using the Windows Class Library (.NET Framework) template
4. Add Analyzer package Microsoft.CodeAnalysis.NetAnalyzers, 6.0.0 (nuget.org)
5. Create a new ruleset file configured with e.g. rule CA1062 set to Warning (see default.ruleset). The configuration of all the other rules from the same NuGet Analyzer package does not matter for the purpose of this repro.
6. Add code which violates against the CA1062 rule (see Violation.cs).

Special preparation steps required to reveal the problem:

1. Create build\default.props containing the following properties:

  <PropertyGroup>
    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
  </PropertyGroup>

2. Add the following properties to the project file:

  <Import Project="..\..\build\default.props" />
  <PropertyGroup>
    <CodeAnalysisRuleSet>..\default.ruleset</CodeAnalysisRuleSet>
    <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
  </PropertyGroup>

Tested with Visual Studio versions

Microsoft Visual Studio Enterprise 2019
Version 16.11.7
VisualStudio.16.Release/16.11.7+31911.196
Microsoft .NET Framework
Version 4.8.03752

Installed Version: Enterprise

Microsoft Visual Studio Enterprise 2022
Version 17.0.2
VisualStudio.17.Release/17.0.2+31919.166
Microsoft .NET Framework
Version 4.8.03752

Installed Version: Enterprise

visual-studio-intellisense-errors's Issues

Retest the scenario using Microsoft.CodeAnalysis.NetAnalysers package