Resharper: Enable warnings on C# 7.0 features?

2
votes

My question is the opposite of just about every question I have found online.

I want to enable C# 7.0 warnings/errors in Resharper (running in VS2017, release just installed today.)

I need to do this because the project I am working on will be published to my workplace's server, and their CI throws fatal errors when C# 7.0 features are used (R# C# 7.0 language feature), so I can't use them (they won't accept any project that fails fatally with their CI.)

They're using Resharper CLI in the CI. So I want to make my Resharper throw the same errors, so I can quickly locate and eliminate C# 7.0 features. My Resharper shows the project as being clean (other than some minor "it might be a problem but it's not for me" things), so I have no fatal errors or even warnings about C# 7.0 when I run a code analysis.

Every question I have seen so far is asking about how to disable warnings about C# 7.0. My Resharper is not throwing any warnings or errors, while the one on our CI is.

I've looked through the options but can't find any obvious "C# 7.0" options. I've looked for something like "maximum supported language/throw an error if language feature in later version is used/etc" but I can't seem to find anything.

Edit: Web.config codedom section:

<system.codedom>
  <compilers>
    <compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.2.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:6 /nowarn:1659;1699;1701" />
  </compilers>
</system.codedom>

It's definitely set to language version 6...

2
resharperc#-7.0

2 Answers

8
votes

You can configure which C# version the build engine uses for each project by right clicking on the project, select Properties, Select the Build section, click on Advanced..., set Language version to whichever version your CI server works with. Once you do this the build will fail when you build locally on any C#7.0 features.

enter image description here

Alternately you could try to get your CI server upgraded to work with C#7.0.

0
votes

The Resharper language rules and Studio rules lie in different places. Studio (and Roslyn) rules you can find in project settings. Resharper keeps warning rules in the [ProjectName].csproj.DotSettings file.

Xml Node:

<s:String x:Key="/Default/CodeInspection/CSharpLanguageProject/LanguageLevel/@EntryValue">CSharp70</s:String>

This file can be safely deleted to get things back to default.

File for warnings 6.0 will be something like that:

<wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
     <s:String x:Key="/Default/CodeInspection/CSharpLanguageProject/LanguageLevel/@EntryValue">CSharp60</s:String>
</wpf:ResourceDictionary>