Roslyn analyzer support in Rider 2018.1 EAP

Roslyn analyzers in JetBrains RiderWhile writing code, Rider performs code analysis and helps us spot any errors, problems or potential improvements. With over 2.400 code inspections that come from ReSharper and WebStorm, Rider helps us improve code quality in every language it supports (C#, VB.NET, F#, HTML, JavaScript TypeScript, CSS, …).

The latest Rider 2018.1 EAP build goes one step further and adds Roslyn analyzer support as a new (experimental) feature! Let’s see!

Why Roslyn support in Rider?

Many open source projects as well as development teams are writing their own analyzers to provide additional tooling for the frameworks they build. For example the xUnit.net folks have a set of Roslyn-based analyzers that help with things like making sure Fact methods do not have parameters – often combined with a code fix as well.

Using xUnit analyzers in JetBrains Rider

By adding Roslyn support to Rider, developers now get the best of all worlds! Not only will you get the 2.400+ inspections and quick fixes from ReSharper and WebStorm, you can now get community fixes from Roslyn analyzers!

Enabling Roslyn analyzers in Rider

Roslyn analyzer support is disabled by default. We can enable it in the settings under Editor | Inspection Settings | Roslyn Analyzers.

Enable Roslyn analyzers in Rider

Once enabled and settings are saved, Rider will scan for installed Roslyn analyzers.

Installing and using Roslyn analyzers

Many Roslyn analyzers ship as NuGet packages, which means we can use Rider’s NuGet client to search for analyzers. Right now, installing analyzers via NuGet only works on .NET Core. Referencing analyzers in our .csproj using <Analyzer Include="path\to\analyzers.dll"> is supported for all frameworks and project types.

In a .NET Core web application, let’s install the DisableDateTimeNow analyzer, a simple analyzer which checks for usage of DateTime.Now and will suggest using DateTime.UtcNow instead.

Install Roslyn analyzer in Rider using NuGet client

After installation, Rider runs the analyzer on our code. It displays a hint, suggestion, warning or error in the editor. The “light bulb” in the left gutter is displayed when our cursor is on the code issue, and shows a Roslyn logo to differentiate between Rider’s own code analysis and code analysis provided by a custom analyzer. Using Alt+Enter, we can invoke the corresponding fix.

Analyzers may also run as part of the build in Rider. If an analyzer has a default severity of warning or error, it will show in the build output as such.

Roslyn analyzer marked error breaks build

Configuring analyzer severity

Hints and suggestions will show as light “squiggles” in our code, while for warnings and errors we will see clear yellow and red colors. For every analysis, we can configure its severity from the Alt+Enter popup.

Configure severity using Alt+Enter

Severity can also be configured in Rider’s settings, under Editor | Inspection Settings | Roslyn Analyzers. The full list of referenced Roslyn analyzers is displayed here, making it easier to change severity multiple analyzers at once.

Configuring analyzer severity in the IDE settings.

Solution-Wide Analysis

Like with any other code issue, Rider lets us find similar issues in the current file, project or solution and will run Roslyn analyzers for that scope.

Run analyzer on project or solution

We can also include Roslyn analyzers in Solution-Wide Analysis (enable/disable it from the settings). When opening the Errors in Solution tool window, we can inspect code analysis results powered by Rider as well as those coming from Roslyn. Note I enabled “Show Warnings” here as well.

Solution wide analysis includes results from Roslyn analyzers

Current limitations

Roslyn analyzer support in Rider is still experimental and there are a number of things we’re still working on.

If you encounter any issues while using Roslyn analyzers in Rider, please open an issue in our tracker.

Give the latest Rider 2018.1 EAP build a try! We’d love to hear your feedback!

About Maarten Balliauw

Maarten Balliauw is a Developer Advocate at JetBrains, working on .NET tools. He focuses on .NET, Azure, web technologies and application performance. Maarten is a frequent speaker at various national and international events. In his free time, he brews his own beer. Follow him on Twitter or check his personal blog.
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31 Responses to Roslyn analyzer support in Rider 2018.1 EAP

  1. Great to see Roslyn Analysers are now supported in Rider. It’s one of the things I’ve missed since switching from Visual Studio, that and Peek Definition *hint, hint, wink, wink*

  2. Blazor says:

    Hi, did you start on Rider support for Blazor? Thanks!

    https://github.com/aspnet/Blazor

  3. Do you also support Rolsyn based code refactorings? Or just analyzers? Are you planning to support them?

  4. Rob says:

    Oh wow!!! I am seriously impressed! I was thinking about this just the other day, as we use StyleCop Analyzers (which requires Roslyn Analyzers). This is why I pay you guys: nice job!

  5. Joshua Light says:

    Hi!

    New feature is awesome!

    One question: how can I inject included analyzer into build process so that every detected error will result in failed build?

  6. Johannes Ebner says:

    This is great! However, StyleCop.Analyzers and the quick fixes are not showing up for me or my team members. But they do in Visual Studio.

  7. Rider 2018.2.1
    Roslyn is enabled by default, can this be changed in the registry or an install parameter please?

  8. Deni35 says:

    How can I disable default analizer? I want only StyleCop to work.
    But I see many warnings like next (this is not StyleCop).
    Using directive is not required by the code and can be safely removed
    Property ‘***’ is never used

  9. Vladimir Panchenko says:

    Does Rider support Roslyn code fixes and refactorings as well? Many projects such as mentioned xUnit analyzers include them.
    Also, does it support other Roslyn features such as custom IntelliSense providers?

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