SonarScanner for .NET

The SonarScanner for .NET is the recommended way to launch an analysis for projects using the msbuild or dotnet build tools. It is the result of a collaboration between SonarSource and Microsoft.

SonarScanner for .NET is distributed as a standalone command-line executable, as an extension for Azure DevOps, and as a plugin for Jenkins.

 It supports .NET Core on every platform (Windows, macOS, Linux).

Prerequisites

• Java 17 or later
• The SDK corresponding to your build system:
  • .NET Framework v4.6.2 - either Build Tools for Visual Studio 2015 Update 3 or the Build Tools for Visual Studio
  • .NET Core SDK 3.1 and above (for .NET Core version of the scanner or if you plan to use .NET Core Global Tool)

Installation

Standalone executable

• Expand the downloaded file into the directory of your choice. We'll refer to it as $install_directory in the following steps.
  • On Windows, you might need to unblock the ZIP file first (right-click File > Properties > Unblock).
  • On Linux/OSX you may need to set execute permissions on the files in $install_directory/sonar-scanner-(version)/bin.
• Uncomment, and update the global settings to point to SonarCloud by editing $install_directory/SonarQube.Analysis.xml. Values set in this file will be applied to all analyses of all projects unless overwritten locally.
  Consider setting file system permissions to restrict access to this file:

<SonarQubeAnalysisProperties  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://www.sonarsource.com/msbuild/integration/2015/1">
  <Property Name="sonar.host.url">https://sonarcloud.io</Property>
  <Property Name="sonar.token">[my-user-token]</Property>
</SonarQubeAnalysisProperties>

• Add $install_directory to your PATH environment variable.

.NET Core Global Tool

dotnet tool install --global dotnet-sonarscanner --version x.x.x

The --version argument is optional. If it is omitted, the latest version will be installed. A complete list of releases is available on the NuGet page

.NET Core Global Tool is available from .NET Core 3.1+.

Use

There are two versions of the SonarScanner for .NET. In the following commands, you need to pass an authentication token using the sonar.token property.

"Classic" .NET Framework invocation

The first version is based on the "classic" .NET Framework. To use it, execute the following commands from the root folder of your project:

SonarScanner.MSBuild.exe begin /k:"project-key" /o:"<organization>" /d:sonar.token="<token>"
MSBuild.exe <path to solution.sln> /t:Rebuild
SonarScanner.MSBuild.exe end /d:sonar.token="<token>"

Note: On macOS or Linux, you can also use mono <path to SonarScanner.MSBuild.exe>.

.NET Core and .NET Core Global Tool invocation

The second version is based on .NET Core which has a very similar usage:

dotnet <path to SonarScanner.MSBuild.dll> begin /k:"project-key" /o:"<organization>" /d:sonar.token="<token>"
dotnet build <path to solution.sln> --no-incremental
dotnet <path to SonarScanner.MSBuild.dll> end /d:sonar.token="<token>" 

The .NET Core version can also be used as a .NET Core Global Tool. After installing the Scanner as a global tool as described above, it can be invoked as follows:

dotnet tool install --global dotnet-sonarscanner
dotnet sonarscanner begin /k:"project-key" /o:"<organization>" /d:sonar.token="<token>"
dotnet build <path to solution.sln> --no-incremental
dotnet sonarscanner end /d:sonar.token="<token>"

In summary, the invocation of the SonarScanner for .NET will depend on the scanner flavor:

Notes:

• The .NET Core version of the scanner does not support TFS XAML builds and automatic finding/conversion of Code Coverage files. Apart from that, all versions of the Scanner have the same capabilities and command-line arguments.

Analysis steps

Begin

The begin step is executed when you add the begin command-line argument. It hooks into the build pipeline, downloads SonarCloud quality profiles and settings, and prepares your project for analysis.

Begin step command line parameters:

• /k:<project-key>  
  • [required] Specifies the key of the analyzed project in SonarCloud.
• /n:<project name>
  • [optional] Specifies the name of the analyzed project in SonarCloud. 
  • Adding this argument will overwrite the project name in SonarCloud if it already exists.
• /v:<version>
  • [recommended] Specifies the version of your project.
• /o:<organization>
  • [required] Specifies the name of the target organization in SonarCloud.
• /d:sonar.token=<token> or <username>
  • [recommended] Specifies the authentication token or username used to authenticate with to SonarCloud. 
  • If this argument is added to the begin step, it must also be added to the end step.
• /d:sonar.verbose=true
  • [optional] Sets the logging verbosity to detailed. 
  • Add this argument before sending logs for troubleshooting.
• /d:sonar.dotnet.excludeTestProjects=true
  • [optional] Excludes Test Projects from analysis. 
  • Add this argument to improve build performance when issues should not be detected in Test Projects.
• /d:<analysis-parameter>=<value>
  • [optional] Specifies an additional SonarCloud analysis parameter.
  • You can add this argument multiple times.

For detailed information about all available parameters, see Analysis Parameters.

Build

Between the begin and end steps, you need to build your project, execute tests and generate code coverage data. This part is specific to your needs, and it is not detailed here. See .NET Test coverage for more information.

The rules configured in your SonarCloud Quality Profile are run during the build, and it is expected that analyzing with SonarCloud can increase build duration from 4 to 8 times. The impact on duration will vary by project and by what rules are enabled; some rules are simple to execute and others take additional time to have the impact and precision expected of them

End

The end step is executed when you add the "end" command-line argument. It cleans the MSBuild/dotnet build hooks, collects the analysis data generated by the build, the test results, and the code coverage, and then uploads everything to SonarCloud. There are only two additional arguments that are allowed for the end step.

End step command line parameters:

• /d:sonar.token=<token> or /d:sonar.token=<username>
  • This argument is required if it was added to the begin step.

Known limitations

• MSBuild versions older than 15 are not supported.
• Web Application projects are supported. Legacy Web Site projects are not.
• Projects targeting multiple frameworks and using preprocessor directives could have slightly inaccurate metrics (lines of code, complexity, etc.) because the metrics are calculated only from the first of the built targets.

Code Coverage

In an Azure DevOps / TFS environment, test files are automatically retrieved as follows:

• A search is done for .trx files in any TestResults folder located under $Build.SourcesDirectory.
• If no .trx files are found there, then a fallback search is performed under $Agent.TempDirectory.

Once the .trx files have been found, their .coverage counterparts are retrieved and converted to .coveragexml files for upload to SonarCloud.

As stated above, this will work only with the .NET Framework version of the scanner.

See Test Coverage for more information.

Excluding projects from analysis

Some project types, such as Microsoft Fakes, are automatically excluded from the analysis. To manually exclude a different type of project from the analysis, place the following in its .xxproj file.

<!-- in .csproj -->
<PropertyGroup>
  <!-- Exclude the project from analysis -->
  <SonarQubeExclude>true</SonarQubeExclude>
</PropertyGroup>

Advanced topics

Analyzing MSBuild 12, 14, and 15 projects with MSBuild 16

The Sonar Scanner for .NET requires your project to be built with MSBuild 16. We recommend installing Visual Studio 2017 or later on the analysis machine in order to benefit from the integration and features provided with the Visual Studio ecosystem (VSTest, MSTest unit tests, etc.).

Projects targeting older versions of the .NET Framework can be built using MSBuild 16 by setting the "TargetFrameworkVersion" MSBuild property as documented by Microsoft:

• How to: Target a Version of the .NET Framework
• MSBuild Target Framework and Target Platform

For example, if you want to build a .NET 3.5 project, but you are using a newer MSBuild version:

MSBuild.exe /t:Rebuild /p:TargetFramework=net35

If you do not want to switch your production build to MSBuild 16, you can set up a separate build dedicated to the SonarCloud analysis.

Detection of test projects

You can read a full description of that subject on our wiki here.

Per-project analysis parameters

Some analysis parameters can be set for a single MSBuild project by adding them to its .csproj file.

<!-- in .csproj -->
<ItemGroup>
  <SonarQubeSetting Include="sonar.stylecop.projectFilePath">
    <Value>$(MSBuildProjectFullPath)</Value>
  </SonarQubeSetting>
</ItemGroup>

Analyzing languages other than C# and VB

For newer SDK-style projects (used by .NET Core, .NET 5, and later), the SonarScanner for .NET will analyze all file types supported by the available language plugins unless explicitly excluded.

If you have an esproj project type, make sure to use Microsoft.VisualStudio.JavaScript.SDK version 0.5.74-alpha or later to ensure the SonarScanner for .NET recognizes the esproj contents for scanning.

For older-style projects, the scanner will only analyze files listed in the .csproj or .vbproj project file. Usually, this means that only C# and VB files will be analyzed. To enable the analysis of other types of files, include them in the project file.

More specifically, any files included by an element of one of the ItemTypes in this list will be analyzed automatically. For example, the following line in your .csproj or .vbproj file:

<Content Include="foo\bar\*.js" />

will enable the analysis of all JS files in the directory foo\bar because Content is one of the ItemTypes whose includes are automatically analyzed.

You can also add ItemTypes to the default list by following these directions.

You can check which files the scanner will analyze by looking in the file .sonarqube\out\sonar-project.properties after MSBuild has finished.

Using SonarScanner for .NET with a Proxy

On build machines that connect to the Internet through a proxy server you might experience difficulties connecting to SonarQube. To instruct the Java VM to use specific proxy settings use the following value:

SONAR_SCANNER_OPTS = "-Dhttp.proxyHost=yourProxyHost -Dhttp.proxyPort=yourProxyPort"

Where yourProxyHost and yourProxyPort are the hostname and the port of your proxy server. There are additional proxy settings for HTTPS, authentication, and exclusions that could be passed to the Java VM. For more information, see the following article: https://docs.oracle.com/javase/8/docs/technotes/guides/net/proxies.html.

You also need to set the appropriate proxy environment variables used by .NET. HTTP_PROXY, HTTPS_PROXY, ALL_PROXY, and NO_PROXY are all supported. You can find more details here.

Known issues

I have multiple builds in the same pipeline, each of them getting analyzed even if the Run Code Analysis has already been executed.

We don't uninstall the global ImportBefore targets to support concurrent analyses on the same machine. The main effect is that if you build a solution where a .sonarqube folder is located nearby, then the sonar-dotnet analyzer will be executed along with your build task.

To avoid that, you can disable the targets file by adding a build parameter:

msbuild /p:SonarQubeTargetsImported=true
dotnet build -p:SonarQubeTargetsImported=true