Suppressing Code Analysis Rules

Apply a Suppression in “Project Suppression File (GlobalSuppression.cs) – an ideal option.

Project Suppressions

When selecting the Project Supressions File option, the SuppressMessageAttribute is placed in the projects GlobalSuppressions.cs file – Visual Studio will create one automatically. The attribute has overrides which allows you to target the exact place of the rule failure such as a class, method, field, namespace etc.

In my example, I have suppressed botth CA2210 and CA1304 rules in the GlobalSuppressions.cs. Visual Studio generates the code.

// This file is used by Code Analysis to maintain SuppressMessage
// attributes that are applied to this project.
// Project-level suppressions either have no target or are given
// a specific target and scoped to a namespace, type, member, etc.
//
// To add a suppression to this file, right-click the message in the
// Error List, point to "Suppress Message(s)", and click
// "In Project Suppression File".
// You do not need to add suppressions to this file manually.

using System.Diagnostics.CodeAnalysis;

[assembly: SuppressMessage(
"Microsoft.Design",
"CA2210:AssembliesShouldHaveValidStrongNames")]

[assembly:
SuppressMessage(
"Microsoft.Globalization", "CA1304:SpecifyCultureInfo",
MessageId = "System.ServiceModel.FaultReason.#ctor(System.String)",
Scope = "member",
Target = "Wcf.Demo.Service.ErrorHandler.#ProvideFault(System.Exception,System.ServiceModel.Channels.MessageVersion,System.ServiceModel.Channels.Message&)"
)]

Notice the the CA1304 suppression contains Scope and Target properties. This can be changed so that the suppression is scoped to a wider code base such a a namespace.

The benefits of project suppressions is cleaner code, less duplication of the SuppressMessage attribute and easier to remove if failure is fixed. It’s also easier to code review as all failure overrides are in the one place. The only disadvantage that I can see is that there is an additional code file.

Always use project suppressions.