How can I make Code Contracts ignore a specific assembly reference?

Question

I'm making an extension to Visual Studio. Within the code I'm using Code Contracts to make assertions and checks. I set the warning option level to high.

What I would like to do is maintain that warning level while ignoring any checks made on EnvDTE references.

Consider the following code example:

public static string GetAbsoluteOutputFolder(EnvDTE.Project project) {     if (project == null) throw new ArgumentNullException("project");      var path =         project.ConfigurationManager.ActiveConfiguration.Properties.Item("OutputPath").Value.ToString();     //... } 

With my current settings, CC would require me to add the following checks before assigning the path variable:

Contract.Assume(project.ConfigurationManager != null); Contract.Assume(project.ConfigurationManager.ActiveConfiguration != null); Contract.Assume(project.ConfigurationManager.ActiveConfiguration.Properties != null); 

Therefore what I'd like to do here is to tell CC to "trust" EnvDTE and ignore these types and their properties.

I thought the "Be optimistic on external API" CC option served this very purpose; turns out it doesn't.

Is there a way to make it behave the way I want that would not require a lower warning level?

EDIT: I want a solution that would work at project level and that would still allow "regular" checks to be performed.

Answer 1

Can´t provide a detailed solution but this should be solvable by using either the Baseline Feature or System.Diagnostics.CodeAnalysis.SuppressMessage on assembly level:

[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Contracts", "Whatever")] 

You can use the "Target" Property of the SuppressMessageAttribute to only ignore the Message on specific Types / Methods / Namespaces:

[SuppressMessage("Microsoft.Contracts",                   "CC1055",                   Scope="Member",                   Target="YouNamespace.EnvDTE.Project")] 

Note that the Parameters i used are just a good bet, you´ll have to figure out the correct Scope, MessageId and Target yourself :) On a sidenote, i think the Attribute is Conditional("CODE_ANALYSIS").

The official suggested solution to this problem is to create some sort of wrapper, in your case probably a repository that would create or contain your EnvDTE.Project objects. Then you can add the required Contract.Ensures there.