Attribute classes should be sealed

Rule ND1310 Design

How to fix

CQLinq source

This rule is written in CQLinq, C# LINQ over the NDepend code model. It ships with every new NDepend project: you can read it, adapt it, or use it as a starting point for your own custom rules.

// <Name>Attribute classes should be sealed</Name>
// <Id>ND1310:AttributeClassesShouldBeSealed</Id>

warnif count > 0 from t in Application.Types where 
  t.IsAttributeClass && 
 !t.IsSealed && 
 !t.IsAbstract && 
  t.IsPublic
select new {
   t, 
   t.NbLinesOfCode,
   Debt = 2.ToMinutes().ToDebt(),
   Severity = Severity.Medium
} 

//<Expl>
// To potentially enhance the performance of .NET 
// methods designed for custom attributes, it is 
// advisable to seal the attribute *{0}*.
//</Expl>

//<Desc>
// .NET methods fetching custom attributes (like
// *System.Attribute.GetCustomAttribute()*) explore the attribute inheritance
// hierarchy by default. Sealing the attribute removes that search,
// potentially enhancing performance.
//</Desc>

//<HowToFix>
// Seal the attribute type or make it abstract.
//</HowToFix>

Open in the interactive Rules Explorer · All default rules

Design: all 16 items

• Avoid custom delegates ND1300
• Types with disposable instance fields must be disposable ND1301
• Disposable types with unmanaged resources should declare finalizer ND1302
• Methods that create disposable object(s) and that don't call Dispose() ND1303
• Disposable Types Must Unsubscribe Events ND1315
• Classes that are candidate to be turned into structures ND1304
• Avoid namespaces with few types ND1305
• Nested types should not be visible ND1306
• Declare types in namespaces ND1307
• Empty static constructor can be discarded ND1308
• Instances size shouldn't be too big ND1309
• Attribute classes should be sealed ND1310
• Don't use obsolete types, methods or fields ND1311
• Do implement methods that throw NotImplementedException ND1312
• Override equals and operator equals on value types ND1313
• Boxing/unboxing should be avoided ND1314