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C#

C# static code analysis

Unique rules to find Bugs, Vulnerabilities, Security Hotspots, and Code Smells in your C# code

  • All rules 493
  • Vulnerability46
  • Bug88
  • Security Hotspot24
  • Code Smell335

  • Quick Fix 61
Filtered: 12 rules found
design
    Impact
      Clean code attribute
        1. Interfaces for durable entities should satisfy the restrictions

           Code Smell
        2. Client instances should not be recreated on each Azure Function invocation

           Code Smell
        3. Multidimensional arrays should not be used

           Code Smell
        4. Strings or integral types should be used for indexers

           Code Smell
        5. Classes should not have only "private" constructors

           Bug
        6. Interfaces should not simply inherit from base interfaces with colliding members

           Code Smell
        7. Methods should not return values that are never used

           Code Smell
        8. Inner class members should not shadow outer class "static" or type members

           Code Smell
        9. "interface" instances should not be cast to concrete types

           Code Smell
        10. Two branches in a conditional structure should not have exactly the same implementation

           Code Smell
        11. String literals should not be duplicated

           Code Smell
        12. Utility classes should not have public constructors

           Code Smell

        Interfaces should not simply inherit from base interfaces with colliding members

        intentionality - clear
        maintainability
        Code Smell
        • design

        Why is this an issue?

        When an interface inherits from two interfaces that both define a member with the same name, trying to access that member through the derived interface will result in the compiler error CS0229 Ambiguity between 'IBase1.SomeProperty' and 'IBase2.SomeProperty'.

        So instead, every caller will be forced to cast instances of the derived interface to one or the other of its base interfaces to resolve the ambiguity and be able to access the member. Instead, it is better to resolve the ambiguity in the definition of the derived interface either by:

        • renaming the member in one of the base interfaces to remove the collision
        • also defining that member in the derived interface. Use this only if all copies of the member are meant to hold the same value.

        Noncompliant code example

        public interface IBase1
        {
          string SomeProperty { get; set; }
        }
        
        public interface IBase2
        {
          string SomeProperty { get; set; }
        }
        
        public interface IDerived : IBase1, IBase2 // Noncompliant, accessing IDerived.SomeProperty is ambiguous
        {
        }
        
        public class MyClass : IDerived
        {
          // Implements both IBase1.SomeProperty and IBase2.SomeProperty
          public string SomeProperty { get; set; } = "Hello";
        
          public static void Main()
          {
            MyClass myClass = new MyClass();
            Console.WriteLine(myClass.SomeProperty); // Writes "Hello" as expected
            Console.WriteLine(((IBase1)myClass).SomeProperty); // Writes "Hello" as expected
            Console.WriteLine(((IBase2)myClass).SomeProperty); // Writes "Hello" as expected
            Console.WriteLine(((IDerived)myClass).SomeProperty); // Error CS0229 Ambiguity between 'IBase1.SomeProperty' and 'IBase2.SomeProperty'
          }
        }
        

        Compliant solution

        public interface IDerived : IBase1, IBase2
        {
          new string SomeProperty { get; set; }
        }
        
        public class MyClass : IDerived
        {
          // Implements IBase1.SomeProperty, IBase2.SomeProperty and IDerived.SomeProperty
          public string SomeProperty { get; set; } = "Hello";
        
          public static void Main()
          {
            MyClass myClass = new MyClass();
            Console.WriteLine(myClass.SomeProperty); // Writes "Hello" as expected
            Console.WriteLine(((IBase1)myClass).SomeProperty); // Writes "Hello" as expected
            Console.WriteLine(((IBase2)myClass).SomeProperty); // Writes "Hello" as expected
            Console.WriteLine(((IDerived)myClass).SomeProperty); // Writes "Hello" as expected
          }
        }
        

        or

        public interface IBase1
        {
          string SomePropertyOne { get; set; }
        }
        
        public interface IBase2
        {
          string SomePropertyTwo { get; set; }
        }
        
        public interface IDerived : IBase1, IBase2
        {
        }
        
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          Developer Edition
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