Code inspection: Parameter can be declared with the base type

This inspection reports a method parameter declared as a concrete type even though the method only uses it through a base type or interface. Using the less specific type makes the API more flexible without changing the method's behavior.

Example

                interface IFoo
                {
                    void Run();
                }
                class Foo : IFoo
                {
                    public void Run() { }
                }
                class C
                {
                    private static void Execute(Foo foo)
                    {
                        foo.Run();
                    }
                }
            

                interface IFoo
                {
                    void Run();
                }
                class Foo : IFoo
                {
                    public void Run() { }
                }
                class C
                {
                    private static void Execute(IFoo foo)
                    {
                        foo.Run();
                    }
                }
            

Quick-fix

Change the parameter type to the suggested base type or interface.

29 March 2026