rspec/rules/S3059/csharp/rule.adoc

== Why is this an issue?

There's no point in having a ``++public++`` member in a non-``++public++`` type because objects that can't access the type will never have the chance to access the member.


This rule raises an issue when a type has methods, fields, or inner types with higher visibility than the type itself has.


=== Noncompliant code example

[source,csharp]
----
internal class MyClass
{
    public static decimal PI = 3.14m;  // Noncompliant

    public int GetOne() // Noncompliant
    {
        return 1;
    }

    protected record NestedType // Noncompliant: outer class is internal
    {
        public bool FlipCoin() // Noncompliant: outer class is internal
        {
            return false;
        }
        // ...
    }
}
----


=== Compliant solution

[source,csharp]
----
public class MyClass // Class visibility upgrade makes members compliant
{
    public static decimal PI = 3.14m;

    public int GetOne()
    {
        return 1;
    }

    protected record NestedType
    {
        public bool FlipCoin() // Outer type is public
        {
            return false;
        }
        // ...
    }
}
----


=== Exceptions

User defined operators need to be public:

[source,csharp]
----
public static implicit operator byte(MyClass a) => 1; // Compliant
public static explicit operator MyClass(byte a) => new MyClass(a); // Compliant
----

Nested types, even if private, can be used and inherited in the parent type. In this case, the visibility of the outer type is considered.

[source,csharp]
----
internal class MyClass
{
    private class NestedClass
    {
        public int PublicProperty { get; } // Noncompliant: should be internal
        protected internal int ProtectedInternalProperty { get; } // Compliant: can be used in `InternalsVisibleTo` assemblies
        internal int InternalProperty { get; } // Compliant: can be used in `InternalsVisibleTo` assemblies
        protected int ProtectedProperty { get; } // Compliant: can be used in derived type
        private protected int PrivateProtectedProperty { get; } // Compliant: can be used in derived type
        private int PrivateProperty { get; }
    }
}
----


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== Implementation Specification
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include::../message.adoc[]

'''
== Comments And Links
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include::../comments-and-links.adoc[]

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