ForbidFullyQualifiedTypeReferences

Diagnostic Rule Overview

Field	Value
ID	SHIMMER2040
Analyzer title	Avoid fully-qualified type references
Analyzer message	Type reference '0' should not be fully-qualified; add 'using 1;' instead
Code fix title	Use using directive and simplify type name
Default severity	Info
Minimum framework/language version	N/A
Category	ShimmeringStyle
Link to code	ForbidFullyQualifiedTypeReferencesAnalyzer.cs
Code fix exists?	Yes

Detailed Explanation

Using fully-qualified type references in C# expressions and type syntax clutter the code and make it harder to read. This analyzer forbids fully-qualified type references when their containing namespace is not already in scope, requiring developers to add a using directive instead and use the simplified type name.

Unlike Microsoft's IDE0001 (Simplify Name), this analyzer fires only when the required using directive does not yet exist in the file (either locally or globally), and its code fix automatically inserts the necessary using directive.

Examples

Flagged code:

namespace Tests
{
    class Test
    {
        void Method()
        {
            System.Text.Encoding.UTF8.GetBytes("test");
        }
    }
}

Fixed code:

using System.Text;

namespace Tests
{
    class Test
    {
        void Method()
        {
            Encoding.UTF8.GetBytes("test");
        }
    }
}

Justification of the Severity

This rule is a style suggestion designed to keep C# code clean and uniform by avoiding verbose type paths. Because it is purely cosmetic and does not affect correctness or performance, its default severity is Info.

When to Suppress

Suppress this diagnostic if you explicitly want to keep type names fully qualified to prevent potential naming confusion or conflicts, or if you prefer using fully-qualified names in a particular file.