URI Return String

ID

csharp.uri_return_string

Severity

low

Remediation Complexity

medium

Remediation Risk

low

Remediation Effort

medium

Resource

Code Smell

Language

CSharp

Tags

api-design, code_smell, uri

Description

Reports methods whose name ends with Url or Uri and whose return type is string. The .NET design guidelines recommend exposing URLs as System.Uri values rather than raw strings: the type captures parsing, distinguishes opaque URI from arbitrary text, and lets the caller reject malformed input early.

Rationale

Uri is the strongly-typed contract for URLs in .NET. Returning a raw string forces every consumer to call new Uri(…​) again — duplicating the parse work and burying the failure mode in the consumer instead of the producer. APIs that return Uri make malformed inputs impossible by construction.

public class Catalog
{
    public string GetProductUrl(int id) =>                              // FLAW
        $"https://api.example.com/products/{id}";

    public Uri GetProductUri(int id) =>                                 // OK
        new Uri($"https://api.example.com/products/{id}");
}

Remediation

Change the return type to System.Uri and construct the value inside the method. If callers genuinely need a string, expose a separate property Uri.AbsoluteUri on the returned value or keep the string method with a name that does not end with Url/Uri.

References