Type of issue

Missing information

Description

The following compiler warning is not reflected in the documentation.

warning CA2208: Method Foo passes 'bar' as the paramName argument to a ArgumentNullException constructor. Replace this argument with one of the method's parameter names. Note that the provided parameter name should have the exact casing as declared on the method. (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca2208)

Example:

public void DoFoo(Foo foo) {
    Bar? bar = foo.Bar;
    if (bar is null) throw new ArgumentNullException(nameof(bar), $"Foo named {foo.Name} had no Bar!"); // CA2208
}

The documentation says a lot about not mixing up the parameter name with the message, but doesn't say anything about the parameter name needing to match a method parameter.

Attempting to use NullReferenceException results in CA2201. I'm left wondering what to do if I want to raise an exception when some non-parameter variable is null.

Page URL

https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/quality-rules/ca2208

Content source URL

https://github.com/dotnet/docs/blob/main/docs/fundamentals/code-analysis/quality-rules/ca2208.md

Document Version Independent Id

cc2b5015-89a9-02ff-a585-fca3449dfa9a

Platform Id

09de10c1-92b4-8a2d-2ff4-db0e71226d62

Article author

@gewarren

Metadata

• ID: ff82be90-2d17-5880-4edd-a89b18a3ae2b
• PlatformId: 09de10c1-92b4-8a2d-2ff4-db0e71226d62
• Service: dotnet-fundamentals

Related Issues

Associated WorkItem - 502087