CA1510: Use ArgumentNullException throw helper

Property	Value
Rule ID	CA1510
Title	Use ArgumentNullException throw helper
Category	Maintainability
Fix is breaking or non-breaking	Non-Breaking
Enabled by default in .NET 9	As suggestion

Cause

Code checks whether an argument is null and then conditionally throws an ArgumentNullException.

Rule description

Argument checks have a substantial impact on code size and often dominate the code for small functions and property setters. These checks prevent inlining and cause substantial instruction-cache pollution. Throw-helper methods such as ArgumentNullException.ThrowIfNull are simpler and more efficient than if blocks that construct a new exception instance.

Example

The following code snippet shows a violation of CA1510:

void M(string arg)
{
    if (arg is null)
        throw new ArgumentNullException(nameof(arg));
}

The following code snippet shows the fix:

void M(string arg)
{
    ArgumentNullException.ThrowIfNull(arg);
}

How to fix violations

Replace the if block that throws the exception with a call to ArgumentNullException.ThrowIfNull. Or, in Visual Studio, use the lightbulb menu to fix your code automatically.

When to suppress warnings

It's safe to suppress a violation of this rule if you're not concerned about the maintainability of your code. It is also fine to suppress violations that are identified to be false positives.

Suppress a warning

If you just want to suppress a single violation, add preprocessor directives to your source file to disable and then re-enable the rule.

#pragma warning disable CA1510
// The code that's violating the rule is on this line.
#pragma warning restore CA1510

To disable the rule for a file, folder, or project, set its severity to none in the configuration file.

[*.{cs,vb}]
dotnet_diagnostic.CA1510.severity = none

For more information, see How to suppress code analysis warnings.