This pull request introduces a new analyzer rule, ECS0008, which is designed to enforce the use of the null-conditional operator when invoking event handlers in C#. This practice helps prevent potential NullReferenceExceptions, improving the safety and robustness of the code.
Key Features:
Detection of Potential Violations: The rule identifies patterns where an event handler is invoked without using the null-conditional operator (?.Invoke), such as direct invocations or invocations within an if statement checking for null.
Automatic Code Fixes: The code fix provider automatically replaces the identified pattern with the null-conditional operator, ensuring that the event handler is only invoked when it has subscribers.
Comprehensive Coverage: The rule handles cases where the event handler is checked directly and cases where it is first assigned to a local variable.
Example Violation:
public class EventSource
{
private EventHandler<int> Updated;
private int counter;
public void RaiseUpdates()
{
counter++;
if (Updated != null)
Updated(this, counter);
}
}
Fixed code:
public class EventSource
{
private EventHandler<int> Updated;
private int counter;
public void RaiseUpdates()
{
counter++;
Updated?.Invoke(this, counter);
}
}
This pull request introduces a new analyzer rule, ECS0008, which is designed to enforce the use of the null-conditional operator when invoking event handlers in C#. This practice helps prevent potential
NullReferenceExceptions
, improving the safety and robustness of the code.Key Features:
?.Invoke
), such as direct invocations or invocations within anif
statement checking fornull
.Example Violation:
Fixed code: