godot-docs/tutorials/scripting/c_sharp/diagnostics/GD0201.rst

GD0201: The name of the delegate must end with 'EventHandler'
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====================================  ======================================
                                      Value
====================================  ======================================
**Rule ID**                           GD0201
**Category**                          Usage
**Fix is breaking or non-breaking**   Breaking
**Enabled by default**                Yes
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Cause
-----

A delegate annotated with the ``[Signal]`` attribute has a name that doesn't
end with 'EventHandler'.

Rule description
----------------

Godot source generators will generate C# events using the name of the delegate
with the 'EventHandler' suffix removed. Adding the 'EventHandler' suffix to the
name of delegates used in events is a `.NET naming convention <https://learn.microsoft.com/en-us/dotnet/standard/design-guidelines/names-of-classes-structs-and-interfaces#names-of-common-types>`_.

Using a suffix for the delegate allows the generated event to use the name without
the suffix avoiding a naming conflict.

.. code-block:: csharp

    // This delegate is invalid since the name doesn't end with 'EventHandler'.
    [Signal]
    public void InvalidSignal();

    // This delegate is valid since the name ends with 'EventHandler'.
    [Signal]
    public void ValidSignalEventHandler();

Take a look at the :ref:`C# signals <doc_c_sharp_signals>` documentation for more
information about how to declare and use signals.

How to fix violations
---------------------

To fix a violation of this rule, add 'EventHandler' to the end of the delegate name.

When to suppress warnings
-------------------------

Do not suppress a warning from this rule. Signal delegates without the suffix
will be ignored by the source generator, so the signal won't be registered.