GD0108: The exported tool button is not in a tool class
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                                      Value
====================================  ======================================
**Rule ID**                           GD0108
**Category**                          Usage
**Fix is breaking or non-breaking**   Non-breaking
**Enabled by default**                Yes
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Cause
-----

A property is annotated with the ``[ExportToolButton]`` attribute in a class that
is **not** annotated with the ``[Tool]`` attribute.

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

The ``[ExportToolButton]`` is used to create clickable buttons in the inspector so,
like every other script that runs in the editor, it needs to be annotated with the
``[Tool]`` attribute.

.. code-block:: csharp
    :emphasize-lines: 1

    [Tool]
    public partial class MyNode : Node
    {
        [ExportToolButton("Click me!")]
        public Callable ClickMeButton => Callable.From(ClickMe);

        private static void ClickMe()
        {
            GD.Print("Hello world!");
        }
    }

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

To fix a violation of this rule, add the ``[Tool]`` attribute to the class that
contains the member annotated with the ``[ExportToolButton]`` attribute.

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

Do not suppress a warning from this rule. The clickable buttons in the inspector
won't be functional if their script is not annotated with the ``[Tool]`` attribute.