From 28bfe768d8066b9b42d5e9081ba7318ae7ca5fbe Mon Sep 17 00:00:00 2001
From: Sander Land <48946947+sanderland@users.noreply.github.com>
Date: Thu, 20 May 2021 09:40:59 +0200
Subject: [PATCH] EventDispatcher: Add nicer error message for non-existing
 properties (#7536)

* nicer error message for unknown properties

* edit kivy/tests/test_widget.py

* edit kivy/_event.pyx

* edit kivy/_event.pyx, edit kivy/tests/test_widget.py

* edit kivy/_event.pyx

* edit kivy/_event.pyx

* edit kivy/tests/test_widget.py, edit kivy/_event.pyx

* edit kivy/tests/test_widget.py

* edit kivy/tests/test_widget.py

* edit kivy/_event.pyx

* more tests

* test

* test

* edit kivy/_event.pyx

* move tests

* fix ALL the things

* Update kivy/_event.pyx

Co-authored-by: matham <matt@einhorn.dev>

* edit kivy/_event.pyx

* pytestify

* remove kivy/graphics/cgl.h

* edit kivy/tests/test_properties.py

* edit kivy/tests/test_properties.py, edit kivy/_event.pyx

* typeerror

* fix

Co-authored-by: matham <matt@einhorn.dev>
---
 kivy/_event.pyx               | 14 +++++++-
 kivy/tests/test_properties.py | 64 +++++++++++++++++++++++++++++++++++
 2 files changed, 77 insertions(+), 1 deletion(-)

diff --git a/kivy/_event.pyx b/kivy/_event.pyx
index 344f0c36c..ca6a073e8 100644
--- a/kivy/_event.pyx
+++ b/kivy/_event.pyx
@@ -228,7 +228,19 @@ cdef class EventDispatcher(ObjectWithUid):
         prop_args = {
             k: kwargs.pop(k) for k in list(kwargs.keys()) if k in properties}
         self._kwargs_applied_init = set(prop_args.keys()) if prop_args else set()
-        super(EventDispatcher, self).__init__(**kwargs)
+
+        # at this point any kwargs passed may go to object
+        # which will raise a TypeError and cause confusion
+        try:
+           super(EventDispatcher, self).__init__(**kwargs)
+        except TypeError as e:
+           if kwargs and str(e).startswith("object.__init__() takes"):
+               raise TypeError(
+                  'Properties {} passed to __init__ may not be existing '
+                  'property names. Valid properties are {}'.format(
+                      sorted(kwargs.keys()), sorted(properties.keys()))) from e
+           else:
+               raise
 
         __cls__ = self.__class__
         if __cls__ not in cache_events_handlers:
diff --git a/kivy/tests/test_properties.py b/kivy/tests/test_properties.py
index b444b4610..9e215d645 100644
--- a/kivy/tests/test_properties.py
+++ b/kivy/tests/test_properties.py
@@ -1266,3 +1266,67 @@ def test_inherit_property():
     event.b = 'goodbye'
     assert event.b == 'goodbye'
     assert args == (event, 'goodbye')
+
+
+def test_unknown_property():
+    from kivy.properties import NumericProperty
+
+    class MyWidget(EventDispatcher):
+        width = NumericProperty(0)
+
+    with pytest.raises(TypeError) as cm:
+        MyWidget(width=12, unkn="abc")
+    assert "Properties ['unkn'] passed to __init__ may not be existing " \
+           "property names. Valid properties are ['width']" \
+           == str(cm.value)
+
+
+def test_known_property_multiple_inheritance():
+
+    class Behavior:
+        def __init__(self, name):
+            print(f'Behavior: {self}, name={name}')
+            super().__init__()
+
+    class Widget2(Behavior, EventDispatcher):
+        pass
+
+    class Widget3(EventDispatcher, Behavior):
+        pass
+
+    with pytest.raises(TypeError) as cm:
+        EventDispatcher(name='Pasta')
+    assert "Properties ['name'] passed to __init__ may not be existing" \
+           in str(cm.value)
+
+    Widget2(name='Pasta')  # does not raise a ValueError
+    Widget3(name='Pasta')  # does not raise a ValueError
+
+
+def test_pass_other_typeerror():
+
+    class Behavior:
+        def __init__(self, name):
+            super().__init__()
+            raise TypeError("this is a typeerror unrelated to object")
+
+    class Widget2(Behavior, EventDispatcher):
+        pass
+
+    class Widget3(EventDispatcher, Behavior):
+        pass
+
+    for cls in [Widget2, Widget3]:
+        with pytest.raises(TypeError) as cm:
+            cls(name='Pasta')
+        assert "this is a typeerror unrelated to object" == str(cm.value)
+
+
+def test_object_init_error():  # the above 3 test rely on this
+    class TestCls(object):
+        def __init__(self, **kwargs):
+            super(TestCls, self).__init__(**kwargs)
+
+    with pytest.raises(TypeError) as cm:
+        TestCls(name='foo')
+    assert str(cm.value).startswith("object.__init__() takes")