Remove deprecated rich_compare metadata

traits/tests/test_comparison_mode.py

@@ -0,0 +1,246 @@
+# (C) Copyright 2005-2022 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+import unittest
+
+from traits.api import (
+    Any,
+    cached_property,
+    ComparisonMode,
+    HasTraits,
+    Property,
+    Str,
+)
+
+
+class NoneCompare(HasTraits):
+    bar = Any(comparison_mode=ComparisonMode.none)
+
+
+class IdentityCompare(HasTraits):
+    bar = Any(comparison_mode=ComparisonMode.identity)
+
+
+class EqualityCompare(HasTraits):
+    bar = Any(comparison_mode=ComparisonMode.equality)
+
+
+class Foo(HasTraits):
+    """
+    Class implementing custom equality.
+    """
+
+    name = Str
+
+    def __eq__(self, other):
+        return self.name == other.name
+
+
+class TestComparisonMode(unittest.TestCase):
+    def setUp(self):
+        self.a = Foo(name="a")
+        self.same_as_a = Foo(name="a")
+        self.different_from_a = Foo(name="not a")
+
+    def bar_changed(self, object, trait, old, new):
+        self.changed_object = object
+        self.changed_trait = trait
+        self.changed_old = old
+        self.changed_new = new
+        self.changed_count += 1
+
+    def reset_change_tracker(self):
+        self.changed_object = None
+        self.changed_trait = None
+        self.changed_old = None
+        self.changed_new = None
+        self.changed_count = 0
+
+    def check_tracker(self, object, trait, old, new, count):
+        self.assertEqual(count, self.changed_count)
+        self.assertIs(object, self.changed_object)
+        self.assertEqual(trait, self.changed_trait)
+        self.assertIs(old, self.changed_old)
+        self.assertIs(new, self.changed_new)
+
+    def test_none_first_assignment(self):
+        nc = NoneCompare()
+        nc.on_trait_change(self.bar_changed, "bar")
+
+        self.reset_change_tracker()
+
+        default_value = nc.bar
+        nc.bar = self.a
+        self.check_tracker(nc, "bar", default_value, self.a, 1)
+
+    def test_identity_first_assignment(self):
+        ic = IdentityCompare()
+        ic.on_trait_change(self.bar_changed, "bar")
+
+        self.reset_change_tracker()
+
+        default_value = ic.bar
+        ic.bar = self.a
+        self.check_tracker(ic, "bar", default_value, self.a, 1)
+
+    def test_equality_first_assignment(self):
+        ec = EqualityCompare()
+        ec.on_trait_change(self.bar_changed, "bar")
+
+        self.reset_change_tracker()
+
+        default_value = ec.bar
+        ec.bar = self.a
+        self.check_tracker(ec, "bar", default_value, self.a, 1)
+
+    def test_none_same_object(self):
+        nc = NoneCompare()
+        nc.on_trait_change(self.bar_changed, "bar")
+
+        self.reset_change_tracker()
+
+        default_value = nc.bar
+        nc.bar = self.a
+        self.check_tracker(nc, "bar", default_value, self.a, 1)
+
+        nc.bar = self.a
+        self.check_tracker(nc, "bar", self.a, self.a, 2)
+
+    def test_identity_same_object(self):
+        ic = IdentityCompare()
+        ic.on_trait_change(self.bar_changed, "bar")
+
+        self.reset_change_tracker()
+
+        default_value = ic.bar
+        ic.bar = self.a
+        self.check_tracker(ic, "bar", default_value, self.a, 1)
+
+        ic.bar = self.a
+        self.check_tracker(ic, "bar", default_value, self.a, 1)
+
+    def test_equality_same_object(self):
+        ec = EqualityCompare()
+        ec.on_trait_change(self.bar_changed, "bar")
+
+        self.reset_change_tracker()
+
+        default_value = ec.bar
+        ec.bar = self.a
+        self.check_tracker(ec, "bar", default_value, self.a, 1)
+
+        ec.bar = self.a
+        self.check_tracker(ec, "bar", default_value, self.a, 1)
+
+    def test_none_different_object(self):
+        nc = NoneCompare()
+        nc.on_trait_change(self.bar_changed, "bar")
+
+        self.reset_change_tracker()
+
+        default_value = nc.bar
+        nc.bar = self.a
+        self.check_tracker(nc, "bar", default_value, self.a, 1)
+
+        nc.bar = self.different_from_a
+        self.check_tracker(nc, "bar", self.a, self.different_from_a, 2)
+
+    def test_identity_different_object(self):
+        ic = IdentityCompare()
+        ic.on_trait_change(self.bar_changed, "bar")
+
+        self.reset_change_tracker()
+
+        default_value = ic.bar
+        ic.bar = self.a
+        self.check_tracker(ic, "bar", default_value, self.a, 1)
+
+        ic.bar = self.different_from_a
+        self.check_tracker(ic, "bar", self.a, self.different_from_a, 2)
+
+    def test_equality_different_object(self):
+        ec = EqualityCompare()
+        ec.on_trait_change(self.bar_changed, "bar")
+
+        self.reset_change_tracker()
+
+        default_value = ec.bar
+        ec.bar = self.a
+        self.check_tracker(ec, "bar", default_value, self.a, 1)
+
+        ec.bar = self.different_from_a
+        self.check_tracker(ec, "bar", self.a, self.different_from_a, 2)
+
+    def test_none_different_object_same_as(self):
+        nc = NoneCompare()
+        nc.on_trait_change(self.bar_changed, "bar")
+
+        self.reset_change_tracker()
+
+        default_value = nc.bar
+        nc.bar = self.a
+        self.check_tracker(nc, "bar", default_value, self.a, 1)
+
+        nc.bar = self.same_as_a
+        self.check_tracker(nc, "bar", self.a, self.same_as_a, 2)
+
+    def test_identity_different_object_same_as(self):
+        ic = IdentityCompare()
+        ic.on_trait_change(self.bar_changed, "bar")
+
+        self.reset_change_tracker()
+
+        default_value = ic.bar
+        ic.bar = self.a
+        self.check_tracker(ic, "bar", default_value, self.a, 1)
+
+        ic.bar = self.same_as_a
+        self.check_tracker(ic, "bar", self.a, self.same_as_a, 2)
+
+    def test_equality_different_object_same_as(self):
+        ec = EqualityCompare()
+        ec.on_trait_change(self.bar_changed, "bar")
+
+        self.reset_change_tracker()
+
+        default_value = ec.bar
+        ec.bar = self.a
+        self.check_tracker(ec, "bar", default_value, self.a, 1)
+
+        # Values of a and same_as_a are the same and should therefore not
+        # be considered a change.
+        ec.bar = self.same_as_a
+        self.check_tracker(ec, "bar", default_value, self.a, 1)
+
+    def test_comparison_mode_none_with_cached_property(self):
+        # Even though the property is cached such that old value equals new
+        # value, its change event is tied to the dependent.
+
+        class Model(HasTraits):
+            value = Property(depends_on="name")
+            name = Str(comparison_mode=ComparisonMode.none)
+
+            @cached_property
+            def _get_value(self):
+                return self.trait_names
+
+        instance = Model()
+        events = []
+        instance.on_trait_change(lambda: events.append(None), "value")
+
+        instance.name = "A"
+
+        events.clear()
+
+        # when
+        instance.name = "A"
+
+        # then
+        self.assertEqual(len(events), 1)