add support for __eq__ in a BaseDict

fixing #343

+ tests

Lib/defcon/objects/base.py

@@ -517,6 +517,9 @@ def _get_dict(self):
     def __hash__(self):
         return id(self)
 
+    def __eq__(self, other):
+        return id(self) == id(other)
+
     def __setitem__(self, key, value):
         oldValue = None
         if key in self:

Lib/defcon/objects/glyph.py

@@ -877,6 +877,7 @@ def insertAnchor(self, index, anchor):
         if not isinstance(anchor, self._anchorClass):
             anchor = self.instantiateAnchor(anchorDict=anchor)
 
+        assert anchor not in self._anchors
         assert anchor.glyph in (self, None), "This anchor belongs to another glyph."
 
         self.postNotification(notification="Glyph.AnchorWillBeAdded", data=dict(object=anchor))
@@ -983,7 +984,8 @@ def insertGuideline(self, index, guideline):
 
         This will post a *Glyph.Changed* notification.
         """
-        assert id(guideline) not in [id(guide) for guide in self.guidelines]
+
+        assert guideline not in self.guidelines
         if not isinstance(guideline, self._guidelineClass):
             guideline = self.instantiateGuideline(guidelineDict=guideline)
 

Lib/defcon/test/objects/test_glyph.py

@@ -481,6 +481,13 @@ def test_clearAnchors(self):
         glyph.clearAnchors()
         self.assertEqual(len(glyph.anchors), 0)
 
+    def test_duplicatedAnchors(self):
+        font = Font(getTestFontPath())
+        glyph = font["A"]
+        anchor = glyph.anchors[0]
+        with self.assertRaises(AssertionError):
+            glyph.appendAnchor(anchor)
+
     def test_appendGuideline(self):
         glyph = Glyph()
         glyph.dirty = False
@@ -504,6 +511,13 @@ def test_clearGuidelines(self):
         glyph.clearGuidelines()
         self.assertEqual(len(glyph.guidelines), 0)
 
+    def test_duplicatedGuideline(self):
+        font = Font(getTestFontPath())
+        glyph = font.layers["Layer 1"]["A"]
+        guideline = glyph.guidelines[0]
+        with self.assertRaises(AssertionError):
+            glyph.appendGuideline(guideline)
+
     def test_len(self):
         font = Font(getTestFontPath())
         glyph = font["A"]