tests: use math.isclose to compare float coordinates

using the default tolerance which is 1e-9, i.e. assures that two floats are the same
within about 9 decimal digits

https://docs.python.org/3/library/math.html#math.isclose

tests/pens_test.py

@@ -38,7 +38,7 @@ class _TestPenMixin(object):
     def expect_glyph(self, source, expected):
         converted = self.convert_glyph(source)
         self.assertNotEqual(converted, source)
-        if converted != expected:
+        if not converted.approx(expected):
             print(self.diff(expected, converted))
             self.fail("converted glyph is different from expected")
 

tests/utils.py

@@ -1,6 +1,7 @@
 from __future__ import print_function, division, absolute_import
 from . import CUBIC_GLYPHS
 from ufoLib.pointPen import PointToSegmentPen, SegmentToPointPen
+from fontTools.misc.py23 import isclose
 import unittest
 
 
@@ -111,6 +112,34 @@ class DummyGlyph(object):
         """Return True if 'other' glyph's outline is different from self."""
         return not (self == other)
 
+    def approx(self, other):
+        if hasattr(other, 'outline'):
+            outline2 == other.outline
+        elif hasattr(other, 'draw'):
+            outline2 = self.__class__(other).outline
+        else:
+            raise TypeError(type(other).__name__)
+        outline1 = self.outline
+        if len(outline1) != len(outline2):
+            return False
+        for (cmd1, arg1, kwd1), (cmd2, arg2, kwd2) in zip(outline1, outline2):
+            if cmd1 != cmd2:
+                return False
+            if kwd1 != kwd2:
+                return False
+            if arg1:
+                if isinstance(arg1[0], tuple):
+                    if not arg2 or not isinstance(arg2[0], tuple):
+                        return False
+                    for (x1, y1), (x2, y2) in zip(arg1, arg2):
+                        if not isclose(x1, x2) or not isclose(y1, y2):
+                            return False
+                elif arg1 != arg2:
+                    return False
+            elif arg2:
+                return False
+        return True
+
     def __str__(self):
         """Return commands making up the glyph's outline as a string."""
         return str(self._pen)