Use approximate floating point comparison in tests

Allow minor floating point differences when comparing glyph digests.
This ensures tests pass with both older fonttools versions (which had
floating point drift in splitCubicAtT) and newer versions (which force
exact endpoint matching).

Uses math.isclose for float comparison within a recursive helper that
handles the nested digest structure.

Author: anthrotype

tests/test_BooleanGlyph.py

@@ -1,7 +1,8 @@
 from __future__ import print_function, division, absolute_import
 
-import sys
+import math
 import os
+import sys
 import unittest
 
 import pytest
@@ -14,6 +15,23 @@
 VERBOSE = False
 
 
+def _approx_equal(a, b):
+    """Check if two values are approximately equal, handling nested structures.
+
+    Uses math.isclose for float comparison to handle minor differences between
+    fonttools versions in splitCubicAtT precision.
+    """
+    if type(a) != type(b):
+        return False
+    if isinstance(a, (tuple, list)):
+        if len(a) != len(b):
+            return False
+        return all(_approx_equal(x, y) for x, y in zip(a, b))
+    if isinstance(a, float):
+        return math.isclose(a, b)
+    return a == b
+
+
 class BooleanTests(unittest.TestCase):
 
     pass
@@ -47,7 +65,10 @@ def test(self):
         func(*args, outPen=testPen)
         expectedPen = DigestPointPen()
         expectedGlyph.drawPoints(expectedPen)
-        self.assertEqual(testPen.getDigest(), expectedPen.getDigest(), "Glyph name '%s' failed for '%s'." % (glyph.name, booleanMethodName))
+        self.assertTrue(
+            _approx_equal(testPen.getDigest(), expectedPen.getDigest()),
+            "Glyph name '%s' failed for '%s'." % (glyph.name, booleanMethodName)
+        )
 
     return True, test