Add tests

Note: fixers -> fixes, because of how test's `fixer_pkg` works.

my2to3/__main__.py

@@ -2,4 +2,4 @@ from lib2to3.main import main
 import sys
 
 
-sys.exit(main('my2to3.fixers'))
+sys.exit(main('my2to3.fixes'))

my2to3/tests/testFixTraceDivision.py

+from functools import partial
+from lib2to3.tests.test_fixers import FixerTestCase as lib2to3FixerTestCase
+import unittest
+
+
+class FixerTestCase(lib2to3FixerTestCase):
+  # Subclass to replace "fixer_pkg"
+  def setUp(self, fix_list=None, fixer_pkg="my2to3", options=None):
+    super(FixerTestCase, self).setUp(fix_list, fixer_pkg, options)
+
+
+class testFixTraceDivision(FixerTestCase):
+  fixer = "trace_division"
+
+  def test_simple_division(self):
+    b = """x / y"""
+    a = """division_traced(0,x , y)"""
+    self.check(b, a)
+
+  def test_nested_divisions_with_parentheses_1(self):
+    b = """(x / y) / z"""
+    a = """division_traced(1,(division_traced(0,x , y)) , z)"""
+    self.check(b, a)
+
+  def test_nested_divisions_with_parentheses_2(self):
+    b = """x / (y / z)"""
+    a = """division_traced(1,x , (division_traced(0,y , z)))"""
+    self.check(b, a)
+
+  def test_multiline_division_1(self):
+    b = """x \
+  / y"""
+    a = """  division_traced(0,x \
+  , y)"""
+    self.check(b, a)
+
+
+if __name__ == '__main__':
+  unittest.main()

setup.py

+from setuptools import setup
+
+setup(
+  name="my2to3",
+  test_suite='my2to3.tests',
+)