Fix working with async functions in the diff parser, fixes #56

test/test_diff_parser.py

@@ -1267,3 +1267,20 @@ def test_x(differ):
     differ.parse(code2, copies=ANY, parsers=ANY, expect_error_leaves=True)
     differ.parse(code3, copies=ANY, parsers=ANY, expect_error_leaves=True)
     differ.parse(code1, copies=1)
+
+
+@pytest.mark.skipif(sys.version_info < (3, 5), reason="Async starts working in 3.5")
+def test_async_copy(differ):
+    code1 = dedent('''\
+        async def main():
+            x = 3
+            print(
+        ''')
+    code2 = dedent('''\
+        async def main():
+            x = 3
+            print()
+        ''')
+    differ.initialize(code1)
+    differ.parse(code2, copies=1, parsers=1)
+    differ.parse(code1, copies=1, parsers=1, expect_error_leaves=True)