1 files changed, 47 insertions, 0 deletions
diff --git a/Lib/test/test_int.py b/Lib/test/test_int.py
index 625c388cd9..f484c59f67 100644
--- a/Lib/test/test_int.py
+++ b/Lib/test/test_int.py
@@ -795,5 +795,52 @@ class IntSubclassStrDigitLimitsTests(IntStrDigitLimitsTests):
     int_class = IntSubclass
 
 
+class PyLongModuleTests(unittest.TestCase):
+    # Tests of the functions in _pylong.py.  Those get used when the
+    # number of digits in the input values are large enough.
+
+    def setUp(self):
+        super().setUp()
+        self._previous_limit = sys.get_int_max_str_digits()
+        sys.set_int_max_str_digits(0)
+
+    def tearDown(self):
+        sys.set_int_max_str_digits(self._previous_limit)
+        super().tearDown()
+
+    def test_pylong_int_to_decimal(self):
+        n = (1 << 100_000) - 1
+        suffix = '9883109375'
+        s = str(n)
+        assert s[-10:] == suffix
+        s = str(-n)
+        assert s[-10:] == suffix
+        s = '%d' % n
+        assert s[-10:] == suffix
+        s = b'%d' % n
+        assert s[-10:] == suffix.encode('ascii')
+
+    def test_pylong_int_divmod(self):
+        n = (1 << 100_000)
+        a, b = divmod(n*3 + 1, n)
+        assert a == 3 and b == 1
+
+    def test_pylong_str_to_int(self):
+        v1 = 1 << 100_000
+        s = str(v1)
+        v2 = int(s)
+        assert v1 == v2
+        v3 = int(' -' + s)
+        assert -v1 == v3
+        v4 = int(' +' + s + ' ')
+        assert v1 == v4
+        with self.assertRaises(ValueError) as err:
+            int(s + 'z')
+        with self.assertRaises(ValueError) as err:
+            int(s + '_')
+        with self.assertRaises(ValueError) as err:
+            int('_' + s)
+
+
 if __name__ == "__main__":
     unittest.main()