1 files changed, 46 insertions, 1 deletions
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index d5eec7c..555ad74 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -32,7 +32,7 @@ import time
 import unittest
 import warnings
 import weakref
-from collections import deque
+from collections import deque, UserList
 from itertools import cycle, count
 from test import support
 
@@ -1193,6 +1193,29 @@ class BufferedWriterTest(unittest.TestCase, CommonBufferedTests):
         bufio.flush()
         self.assertEqual(b"abc", writer._write_stack[0])
 
+    def test_writelines(self):
+        l = [b'ab', b'cd', b'ef']
+        writer = self.MockRawIO()
+        bufio = self.tp(writer, 8)
+        bufio.writelines(l)
+        bufio.flush()
+        self.assertEqual(b''.join(writer._write_stack), b'abcdef')
+
+    def test_writelines_userlist(self):
+        l = UserList([b'ab', b'cd', b'ef'])
+        writer = self.MockRawIO()
+        bufio = self.tp(writer, 8)
+        bufio.writelines(l)
+        bufio.flush()
+        self.assertEqual(b''.join(writer._write_stack), b'abcdef')
+
+    def test_writelines_error(self):
+        writer = self.MockRawIO()
+        bufio = self.tp(writer, 8)
+        self.assertRaises(TypeError, bufio.writelines, [1, 2, 3])
+        self.assertRaises(TypeError, bufio.writelines, None)
+        self.assertRaises(TypeError, bufio.writelines, 'abc')
+
     def test_destructor(self):
         writer = self.MockRawIO()
         bufio = self.tp(writer, 8)
@@ -2296,6 +2319,28 @@ class TextIOWrapperTest(unittest.TestCase):
             reads += c
         self.assertEqual(reads, "A"*127+"\nB")
 
+    def test_writelines(self):
+        l = ['ab', 'cd', 'ef']
+        buf = self.BytesIO()
+        txt = self.TextIOWrapper(buf)
+        txt.writelines(l)
+        txt.flush()
+        self.assertEqual(buf.getvalue(), b'abcdef')
+
+    def test_writelines_userlist(self):
+        l = UserList(['ab', 'cd', 'ef'])
+        buf = self.BytesIO()
+        txt = self.TextIOWrapper(buf)
+        txt.writelines(l)
+        txt.flush()
+        self.assertEqual(buf.getvalue(), b'abcdef')
+
+    def test_writelines_error(self):
+        txt = self.TextIOWrapper(self.BytesIO())
+        self.assertRaises(TypeError, txt.writelines, [1, 2, 3])
+        self.assertRaises(TypeError, txt.writelines, None)
+        self.assertRaises(TypeError, txt.writelines, b'abc')
+
     def test_issue1395_1(self):
         txt = self.TextIOWrapper(self.BytesIO(self.testdata), encoding="ascii")