1 files changed, 95 insertions, 0 deletions
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index 1cf97dd2e6..bda59bb356 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -943,6 +943,71 @@ class BufferedReaderTest(unittest.TestCase, CommonBufferedTests):
         self.assertEqual(bufio.readinto(b), 1)
         self.assertEqual(b, b"cb")
 
+    def test_readinto1(self):
+        buffer_size = 10
+        rawio = self.MockRawIO((b"abc", b"de", b"fgh", b"jkl"))
+        bufio = self.tp(rawio, buffer_size=buffer_size)
+        b = bytearray(2)
+        self.assertEqual(bufio.peek(3), b'abc')
+        self.assertEqual(rawio._reads, 1)
+        self.assertEqual(bufio.readinto1(b), 2)
+        self.assertEqual(b, b"ab")
+        self.assertEqual(rawio._reads, 1)
+        self.assertEqual(bufio.readinto1(b), 1)
+        self.assertEqual(b[:1], b"c")
+        self.assertEqual(rawio._reads, 1)
+        self.assertEqual(bufio.readinto1(b), 2)
+        self.assertEqual(b, b"de")
+        self.assertEqual(rawio._reads, 2)
+        b = bytearray(2*buffer_size)
+        self.assertEqual(bufio.peek(3), b'fgh')
+        self.assertEqual(rawio._reads, 3)
+        self.assertEqual(bufio.readinto1(b), 6)
+        self.assertEqual(b[:6], b"fghjkl")
+        self.assertEqual(rawio._reads, 4)
+
+    def test_readinto_array(self):
+        buffer_size = 60
+        data = b"a" * 26
+        rawio = self.MockRawIO((data,))
+        bufio = self.tp(rawio, buffer_size=buffer_size)
+
+        # Create an array with element size > 1 byte
+        b = array.array('i', b'x' * 32)
+        assert len(b) != 16
+
+        # Read into it. We should get as many *bytes* as we can fit into b
+        # (which is more than the number of elements)
+        n = bufio.readinto(b)
+        self.assertGreater(n, len(b))
+
+        # Check that old contents of b are preserved
+        bm = memoryview(b).cast('B')
+        self.assertLess(n, len(bm))
+        self.assertEqual(bm[:n], data[:n])
+        self.assertEqual(bm[n:], b'x' * (len(bm[n:])))
+
+    def test_readinto1_array(self):
+        buffer_size = 60
+        data = b"a" * 26
+        rawio = self.MockRawIO((data,))
+        bufio = self.tp(rawio, buffer_size=buffer_size)
+
+        # Create an array with element size > 1 byte
+        b = array.array('i', b'x' * 32)
+        assert len(b) != 16
+
+        # Read into it. We should get as many *bytes* as we can fit into b
+        # (which is more than the number of elements)
+        n = bufio.readinto1(b)
+        self.assertGreater(n, len(b))
+
+        # Check that old contents of b are preserved
+        bm = memoryview(b).cast('B')
+        self.assertLess(n, len(bm))
+        self.assertEqual(bm[:n], data[:n])
+        self.assertEqual(bm[n:], b'x' * (len(bm[n:])))
+
     def test_readlines(self):
         def bufio():
             rawio = self.MockRawIO((b"abc\n", b"d\n", b"ef"))
@@ -2778,6 +2843,34 @@ class TextIOWrapperTest(unittest.TestCase):
         self.assertFalse(err)
         self.assertEqual("ok", out.decode().strip())
 
+    def test_read_byteslike(self):
+        r = MemviewBytesIO(b'Just some random string\n')
+        t = self.TextIOWrapper(r, 'utf-8')
+
+        # TextIOwrapper will not read the full string, because
+        # we truncate it to a multiple of the native int size
+        # so that we can construct a more complex memoryview.
+        bytes_val =  _to_memoryview(r.getvalue()).tobytes()
+
+        self.assertEqual(t.read(200), bytes_val.decode('utf-8'))
+
+class MemviewBytesIO(io.BytesIO):
+    '''A BytesIO object whose read method returns memoryviews
+       rather than bytes'''
+
+    def read1(self, len_):
+        return _to_memoryview(super().read1(len_))
+
+    def read(self, len_):
+        return _to_memoryview(super().read(len_))
+
+def _to_memoryview(buf):
+    '''Convert bytes-object *buf* to a non-trivial memoryview'''
+
+    arr = array.array('i')
+    idx = len(buf) - len(buf) % arr.itemsize
+    arr.frombytes(buf[:idx])
+    return memoryview(arr)
 
 class CTextIOWrapperTest(TextIOWrapperTest):
     io = io
@@ -3022,6 +3115,8 @@ class MiscIOTest(unittest.TestCase):
                 self.assertRaises(ValueError, f.readall)
             if hasattr(f, "readinto"):
                 self.assertRaises(ValueError, f.readinto, bytearray(1024))
+            if hasattr(f, "readinto1"):
+                self.assertRaises(ValueError, f.readinto1, bytearray(1024))
             self.assertRaises(ValueError, f.readline)
             self.assertRaises(ValueError, f.readlines)
             self.assertRaises(ValueError, f.seek, 0)