Add explicit tests for writelines

Includes two failing tests that demonstrate a bug where if the data passed to writelines can't be sent in one shot, the remaining buffer isn't written since there is no registered write handler
python · kumaraditya303 · Apr 13, 2023 · Apr 11, 2023 · Apr 12, 2023 · Apr 12, 2023
commit 273e1e74a9656b3e45cbc67b284457e730b38ea2
@@ -747,6 +747,46 @@ def test_write_sendmsg_no_data(self):
        self.assertFalse(self.sock.sendmsg.called)
        self.assertEqual(list_to_buffer([b'data']), transport._buffer)

+    def test_writelines_sendmsg_full(self):
+        data = memoryview(b'data')
+        self.sock.sendmsg = mock.Mock()
+        self.sock.sendmsg.return_value = len(data)
+
+        transport = self.socket_transport(sendmsg=True)
+        transport.writelines([data])
+        self.assertTrue(self.sock.sendmsg.called)
+        self.assertFalse(self.loop.writers)
+
+    def test_writelines_sendmsg_partial(self):
+        data = memoryview(b'data')
+        self.sock.sendmsg = mock.Mock()
+        self.sock.sendmsg.return_value = 2
+
+        transport = self.socket_transport(sendmsg=True)
+        transport.writelines([data])
+        self.assertTrue(self.sock.sendmsg.called)
+        self.assertTrue(self.loop.writers)
+
+    def test_writelines_send_full(self):
+        data = memoryview(b'data')
+        self.sock.send.return_value = len(data)
+        self.sock.send.fileno.return_value = 7
+
+        transport = self.socket_transport(sendmsg=False)
+        transport.writelines([data])
+        self.assertTrue(self.sock.send.called)
+        self.assertFalse(self.loop.writers)
+
+    def test_writelines_send_partial(self):
+        data = memoryview(b'data')
+        self.sock.send.return_value = 2
+        self.sock.send.fileno.return_value = 7
+
+        transport = self.socket_transport(sendmsg=False)
+        transport.writelines([data])
+        self.assertTrue(self.sock.send.called)
+        self.assertTrue(self.loop.writers)
+
    @unittest.skipUnless(selector_events._HAS_SENDMSG, 'no sendmsg')
    def test_write_sendmsg_full(self):
        data = memoryview(b'data')