Add more testing for WriteRegisters.

examples/client_async_calls.py

@@ -137,6 +137,11 @@ async def async_handle_holding_registers(client):
     assert not rr.isError()  # test that call was OK
     assert rr.registers == [10] * 8
 
+    await client.write_registers(1, [10], slave=SLAVE)
+    rr = await client.read_holding_registers(1, 1, slave=SLAVE)
+    assert not rr.isError()  # test that call was OK
+    assert rr.registers == [10]
+
     _logger.info("### write read holding registers")
     arguments = {
         "read_address": 1,

pymodbus/client/mixin.py

@@ -322,11 +322,11 @@ def write_coils(
         )
 
     def write_registers(
-        self, address: int, values: list[int] | int, slave: int = 1, skip_encode: bool = False) -> T:
+        self, address: int, values: list[int], slave: int = 1, skip_encode: bool = False) -> T:
         """Write registers (code 0x10).
 
         :param address: Start address to write to
-        :param values: List of values to write, or a single value to write
+        :param values: List of values to write
         :param slave: (optional) Modbus slave ID
         :param skip_encode: (optional) do not encode values
         :raises ModbusException:

test/sub_function_codes/test_register_write_messages.py

@@ -122,6 +122,10 @@ async def test_write_multiple_register_request(self):
         result = await request.execute(context)
         assert result.function_code == request.function_code
 
+        request = WriteMultipleRegistersRequest(0x00, [0x00])
+        result = await request.execute(context)
+        assert result.function_code == request.function_code
+
         # -----------------------------------------------------------------------#
         # Mask Write Register Request
         # -----------------------------------------------------------------------#