#9 MODBUS test code; fixed rtu, modbus, redstone_rtu, and rsio bugs

test/testutils.lua

@@ -41,4 +41,82 @@ function testutils.test_func_nil(name, f, result)
     println("PASS")
 end
 
+-- get something as a string
+---@param result any
+---@return string
+function testutils.stringify(result)
+    return textutils.serialize(result, { allow_repetitions = true, compact = true })
+end
+
+-- pause for 1 second, or the provided seconds
+---@param seconds? number
+function testutils.pause(seconds)
+    seconds = seconds or 1.0
+---@diagnostic disable-next-line: undefined-field
+    os.sleep(seconds)
+end
+
+-- create a new MODBUS tester
+---@param modbus modbus modbus object
+---@param error_flag MODBUS_FCODE MODBUS_FCODE.ERROR_FLAG
+function testutils.modbus_tester(modbus, error_flag)
+    -- test packet
+    ---@type modbus_frame
+    local packet = {
+        txn_id = 0,
+        length = 0,
+        unit_id = 0,
+        func_code = 0,
+        data = {},
+        scada_frame = nil
+    }
+
+    ---@class modbus_tester
+    local public = {}
+
+    -- set the packet function and data for the next test
+    ---@param func MODBUS_FCODE function code
+    ---@param data table
+    function public.pkt_set(func, data)
+        packet.length = #data
+        packet.data = data
+        packet.func_code = func
+    end
+
+    -- check the current packet, expecting an error
+    ---@param excode MODBUS_EXCODE exception code to expect
+    function public.test_error__check_request(excode)
+        local rcode, reply = modbus.check_request(packet)
+        assert(rcode == false, "CHECK_NOT_FAIL")
+        assert(reply.get().func_code == bit.bor(packet.func_code, error_flag), "WRONG_FCODE")
+        assert(reply.get().data[1] == excode, "EXCODE_MISMATCH")
+    end
+
+    -- test the current packet, expecting an error
+    ---@param excode MODBUS_EXCODE exception code to expect
+    function public.test_error__handle_packet(excode)
+        local rcode, reply = modbus.handle_packet(packet)
+        assert(rcode == false, "CHECK_NOT_FAIL")
+        assert(reply.get().func_code == bit.bor(packet.func_code, error_flag), "WRONG_FCODE")
+        assert(reply.get().data[1] == excode, "EXCODE_MISMATCH")
+    end
+
+    -- check the current packet, expecting success
+    ---@param excode MODBUS_EXCODE exception code to expect
+    function public.test_success__check_request(excode)
+        local rcode, reply = modbus.check_request(packet)
+        assert(rcode, "CHECK_NOT_OK")
+        assert(reply.get().data[1] == excode, "EXCODE_MISMATCH")
+    end
+
+    -- test the current packet, expecting success
+    function public.test_success__handle_packet()
+        local rcode, reply = modbus.handle_packet(packet)
+        assert(rcode, "CHECK_NOT_OK")
+        println(testutils.stringify(reply.get().data))
+    end
+
+    return public
+end
+
 return testutils