From f9b138724c5ef9f3553724abfd77d4aa6790e26f Mon Sep 17 00:00:00 2001
From: Thomas Watson <twatson52@icloud.com>
Date: Sun, 2 Jun 2024 14:52:02 -0500
Subject: [PATCH] AP_Scripting: add serial loopback test script

Tests that data can flow both ways with one end using protocol 28
(Scripting) and the other using the serial device simulation feature.
---
 .../AP_Scripting/tests/serial_loopback.lua    | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 libraries/AP_Scripting/tests/serial_loopback.lua

diff --git a/libraries/AP_Scripting/tests/serial_loopback.lua b/libraries/AP_Scripting/tests/serial_loopback.lua
new file mode 100644
index 0000000000..9893c8f7d8
--- /dev/null
+++ b/libraries/AP_Scripting/tests/serial_loopback.lua
@@ -0,0 +1,36 @@
+local ser_driver = serial:find_serial(0)
+local ser_device = serial:find_simulated_device(28, 0)
+
+if ser_driver == nil or ser_device == nil then
+  error("bad config")
+end
+
+ser_driver:begin(115200) -- baud rate does not matter
+
+function test_driver_to_device()
+  local msg_send = "hello device"
+  local num_sent = 0
+  for ci = 1,#msg_send do
+    num_sent = num_sent + ser_driver:write(msg_send:byte(ci, ci)):toint()
+  end
+  local msg_recv = ser_device:readstring(#msg_send)
+  if msg_send == msg_recv and num_sent == #msg_send then
+    gcs:send_text(6, "driver -> device good")
+  end
+end
+
+function test_device_to_driver()
+  local msg_send = "hello driver"
+  local num_sent = ser_device:writestring(msg_send)
+  local msg_recv = ser_driver:readstring(#msg_send)
+  if msg_send == msg_recv and num_sent == #msg_send then
+    gcs:send_text(6, "device -> driver good")
+  end
+end
+
+function update()
+  test_driver_to_device()
+  test_device_to_driver()
+end
+
+return update()