Lua: Add Gui Demo to lua tests

Change-Id: I4b9af6702d425867c5f1f6904d6b939a1cede8e6
Reviewed-by: hjk <hjk@qt.io>

src/plugins/luatests/CMakeLists.txt

@@ -7,4 +7,5 @@ add_qtc_lua_plugin(luatests
         luatests/tst_aspectcontainer.lua
         luatests/tst_fetch.lua
         luatests/tst_utils.lua
+        luatests/guidemo.lua
 )

src/plugins/luatests/luatests/guidemo.lua

@@ -0,0 +1,23 @@
+-- Copyright (C) 2024 The Qt Company Ltd.
+-- SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+local Utils = require("Utils")
+local Gui = require("Gui")
+
+local function using(tbl)
+    local result = _G
+    for k, v in pairs(tbl) do result[k] = v end
+    return result
+end
+
+local function show()
+    --- "using namespace Gui"
+    local _ENV = using(Gui)
+
+    Widget {
+        size = { 400, 300 },
+        Row { "Hello World!" },
+    }:show()
+end
+
+return show

src/plugins/luatests/luatests/tests.lua

@@ -64,6 +64,19 @@ local function setup()
         text = "Run lua tests",
         onTrigger = function() a.sync(runTests)() end,
     })
+    Action.create("LuaTests.layoutDemo", {
+        text = "Lua Layout Demo",
+        onTrigger = function()
+            local script, err = loadfile(Utils.FilePath.fromUserInput(script_path()):parentDir():resolvePath(
+            "guidemo.lua"):nativePath())
+            if not script then
+                print("Failed to load demo:", err)
+                return
+            end
+
+            script()()
+        end,
+    })
 end
 
 return { setup = setup }