Add workflow that runs simple test with the engine present

mods/default/init.lua

@@ -77,3 +77,19 @@ dofile(default_path.."/crafting.lua")
 dofile(default_path.."/mapgen.lua")
 dofile(default_path.."/aliases.lua")
 dofile(default_path.."/legacy.lua")
+
+-- Smoke test that is run via ./util/test/run.sh
+if minetest.settings:get_bool("minetest_game_smoke_test") then
+	minetest.after(0, function()
+		minetest.emerge_area(vector.new(0, 0, 0), vector.new(32, 32, 32))
+		local pos = vector.new(9, 9, 9)
+		local function check()
+			if minetest.get_node(pos).name ~= "ignore" then
+				minetest.request_shutdown()
+				return
+			end
+			minetest.after(0, check)
+		end
+		check()
+	end)
+end