Add lua exception handling test code

Catch some error situations when mod used without thinking about it

1 files changed, 106 insertions, 0 deletions

diff --git a/games/minimal/mods/errorhandler_test/init.lua b/games/minimal/mods/errorhandler_test/init.lua
new file mode 100644
index 000000000..9d1535c1d
--- /dev/null
+++ b/games/minimal/mods/errorhandler_test/init.lua
@@ -0,0 +1,106 @@
+--
+-- exception handler test module
+--
+--
+-- To avoid this from crashing the module will startup in inactive mode.
+-- to make specific errors happen you need to cause them by following
+-- chat command:
+--
+-- exceptiontest <location> <errortype>
+--
+-- location has to be one of:
+--   * mapgen:          cause in next on_generate call
+--   * entity_step:     spawn a entity and make it do error in on_step
+--   * globalstep:      do error in next globalstep
+--   * immediate:       cause right in chat handler
+--
+-- errortypes defined are:
+--   * segv:            make sigsegv happen
+--   * zerodivision:    cause a division by zero to happen
+--   * exception:       throw an exception
+
+if core.cause_error == nil or
+	type(core.cause_error) ~= "function" then
+	return
+end
+	
+
+core.log("action", "WARNING: loading exception handler test module!")
+
+local exceptiondata = {
+	tocause = "none",
+	mapgen = false,
+	entity_step = false,
+	globalstep = false,
+}
+
+local exception_entity =
+{
+	on_step = function(self, dtime)
+		if exceptiondata.entity_step then
+			core.cause_error(exceptiondata.tocause)
+		end
+	end,
+}
+local exception_entity_name = "errorhandler_test:error_entity"
+
+local function exception_chat_handler(playername, param)
+	local parameters = param:split(" ")
+	
+	if #parameters ~= 2 then
+		core.chat_send_player(playername, "Invalid argument count for exceptiontest")
+	end
+	
+	core.log("error", "Causing error at:" .. parameters[1])
+	
+	if parameters[1] == "mapgen" then
+		exceptiondata.tocause = parameters[2]
+		exceptiondata.mapgen = true
+	elseif parameters[1] == "entity_step" then
+		--spawn entity at player location
+		local player = core.get_player_by_name(playername)
+		
+		if player:is_player() then
+			local pos = player:getpos()
+			
+			core.add_entity(pos, exception_entity_name)
+		end
+		
+		exceptiondata.tocause = parameters[2]
+		exceptiondata.entity_step = true
+		
+	elseif parameters[1] == "globalstep" then
+		exceptiondata.tocause = parameters[2]
+		exceptiondata.globalstep = true
+		
+	elseif parameters[1] == "immediate" then
+		core.cause_error(parameters[2])
+		
+	else
+		core.chat_send_player(playername, "Invalid error location: " .. dump(parameters[1]))
+	end
+end
+
+core.register_chatcommand("exceptiontest",
+	{
+		params      = "<location> <errortype>",
+		description = "cause a given error to happen.\n" ..
+				" location=(mapgen,entity_step,globalstep,immediate)\n" ..
+				" errortype=(segv,zerodivision,exception)",
+		func        = exception_chat_handler,
+		privs       = { server=true }
+	})
+	
+core.register_globalstep(function(dtime)
+	if exceptiondata.globalstep then
+		core.cause_error(exceptiondata.tocause)
+	end
+end)
+
+core.register_on_generated(function(minp, maxp, blockseed)
+	if exceptiondata.mapgen then
+		core.cause_error(exceptiondata.tocause)
+	end
+end)
+
+core.register_entity(exception_entity_name, exception_entity)