Clean up defer module and split DeferMethod to its own method

modules/defer.lua

@@ -1,74 +1,78 @@
 local _, addon = ...
 
 local queue = {}
-local function iterateQueue()
+local function iterate()
 	for _, info in next, queue do
 		if info.callback then
-			info.callback(unpack(info.args))
+			local successful, ret = pcall(info.callback, unpack(info.args))
+			if not successful then
+				error(ret)
+			end
 		elseif info.object then
-			info.object[info.method](unpack(info.args))
+			local successful, ret = pcall(info.object[info.method], info.object, unpack(info.args))
+			if not successful then
+				error(ret)
+			end
 		end
 	end
 
 	table.wipe(queue)
-	return true -- unregister itself
+	return true -- unregister event
 end
 
-local function deferFunction(callback, ...)
+local function defer(info)
+	table.insert(queue, info)
+
+	if not addon:IsEventRegistered('PLAYER_REGEN_ENABLED', iterate) then
+		addon:RegisterEvent('PLAYER_REGEN_ENABLED', iterate)
+	end
+end
+
+
+--[[ namespace:Defer(_callback_[, _..._])
+Defers a function `callback` (with optional arguments) until after combat ends.  
+Callback can be the global name of a function.  
+Triggers immediately if player is not in combat.
+--]]
+function addon:Defer(callback, ...)
+	if type(callback) == 'string' then
+		callback = _G[callback]
+	end
+
+	addon:ArgCheck(callback, 1, 'function')
+
 	if InCombatLockdown() then
-		table.insert(queue, {
+		defer({
 			callback = callback,
 			args = {...},
 		})
-
-		if not addon:IsEventRegistered('PLAYER_REGEN_ENABLED', iterateQueue) then
-			addon:RegisterEvent('PLAYER_REGEN_ENABLED', iterateQueue)
-		end
 	else
-		callback(...)
+		local successful, ret = pcall(callback, ...)
+		if not successful then
+			error(ret)
+		end
 	end
 end
 
-local function deferGlobalFunction(func, ...)
-	deferFunction(_G[func], ...)
-end
+--[[ namespace:DeferMethod(_object_, _method_[, _..._])
+Defers a `method` on `object` (with optional arguments) until after combat ends.  
+Triggers immediately if player is not in combat.
+--]]
+function addon:DeferMethod(object, method, ...)
+	addon:ArgCheck(object, 1, 'table')
+	addon:ArgCheck(method, 2, 'string')
+	addon:ArgCheck(object[method], 2, 'function')
 
-local function deferMethod(object, method, ...)
 	if InCombatLockdown() then
-		table.insert(queue, {
+		defer({
 			object = object,
 			method = method,
 			args = {...},
 		})
-
-		if not addon:IsEventRegistered('PLAYER_REGEN_ENABLED', iterateQueue) then
-			addon:RegisterEvent('PLAYER_REGEN_ENABLED', iterateQueue)
-		end
 	else
-		object[method](...)
-	end
-end
-
---[[ namespace:Defer(_callback_[, _..._])
-Defers a function `callback` (with optional arguments) until after combat ends.  
-Immediately triggers if player is not in combat.
---]]
---[[ namespace:Defer(_object_, _method_[, _..._])
-Defers a method `method` on `object` (with optional arguments) until after combat ends.  
-Immediately triggers if player is not in combat.
---]]
-function addon:Defer(...)
-	if type(select(1, ...)) == 'table' then
-		assert(type(select(2, ...)) == 'string', 'arg2 must be the name of a method')
-		assert(type(select(1, ...)[select(2, ...)]) == 'function', 'arg2 must be the name of a method')
-		deferMethod(...)
-	elseif type(select(1, ...)) == 'function' then
-		assert(type(select(1, ...)) == 'function', 'arg1 must be a function')
-		deferFunction(...)
-	elseif type(select(1, ...)) == 'string' and type(_G[select(1, ...)]) == 'function' then
-		assert(type(_G[select(1, ...)]) == 'function', 'arg1 must be a function')
-		deferGlobalFunction(...)
-	else
-		error('Invalid arguments passed to Defer')
+		local successful, ret = pcall(object[method], object, ...)
+		if not successful then
+			error(ret)
+		end
 	end
 end