Add error for old syntax, which passes constructor arguments to new()

Author: vaisest

spec/System/TestCommon_spec.lua

@@ -17,5 +17,19 @@ describe("Common", function()
 			common.classes.ConstructorTestParent = nil
 			common.classes.ConstructorTestProblemChild = nil
 		end)
+		it("produces an error if additional arguments are passed", function()
+			local StupidClass = newClass("NewAbuse")
+			function StupidClass:NewAbuse(someParam)
+			end
+
+			common.classes.NewAbuse = StupidClass
+
+			assert.has_no.errors(function()
+				local newObj = new("NewAbuse"):NewAbuse("fish")
+			end)
+			assert.has_error(function()
+				local newObj = new("NewAbuse", "look I'm using the old syntax")
+			end)
+		end)
 	end)
 end)

src/Modules/Common.lua

@@ -119,8 +119,15 @@ end
 
 ---@generic T
 ---@param className `T`
+---@param extraArg nil Never pass extra parameters. Defined purely to guard against old syntax.
 ---@return T
-function new(className)
+function new(className, extraArg)
+	if extraArg then
+		local line = s_format(
+			"Extra argument passed to new() during creation of class %s. Extra arguments are not allowed.\nAre you perhaps trying to pass constructor arguments here?",
+			className)
+		error(line)
+	end
 	local class = getClass(className)
 	local object = setmetatable({ }, class)
 	object.Object = object