UniversalSynSaveInstance/Tests/NilInstanceErrorFinder.luau

local ClassList
local GlobalSettings, GlobalBasicSettings = settings(), UserSettings()
local service = setmetatable({}, {
	__index = function(Self, Name)
		local Service = game:GetService(Name) or GlobalSettings:GetService(Name) or GlobalBasicSettings:GetService(Name)
		Self[Name] = Service
		return Service
	end,
})
service.HttpService.HttpEnabled = true
local function ArrayToDictionary(Table, HybridMode)
	local tmp = table.create(#Table)

	if HybridMode == "adjust" then
		for Some1, Some2 in Table do
			if type(Some1) == "number" then
				tmp[Some2] = true
			elseif type(Some2) == "table" then
				tmp[Some1] = ArrayToDictionary(Some2, "adjust") -- Some1 is Class, Some2 is Name
			else
				tmp[Some1] = Some2
			end
		end
	else
		for _, Key in Table do
			tmp[Key] = true
		end
	end

	return tmp
end

local function Find(String, Pattern)
	return string.find(String, Pattern, nil, true)
end

do
	-- TODO: More @ https://github.com/Dekkonot/rbx-instance-serializer/blob/23f772f6f78af879a21faa9fea3e6c4f93d1cdee/src/API.lua#L19

	local function FetchAPI()
		local API_Dump_Url =
			"https://raw.githubusercontent.com/MaximumADHD/Roblox-Client-Tracker/roblox/Mini-API-Dump.json"
		local API_Dump = service.HttpService:GetAsync(API_Dump_Url, true)
		local API_Classes = service.HttpService:JSONDecode(API_Dump).Classes

		local classList = {}

		for _index_0 = 1, #API_Classes do
			local API_Class = API_Classes[_index_0]
			local ClassMembers = API_Class.Members

			local Class = {}

			local ClassName = API_Class.Name

			local ClassTags = API_Class.Tags

			if ClassTags then
				ClassTags = ArrayToDictionary(ClassTags)
			end

			-- ClassInfo.Name = ClassName
			Class.Tags = ClassTags -- or {}
			Class.Superclass = API_Class.Superclass

			local ClassProperties = {}

			for _index_1 = 1, #ClassMembers do
				local Member = ClassMembers[_index_1]
				if Member.MemberType == "Property" then
					local PropertyName = Member.Name

					-- ? We avoid this as some Instances like services may have this property locked and thus make file unable to open and it's not even used by Roblox anyways as Parent-Child relationship is done by embedding/nesting

					local Serialization = Member.Serialization

					if Serialization.CanLoad then
						local Ignored = false
						if not (Ignored and Ignored[PropertyName]) then
							local Allowed = true

							local MemberTags = Member.Tags

							local Special

							if MemberTags then
								MemberTags = ArrayToDictionary(MemberTags)

								Special = MemberTags.NotScriptable

								if MemberTags.Deprecated then
									Allowed = nil
								end
							end
							if Allowed then
								local ValueType = Member.ValueType

								local Property = {
									Name = PropertyName,
									Category = ValueType.Category,
									Default = Member.Default,
									-- Tags = MemberTags,
									ValueType = ValueType.Name,
								}

								if Special then
									Property.Special = true
								end

								ClassProperties[PropertyName] = Property
							end
						end
					end
				end
			end

			Class.Properties = ClassProperties

			classList[ClassName] = Class
		end

		-- classList.Instance.Properties.Parent = nil -- ? Not sure if this is a better option than filtering throguh properties to remove this

		return classList
	end

	local ok, result = pcall(FetchAPI)
	if ok then
		ClassList = result
	else
		warn(result)
		return
	end
end
local F = Instance.new("Folder")
for Class in ClassList do
	local o, r = pcall(Instance.new, Class)
	local x = r
	if not o then
		r = game:FindFirstChild(Class, true)
		if not r then
			r = game:FindFirstChildWhichIsA(Class, true)
		end
	end
	if r then
		o, r = pcall(function(_, _2)
			_.Parent = _2
		end, r, F)
		if not o then
			if Find(r, "locked") or Find(r, "Cannot change") or Find(r, "Invalid parent for Service") then
				continue
			end
			warn(Class, r)
		end
	elseif not (Find(x, "Unable to create an Instance") or Find(x, "The current thread cannot create")) then
		print(Class, x)
	end
end