Roblox elevated/internal plugin demoter

ElevatedPluginDemoter.lua

--[[
	ELEVATED PLUGIN DEMOTER
	"One-click" script to demote elevated (usually internal) plugins by removing or
	replacing their elevated API calls.
	
	NOTE:
	I've only tested this on the "Developer" Storybook plugin (the irony). It will probably
	need some modification for other internal plugins, like the Roact Inspector.
	
	STEPS TO USE:
	1. Find the plugin .rbxm file in Studio's BuiltInPlugins folder. Windows with Mod Manager:
	%LOCALAPPDATA%\Roblox Studio\BuiltInPlugins
	
	2. Drop into a Studio place (empy baseplate, doesn't matter) and select the top-level folder.
	
	3. Copy this script into the command bar and run! Your plugin has now been demoted and you can
	save it as a local plugin to use.
	
	NOTE FOR THE STORYBOOK PLUGIN:
	There is a restriction which prevents plugins from requiring normal modules. You should use the
	Mod Manager to enable the "FFlagEnableLoadModule" flag so that the plugin can use debug.loadmodule
	to bypass this restriction.
	
	This script is mostly a fork of the "DeveloperFramework" (ironic, I know) Embed module, but with
	things added on top for our needs.
	
	Happy developing!
]]

local CONFIG = {
	FallbackFlagValue = false,
	SpoofInternal = true, -- You're gonna wanna leave this on for most plugins to run
}

local root = game:GetService("Selection"):Get()[1]

if (root == nil) then
	warn("You must select the plugin before running this script.")
end

local pluginName = root.Name

local function rewriteMethodCall(name: string, value: any)
	return string.format('select(2, "%s", %s)', name, tostring(value))
end

local function tryCall(fn: () -> any, default: any)
	local ok, result = pcall(function()
		return fn()
	end)
	if ok then
		return result
	else
		return default
	end
end

local function getFlag(flagName: string)
	return tryCall(function()
		return game:GetFastFlag(flagName)
	end, CONFIG.FallbackFlagValue)
end

local function getFeature(featureName: string)
	return tryCall(function()
		return game:GetEngineFeature(featureName)
	end, featureName)
end

local function getString(stringName: string)
	return tryCall(function()
		return game:GetFastString(stringName)
	end, stringName)
end

local function getInt(intName: string)
	return tryCall(function()
		return game:GetFastInt(intName)
	end, intName)
end

local function getFVariable(settingName: string)
	return tryCall(function()
		return settings():GetFVariable(settingName)
	end, CONFIG.FallbackFlagValue)
end

local function rewriteFlag(flagName: string)
	return rewriteMethodCall(flagName, getFlag(flagName))
end

local function rewriteEngineFeature(featureName: string)
	return rewriteMethodCall(featureName, getFeature(featureName))
end
local function rewriteString(stringName: string)
	return rewriteMethodCall(stringName, getString(stringName))
end
local function rewriteInt(intName: string)
	return rewriteMethodCall(intName, getInt(intName))
end
local function rewriteSetting(settingName: string)
	return rewriteMethodCall(settingName, getFVariable(settingName))
end

local function rewriteFlagsForScript(script: ModuleScript)
	-- These API calls are roblox-security only, so cannot be used in a normal plugin
	local src = script.Source
	:gsub([[game:DefineFastFlag%(%s*"([^"]+)"[^)]*%)]], rewriteFlag)
	:gsub([[game:DefineFastString%(%s*"([^"]+)"[^)]*%)]], rewriteString)
	:gsub([[game:GetEngineFeature%(%s*"([^"]+)"[^)]*%)]], rewriteEngineFeature)
	:gsub([[game:GetFastFlag%(%s*"([^"]+)"[^)]*%)]], rewriteFlag)
	:gsub([[game:GetFastString%(%s*"([^"]+)"[^)]*%)]], rewriteString)
	:gsub([[game:GetFastInt%(%s*"([^"]+)"[^)]*%)]], rewriteInt)
	:gsub([[settings%(%):GetFFlag%(%s*"([^"]+)"%)]], rewriteFlag)
	:gsub([[settings%(%):GetFVariable%(%s*"([^"]+)"%)]], rewriteSetting)
	:gsub([[settings%(%):GetFVariable%(%s*"([^"]+)"%)]], rewriteSetting)
	:gsub([[game:GetService%("StudioService"%):HasInternalPermission%(%)]], tostring(CONFIG.SpoofInternal))
	:gsub([[game:GetService%("StudioService"%)]], [[({StudioLocaleId = "en-us", GetPropertyChangedSignal = function() return {Connect = function() return {Disconnect = function() end} end} end, HasInternalPermission = function() return true end, FindFirstChild = function(n) game:GetService("StudioService"):FindFirstChild(n) end})]])
	:gsub([[game:GetService%("ABTestService"%)]], [[({GetVariant = function() return "Control" end})]])

	-- The "Flags" util module produces some annoying warnings, remove them.
	:gsub([[warn%("An error occurred defining the fast flag: " .. flagName%)]], "")
	:gsub([[warn%(err%)]], "")

	-- Places a bindable event under StudioService, doesn't work with this bypass. Put it somewhere else.
	:gsub([[BindableEventBridge%.new%(Services.getStudioService%(%)%)]], [[BindableEventBridge.new(game:GetService("CoreGui"))]])

	-- Used by the Roact Inspector to get plugin GUIs, but we probably won't need this - keeping it will error.
	:gsub([[Services%.getRobloxPluginGuiService%(%):WaitForChild%(pluginName, 10%)]], "nil")

	-- There's not really any good way to replace the dialog setup, so just disable it entirely
	:gsub([[local Dialog = createPluginWidget%("Dialog", function%(props%)+.+%send%)]], "local Dialog = function() end")
	:gsub([[Typecheck%.wrap%(Dialog, script%)]], "")

	-- Prevent elevated plugins from setting PluginAction.Enabled
	:gsub([[action%.Enabled = %a+]], "")
	:gsub([[action%.DefaultShortcut = definition%.defaultShortcut]], "")

	-- PLUGIN SPECIFIC FIXES
	if (pluginName == "DeveloperStorybook") then
		src = src
		:gsub([[local STORYBOOK_SOURCES]], [[local STORYBOOK_SOURCES = {"ReplicatedStorage","ReplicatedFirst","ServerScriptService","StarterGui","StarterPlayer"} local STORYBOOK_SOURCES_OLD]])
	elseif (pluginName == "DeveloperInspector") then
		src = src
		:gsub([[toggleProfile.Enabled = %w+]], "")
	end
	
	local success = pcall(function()
		script.Source = src
	end)
	
	if not success then
		warn("Failed to write source of module:", script:GetFullName())
	end
end

local function visitInstance(obj: Instance)
	if (not (obj:IsA("ModuleScript") or obj:IsA("BaseScript"))) then return end
	if (obj == script) then return end
	if (obj.Name == "runTests") then
		(obj :: Script).Disabled = true
		return
	end

	rewriteFlagsForScript(obj :: ModuleScript)
end

local function run()
	local instances = root:GetDescendants()
	local instanceCount = #instances

	print(("Demoting plugin: %s\nInstances to scan:%s"):format(pluginName, instanceCount))

	for _, obj in ipairs(instances) do
		visitInstance(obj)
	end

	print(("Demoted plugin %s"):format(pluginName))
end

run()