require 'execjs' require 'babel/transpiler' module Tilt class Console def initialize(prefix=nil) @prefix = prefix || '' end def log(msg) Rails.logger.info("#{@prefix}#{msg}") end def error(msg) Rails.logger.error("#{@prefix}#{msg}") end end class ES6ModuleTranspilerTemplate < Tilt::Template self.default_mime_type = 'application/javascript' @mutex = Mutex.new @ctx_init = Mutex.new def prepare # intentionally left empty # Tilt requires this method to be defined end def self.create_new_context ctx = V8::Context.new(timeout: 5000) ctx.eval("var self = this; #{File.read(Babel::Transpiler.script_path)}") ctx.eval("module = {}; exports = {};"); ctx.load("#{Rails.root}/lib/es6_module_transpiler/support/es6-module-transpiler.js") ctx end def self.v8 return @ctx if @ctx # ensure we only init one of these @ctx_init.synchronize do return @ctx if @ctx @ctx = create_new_context end @ctx end class JavaScriptError < StandardError attr_accessor :message, :backtrace def initialize(message, backtrace) @message = message @backtrace = backtrace end end def self.protect rval = nil @mutex.synchronize do begin rval = yield # This may seem a bit odd, but we don't want to leak out # objects that require locks on the v8 vm, to get a backtrace # you need a lock, if this happens in the wrong spot you can # deadlock a process rescue V8::Error => e raise JavaScriptError.new(e.message, e.backtrace) end end rval end def whitelisted?(path) @@whitelisted ||= Set.new( ["discourse/models/nav-item", "discourse/models/user-action", "discourse/routes/discourse", "discourse/models/category", "discourse/models/trust-level", "discourse/models/site", "discourse/models/user", "discourse/models/session", "discourse/models/model", "discourse/models/topic", "discourse/models/post", "discourse/views/grouped"] ) @@whitelisted.include?(path) || path =~ /discourse\/mixins/ end def evaluate(scope, locals, &block) return @output if @output klass = self.class klass.protect do klass.v8['console'] = Console.new("BABEL: #{scope.logical_path}: ") @output = klass.v8.eval(generate_source(scope)) end # For backwards compatibility with plugins, for now export the Global format too. # We should eventually have an upgrade system for plugins to use ES6 or some other # resolve based API. if whitelisted?(scope.logical_path) && scope.logical_path =~ /(discourse|admin)\/(controllers|components|views|routes|mixins|models)\/(.*)/ type = Regexp.last_match[2] file_name = Regexp.last_match[3].gsub(/[\-\/]/, '_') class_name = file_name.classify # Rails removes pluralization when calling classify if file_name.end_with?('s') && (!class_name.end_with?('s')) class_name << "s" end require_name = module_name(scope.root_path, scope.logical_path) if require_name !~ /\-test$/ && require_name !~ /^discourse\/plugins\// result = "#{class_name}#{type.classify}" # HAX result = "Controller" if result == "ControllerController" result = "Route" if result == "DiscourseRoute" result = "View" if result == "ViewView" result.gsub!(/Mixin$/, '') result.gsub!(/Model$/, '') if result != "PostMenuView" @output << "\n\nDiscourse.#{result} = require('#{require_name}').default;\n" end end end @output end private def generate_source(scope) js_source = ::JSON.generate(data, quirks_mode: true) js_source = "babel.transform(#{js_source}, {ast: false, whitelist: ['es6.constants', 'es6.properties.shorthand', 'es6.arrowFunctions', 'es6.blockScoping', 'es6.destructuring', 'es6.spread', 'es6.parameters', 'es6.templateLiterals', 'es6.regex.unicode', 'es7.decorators', 'es6.classes']})['code']" "new module.exports.Compiler(#{js_source}, '#{module_name(scope.root_path, scope.logical_path)}', #{compiler_options}).#{compiler_method}()" end def module_name(root_path, logical_path) path = nil root_base = File.basename(Rails.root) # If the resource is a plugin, use the plugin name as a prefix if root_path =~ /(.*\/#{root_base}\/plugins\/[^\/]+)\// plugin_path = "#{Regexp.last_match[1]}/plugin.rb" plugin = Discourse.plugins.find {|p| p.path == plugin_path } path = "discourse/plugins/#{plugin.name}/#{logical_path.sub(/javascripts\//, '')}" if plugin end path ||= logical_path if ES6ModuleTranspiler.transform path = ES6ModuleTranspiler.transform.call(path) end path end def compiler_method type = { amd: 'AMD', cjs: 'CJS', globals: 'Globals' }[ES6ModuleTranspiler.compile_to.to_sym] "to#{type}" end def compiler_options ::JSON.generate(ES6ModuleTranspiler.compiler_options, quirks_mode: true) end end end