discourse/lib/discourse_js_processor.rb

281 lines
9.2 KiB
Ruby

# frozen_string_literal: true
require 'execjs'
require 'mini_racer'
class DiscourseJsProcessor
class TranspileError < StandardError; end
DISCOURSE_COMMON_BABEL_PLUGINS = [
'proposal-optional-chaining',
['proposal-decorators', { legacy: true } ],
'transform-template-literals',
'proposal-class-properties',
'proposal-class-static-block',
'proposal-private-property-in-object',
'proposal-private-methods',
'proposal-numeric-separator',
'proposal-logical-assignment-operators',
'proposal-nullish-coalescing-operator',
'proposal-json-strings',
'proposal-optional-catch-binding',
'transform-parameters',
'proposal-async-generator-functions',
'proposal-object-rest-spread',
'proposal-export-namespace-from',
]
def self.plugin_transpile_paths
@@plugin_transpile_paths ||= Set.new
end
def self.ember_cli?(filename)
filename.include?("/app/assets/javascripts/discourse/dist/")
end
def self.call(input)
root_path = input[:load_path] || ''
logical_path = (input[:filename] || '').sub(root_path, '').gsub(/\.(js|es6).*$/, '').sub(/^\//, '')
data = input[:data]
if should_transpile?(input[:filename])
data = transpile(data, root_path, logical_path)
end
# add sourceURL until we can do proper source maps
if !Rails.env.production? && !ember_cli?(input[:filename])
plugin_name = root_path[/\/plugins\/([\w-]+)\/assets/, 1]
source_url = if plugin_name
"plugins/#{plugin_name}/assets/javascripts/#{logical_path}"
else
logical_path
end
data = "eval(#{data.inspect} + \"\\n//# sourceURL=#{source_url}\");\n"
end
{ data: data }
end
def self.transpile(data, root_path, logical_path, theme_id: nil)
transpiler = Transpiler.new(skip_module: skip_module?(data))
transpiler.perform(data, root_path, logical_path, theme_id: theme_id)
end
def self.should_transpile?(filename)
filename ||= ''
# skip ember cli
return false if ember_cli?(filename)
# es6 is always transpiled
return true if filename.end_with?(".es6") || filename.end_with?(".es6.erb")
# For .js check the path...
return false unless filename.end_with?(".js") || filename.end_with?(".js.erb")
relative_path = filename.sub(Rails.root.to_s, '').sub(/^\/*/, '')
js_root = "app/assets/javascripts"
test_root = "test/javascripts"
return false if relative_path.start_with?("#{js_root}/locales/")
return false if relative_path.start_with?("#{js_root}/plugins/")
return true if %w(
start-discourse
onpopstate-handler
google-tag-manager
google-universal-analytics-v3
google-universal-analytics-v4
activate-account
auto-redirect
embed-application
app-boot
).any? { |f| relative_path == "#{js_root}/#{f}.js" }
return true if plugin_transpile_paths.any? { |prefix| relative_path.start_with?(prefix) }
!!(relative_path =~ /^#{js_root}\/[^\/]+\// ||
relative_path =~ /^#{test_root}\/[^\/]+\//)
end
def self.skip_module?(data)
!!(data.present? && data =~ /^\/\/ discourse-skip-module$/)
end
class Transpiler
@mutex = Mutex.new
@ctx_init = Mutex.new
def self.mutex
@mutex
end
def self.load_file_in_context(ctx, path, wrap_in_module: nil)
contents = File.read("#{Rails.root}/app/assets/javascripts/#{path}")
if wrap_in_module
contents = <<~JS
define(#{wrap_in_module.to_json}, ["exports", "require", "module"], function(exports, require, module){
#{contents}
});
JS
end
ctx.eval(contents, filename: path)
end
def self.create_new_context
# timeout any eval that takes longer than 15 seconds
ctx = MiniRacer::Context.new(timeout: 15000, ensure_gc_after_idle: 2000)
# General shims
ctx.attach("rails.logger.info", proc { |err| Rails.logger.info(err.to_s) })
ctx.attach("rails.logger.warn", proc { |err| Rails.logger.warn(err.to_s) })
ctx.attach("rails.logger.error", proc { |err| Rails.logger.error(err.to_s) })
ctx.eval(<<~JS, filename: "environment-setup.js")
window = {};
console = {
prefix: "[DiscourseJsProcessor] ",
log: function(...args){ rails.logger.info(console.prefix + args.join(" ")); },
warn: function(...args){ rails.logger.warn(console.prefix + args.join(" ")); },
error: function(...args){ rails.logger.error(console.prefix + args.join(" ")); }
};
JS
# define/require support
load_file_in_context(ctx, "mini-loader.js")
# Babel
load_file_in_context(ctx, "node_modules/@babel/standalone/babel.js")
ctx.eval <<~JS
globalThis.rawBabelTransform = function(){
return Babel.transform(...arguments).code;
}
JS
# Template Compiler
load_file_in_context(ctx, "node_modules/ember-source/dist/ember-template-compiler.js")
load_file_in_context(ctx, "node_modules/babel-plugin-ember-template-compilation/src/plugin.js", wrap_in_module: "babel-plugin-ember-template-compilation/index")
load_file_in_context(ctx, "node_modules/babel-plugin-ember-template-compilation/src/expression-parser.js", wrap_in_module: "babel-plugin-ember-template-compilation/expression-parser")
load_file_in_context(ctx, "node_modules/babel-import-util/src/index.js", wrap_in_module: "babel-import-util")
load_file_in_context(ctx, "node_modules/ember-cli-htmlbars/lib/colocated-babel-plugin.js", wrap_in_module: "colocated-babel-plugin")
# Widget HBS compiler
widget_hbs_compiler_source = File.read("#{Rails.root}/lib/javascripts/widget-hbs-compiler.js")
widget_hbs_compiler_source = <<~JS
define("widget-hbs-compiler", ["exports"], function(exports){
#{widget_hbs_compiler_source}
});
JS
widget_hbs_compiler_transpiled = ctx.call("rawBabelTransform", widget_hbs_compiler_source, {
ast: false,
moduleId: 'widget-hbs-compiler',
plugins: DISCOURSE_COMMON_BABEL_PLUGINS
})
ctx.eval(widget_hbs_compiler_transpiled, filename: "widget-hbs-compiler.js")
# Raw HBS compiler
load_file_in_context(ctx, "node_modules/handlebars/dist/handlebars.js", wrap_in_module: "handlebars")
raw_hbs_transpiled = ctx.call(
"rawBabelTransform",
File.read("#{Rails.root}/app/assets/javascripts/discourse-common/addon/lib/raw-handlebars.js"),
{
ast: false,
moduleId: "raw-handlebars",
plugins: [
['transform-modules-amd', { noInterop: true }],
*DISCOURSE_COMMON_BABEL_PLUGINS
]
}
)
ctx.eval(raw_hbs_transpiled, filename: "raw-handlebars.js")
# Theme template AST transformation plugins
load_file_in_context(ctx, "discourse-js-processor.js", wrap_in_module: "discourse-js-processor")
# Make interfaces available via `v8.call`
ctx.eval <<~JS
globalThis.compileRawTemplate = require('discourse-js-processor').compileRawTemplate;
globalThis.transpile = require('discourse-js-processor').transpile;
JS
ctx
end
def self.reset_context
@ctx&.dispose
@ctx = nil
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
def self.v8_call(*args, **kwargs)
mutex.synchronize do
v8.call(*args, **kwargs)
end
rescue MiniRacer::RuntimeError => e
message = e.message
begin
# Workaround for https://github.com/rubyjs/mini_racer/issues/262
possible_encoded_message = message.delete_prefix("Error: ")
decoded = JSON.parse("{\"value\": #{possible_encoded_message}}")["value"]
message = "Error: #{decoded}"
rescue JSON::ParserError
message = e.message
end
transpile_error = TranspileError.new(message)
transpile_error.set_backtrace(e.backtrace)
raise transpile_error
end
def initialize(skip_module: false)
@skip_module = skip_module
end
def perform(source, root_path = nil, logical_path = nil, theme_id: nil)
self.class.v8_call(
"transpile",
source,
{
skip_module: @skip_module,
moduleId: module_name(root_path, logical_path),
filename: logical_path || 'unknown',
themeId: theme_id,
commonPlugins: DISCOURSE_COMMON_BABEL_PLUGINS
}
)
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
# We need to strip the app subdirectory to replicate how ember-cli works.
path || logical_path&.gsub('app/', '')&.gsub('addon/', '')&.gsub('admin/addon', 'admin')
end
def compile_raw_template(source, theme_id: nil)
self.class.v8_call("compileRawTemplate", source, theme_id)
end
end
end