discourse/lib/discourse_js_processor.rb

233 lines
6.9 KiB
Ruby

# frozen_string_literal: true
require "execjs"
require "mini_racer"
class DiscourseJsProcessor
class TranspileError < StandardError
end
# To generate a list of babel plugins used by ember-cli, set
# babel: { debug: true } in ember-cli-build.js, then run `yarn ember build -prod`
DISCOURSE_COMMON_BABEL_PLUGINS = [
["proposal-decorators", { legacy: true }],
"proposal-class-properties",
"proposal-private-methods",
"proposal-class-static-block",
"transform-parameters",
"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).*$/, "").sub(%r{^/}, "")
data = input[:data]
data = transpile(data, root_path, logical_path) if should_transpile?(input[:filename])
# add sourceURL until we can do proper source maps
if !Rails.env.production? && !ember_cli?(input[:filename])
plugin_name = root_path[%r{/plugins/([\w-]+)/assets}, 1]
source_url =
if plugin_name
"plugins/#{plugin_name}/assets/javascripts/#{logical_path}"
else
logical_path
end
data = "eval(#{data.inspect} + \"\\n//# sourceURL=#{source_url}\");\n"
end
{ data: data }
end
def self.transpile(data, root_path, logical_path, theme_id: nil)
transpiler = Transpiler.new(skip_module: skip_module?(data))
transpiler.perform(data, root_path, logical_path, theme_id: theme_id)
end
def self.should_transpile?(filename)
filename ||= ""
# skip ember cli
return false if ember_cli?(filename)
# es6 is always transpiled
return true if filename.end_with?(".es6") || filename.end_with?(".es6.erb")
# For .js check the path...
return false unless filename.end_with?(".js") || filename.end_with?(".js.erb")
relative_path = filename.sub(Rails.root.to_s, "").sub(%r{^/*}, "")
js_root = "app/assets/javascripts"
test_root = "test/javascripts"
return false if relative_path.start_with?("#{js_root}/locales/")
return false if relative_path.start_with?("#{js_root}/plugins/")
if %w[
start-discourse
onpopstate-handler
google-tag-manager
google-universal-analytics-v3
google-universal-analytics-v4
activate-account
auto-redirect
embed-application
app-boot
].any? { |f| relative_path == "#{js_root}/#{f}.js" }
return true
end
return true if plugin_transpile_paths.any? { |prefix| relative_path.start_with?(prefix) }
!!(relative_path =~ %r{^#{js_root}/[^/]+/} || relative_path =~ %r{^#{test_root}/[^/]+/})
end
def self.skip_module?(data)
!!(data.present? && data =~ %r{^// discourse-skip-module$})
end
class Transpiler
JS_PROCESSOR_PATH =
Rails.env.production? ? "tmp/js-processor.js" : "tmp/js-processor/#{Process.pid}.js"
@mutex = Mutex.new
@ctx_init = Mutex.new
@processor_mutex = Mutex.new
def self.mutex
@mutex
end
def self.generate_js_processor
Discourse::Utils.execute_command(
"yarn",
"--silent",
"esbuild",
"--log-level=warning",
"--bundle",
"--external:fs",
"--define:process='{\"env\":{}}'",
"app/assets/javascripts/js-processor.js",
"--outfile=#{JS_PROCESSOR_PATH}",
)
JS_PROCESSOR_PATH
end
def self.create_new_context
# timeout any eval that takes longer than 15 seconds
ctx = MiniRacer::Context.new(timeout: 15_000, 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) })
# Theme template AST transformation plugins
if Rails.env.development? || Rails.env.test?
@processor_mutex.synchronize { generate_js_processor }
end
ctx.eval(File.read(JS_PROCESSOR_PATH), filename: "js-processor.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
# Call a method in the global scope of the v8 context.
# The `fetch_result_call` kwarg provides a workaround for the lack of mini_racer async
# result support. The first call can perform some async operation, and then `fetch_result_call`
# will be called to fetch the result.
def self.v8_call(*args, **kwargs)
fetch_result_call = kwargs.delete(:fetch_result_call)
mutex.synchronize do
result = v8.call(*args, **kwargs)
result = v8.call(fetch_result_call) if fetch_result_call
result
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,
{
skipModule: @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 =~ %r{(.*/#{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(%r{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
def terser(tree, opts)
self.class.v8_call("minify", tree, opts, fetch_result_call: "getMinifyResult")
end
end
end