discourse/lib/discourse_js_processor.rb

228 lines
7.1 KiB
Ruby

# frozen_string_literal: true
require 'execjs'
require 'mini_racer'
class DiscourseJsProcessor
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).*$/, '').sub(/^\//, '')
data = input[:data]
if should_transpile?(input[:filename])
data = transpile(data, root_path, logical_path)
end
# add sourceURL until we can do proper source maps
if !Rails.env.production? && !ember_cli?(input[:filename])
plugin_name = root_path[/\/plugins\/([\w-]+)\/assets/, 1]
source_url = if plugin_name
"plugins/#{plugin_name}/assets/javascripts/#{logical_path}"
else
logical_path
end
data = "eval(#{data.inspect} + \"\\n//# sourceURL=#{source_url}\");\n"
end
{ data: data }
end
def self.transpile(data, root_path, logical_path)
transpiler = Transpiler.new(skip_module: skip_module?(data))
transpiler.perform(data, root_path, logical_path)
end
def self.should_transpile?(filename)
filename ||= ''
# skip ember cli
return false if ember_cli?(filename)
# es6 is always transpiled
return true if filename.end_with?(".es6") || filename.end_with?(".es6.erb")
# For .js check the path...
return false unless filename.end_with?(".js") || filename.end_with?(".js.erb")
relative_path = filename.sub(Rails.root.to_s, '').sub(/^\/*/, '')
js_root = "app/assets/javascripts"
test_root = "test/javascripts"
return false if relative_path.start_with?("#{js_root}/locales/")
return false if relative_path.start_with?("#{js_root}/plugins/")
return true if %w(
start-discourse
onpopstate-handler
google-tag-manager
google-universal-analytics-v3
google-universal-analytics-v4
activate-account
auto-redirect
embed-application
app-boot
).any? { |f| relative_path == "#{js_root}/#{f}.js" }
return true if plugin_transpile_paths.any? { |prefix| relative_path.start_with?(prefix) }
!!(relative_path =~ /^#{js_root}\/[^\/]+\// ||
relative_path =~ /^#{test_root}\/[^\/]+\//)
end
def self.skip_module?(data)
!!(data.present? && data =~ /^\/\/ discourse-skip-module$/)
end
class Transpiler
@mutex = Mutex.new
@ctx_init = Mutex.new
def self.mutex
@mutex
end
def self.create_new_context
# timeout any eval that takes longer than 15 seconds
ctx = MiniRacer::Context.new(timeout: 15000, ensure_gc_after_idle: 2000)
ctx.eval("#{File.read("#{Rails.root}/app/assets/javascripts/node_modules/@babel/standalone/babel.js")}")
ctx.eval(File.read(Ember::Source.bundled_path_for('ember-template-compiler.js')))
ctx.eval("module = {}; exports = {};")
ctx.eval("const DISCOURSE_COMMON_BABEL_PLUGINS = #{DISCOURSE_COMMON_BABEL_PLUGINS.to_json};")
ctx.attach("rails.logger.info", proc { |err| Rails.logger.info(err.to_s) })
ctx.attach("rails.logger.error", proc { |err| Rails.logger.error(err.to_s) })
ctx.eval <<JS
console = {
prefix: "",
log: function(msg){ rails.logger.info(console.prefix + msg); },
error: function(msg){ rails.logger.error(console.prefix + msg); }
}
JS
source = File.read("#{Rails.root}/lib/javascripts/widget-hbs-compiler.js")
js_source = ::JSON.generate(source, quirks_mode: true)
js = ctx.eval("Babel.transform(#{js_source}, { ast: false, plugins: ['transform-arrow-functions', 'transform-block-scoped-functions', 'transform-block-scoping', 'transform-computed-properties', 'transform-destructuring', 'transform-duplicate-keys', 'transform-for-of', 'transform-function-name', 'transform-literals', 'transform-object-super', 'transform-parameters', 'transform-shorthand-properties', 'transform-spread', 'transform-sticky-regex', 'transform-template-literals', 'transform-typeof-symbol', 'transform-unicode-regex', 'proposal-object-rest-spread', 'proposal-optional-chaining'] }).code")
ctx.eval(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 initialize(skip_module: false)
@skip_module = skip_module
end
def perform(source, root_path = nil, logical_path = nil)
klass = self.class
klass.mutex.synchronize do
klass.v8.eval("console.prefix = 'BABEL: babel-eval: ';")
transpiled = babel_source(
source,
module_name: module_name(root_path, logical_path),
filename: logical_path
)
@output = klass.v8.eval(transpiled)
end
end
def babel_source(source, opts = nil)
opts ||= {}
js_source = ::JSON.generate(source, quirks_mode: true)
if opts[:module_name] && !@skip_module
filename = opts[:filename] || 'unknown'
<<~JS
Babel.transform(
#{js_source},
{
moduleId: '#{opts[:module_name]}',
filename: '#{filename}',
ast: false,
plugins: [
exports.WidgetHbsCompiler,
['transform-modules-amd', {noInterop: true}],
...DISCOURSE_COMMON_BABEL_PLUGINS
]
}
).code
JS
else
<<~JS
Babel.transform(
#{js_source},
{
ast: false,
plugins: [
exports.WidgetHbsCompiler,
...DISCOURSE_COMMON_BABEL_PLUGINS
]
}
).code
JS
end
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
end
end