Export translations in parallel.

CHANGELOG.md

@@ -45,6 +45,8 @@ Prefix your message with one of the following:
   validator. Remove it from your config file.
 - [Added] A single plugin class can now appear multiple times in the pipeline
   with different configurations, each running as an independent instance.
+- [Changed] Export translations in parallel. To enable parallel mode, your
+  output file definition must include the `:locale` placeholder.
 
 ## v4.2.3 - Mar 29, 2023
 

i18n-js.gemspec

@@ -37,6 +37,7 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) {|f| File.basename(f) }
   spec.require_paths = ["lib"]
 
+  spec.add_dependency "concurrent-ruby", "~> 1.0", ">= 1.3.1"
   spec.add_dependency "glob", ">= 0.4.0"
   spec.add_dependency "i18n"
 

lib/i18n-js.rb

@@ -8,6 +8,7 @@
 require "optparse"
 require "erb"
 require "digest/md5"
+require "concurrent-ruby"
 
 require_relative "i18n-js/schema"
 require_relative "i18n-js/version"
@@ -56,11 +57,19 @@ def self.export_group(group:, plugins:)
     exported_files = []
 
     if output_file_path.include?(":locale")
+      promises = []
+
       filtered_translations.each_key do |locale|
-        locale_file_path = output_file_path.gsub(":locale", locale.to_s)
-        exported_files << write_file(locale_file_path,
-                                     locale => filtered_translations[locale])
+        promises <<
+          Concurrent::Promises.future(
+            output_file_path.gsub(":locale", locale.to_s),
+            locale => filtered_translations[locale]
+          ) do |locale_file_path, translations|
+            write_file(locale_file_path, translations)
+          end
       end
+
+      exported_files = Concurrent::Promises.zip(*promises).value!
     else
       exported_files << write_file(output_file_path, filtered_translations)
     end