Send DeepL translation requests in multiple batches

config/locales/en.yml

@@ -96,6 +96,8 @@ en:
           Setup DeepL Pro API key via DEEPL_AUTH_KEY environment variable or translation.deepl_api_key
           in config/i18n-tasks.yml. Get the key at https://www.deepl.com/pro.
         no_results: DeepL returned no results.
+        specific_target_missing: You must supply a specific variant for the given target language
+          e.g. en-us instead of en.
     google_translate:
       errors:
         no_api_key: >-

config/locales/ru.yml

@@ -94,6 +94,8 @@ ru:
           Задайте ключ API DeepL через переменную окружения DEEPL_AUTH_KEY или translation.deepl_api_key
           Получите ключ через https://www.deepl.com/pro.
         no_results: DeepL не дал результатов.
+        specific_target_missing: You must supply a specific variant for the given target language
+          e.g. en-us instead of en.
     google_translate:
       errors:
         no_api_key: >-

lib/i18n/tasks/translators/deepl_translator.rb

@@ -4,6 +4,11 @@
 
 module I18n::Tasks::Translators
   class DeeplTranslator < BaseTranslator
+    # max allowed texts per request
+    BATCH_SIZE = 50
+    # those languages must be specified with their sub-kind e.g en-us
+    SPECIFIC_TARGETS= ['en', 'pt'].freeze
+
     def initialize(*)
       begin
         require 'deepl'
@@ -17,12 +22,16 @@ def initialize(*)
     protected
 
     def translate_values(list, from:, to:, **options)
-      result = DeepL.translate(list, to_deepl_compatible_locale(from), to_deepl_compatible_locale(to), options)
-      if result.is_a?(DeepL::Resources::Text)
-        [result.text]
-      else
-        result.map(&:text)
+      results = []
+      list.each_slice(BATCH_SIZE) do |parts|
+        res = DeepL.translate(parts, to_deepl_source_locale(from), to_deepl_target_locale(to), options)
+        if res.is_a?(DeepL::Resources::Text)
+          results << res.text
+        else
+          results += res.map(&:text)
+        end
       end
+      results
     end
 
     def options_for_translate_values(**options)
@@ -60,11 +69,23 @@ def no_results_error_message
 
     private
 
-    # Convert 'es-ES' to 'ES'
-    def to_deepl_compatible_locale(locale)
+    # Convert 'es-ES' to 'ES', en-us to EN
+    def to_deepl_source_locale(locale)
       locale.to_s.split('-', 2).first.upcase
     end
 
+    # Convert 'es-ES' to 'ES' but warn about locales requiring a specific variant
+    def to_deepl_target_locale(locale)
+      loc, sub = locale.to_s.split('-')
+      if SPECIFIC_TARGETS.include?(loc)
+        # Must see how the deepl api evolves, so this could be an error in the future
+        @i18n_tasks.warn_deprecated I18n.t('i18n_tasks.deepl_translate.errors.specific_target_missing') unless sub
+        locale.to_s.upcase
+      else
+        loc.upcase
+      end
+    end
+
     def configure_api_key!
       api_key = @i18n_tasks.translation_config[:deepl_api_key]
       host = @i18n_tasks.translation_config[:deepl_host]

spec/deepl_translate_spec.rb

@@ -6,12 +6,14 @@
 
 RSpec.describe 'DeepL Translation' do
   nil_value_test = ['nil-value-key', nil, nil]
-  text_test      = ['key', "Hello, %{user} O'Neill! How are you?", "Hola, %{user} ¡O'Neill! Como estas?"]
-  html_test      = ['html-key.html', "Hello, <b>%{user} big O'neill</b> ❤︎", "Hola, <b>%{user} gran O'neill</b> ❤︎"]
+  text_test      = ['key', "Hello, %{user} O'Neill! How are you?", "¡Hola, %{user} O'Neill! ¿Cómo estás?"]
   html_test_plrl = ['html-key.html.one', '<span>Hello %{count}</span>', '<span>Hola %{count}</span>']
   array_test     = ['array-key', ['Hello.', nil, '', 'Goodbye.'], ['Hola.', nil, '', 'Adiós.']]
   fixnum_test    = ['numeric-key', 1, 1]
   ref_key_test   = ['ref-key', :reference, :reference]
+  # this test fails atm due to moving of the bold tag =>  "Hola, <b>%{user} </b> gran O'neill ❤︎ "
+  # it could be a bug, but the api also allows to ignore certain tags and there is the new html-markup version which could be used to
+  html_test      = ['html-key.html', "Hello, <b>%{user} big O'neill</b> ❤︎", "Hola, <b>%{user} gran O'neill</b> ❤︎ "]
 
   describe 'real world test' do
     delegate :i18n_task, :in_test_app_dir, :run_cmd, to: :TestCodebase
@@ -53,13 +55,13 @@
 
           run_cmd 'translate-missing', '--backend=deepl'
           expect(task.t('common.hello', 'es')).to eq(text_test[2])
-          expect(task.t('common.hello_html', 'es')).to eq(html_test[2])
           expect(task.t('common.hello_plural_html.one', 'es')).to eq(html_test_plrl[2])
           expect(task.t('common.array_key', 'es')).to eq(array_test[2])
           expect(task.t('common.nil-value-key', 'es')).to eq(nil_value_test[2])
           expect(task.t('common.fixnum-key', 'es')).to eq(fixnum_test[2])
           expect(task.t('common.ref-key', 'es')).to eq(ref_key_test[2])
           expect(task.t('common.a', 'es')).to eq('λ')
+          expect(task.t('common.hello_html', 'es')).to eq(html_test[2])
         end
       end
     end