Translators: Catches translation errors

CHANGES.md

@@ -24,6 +24,7 @@ to use the Prism Scanner without Rails support.
 - Loads environment variables via `dotenv` if available. [#395](https://github.com/glebm/i18n-tasks/issues/395)
 - Adds CLI command `check_prism` to try the new parser out and see the differences in key detection.
 - The Prism-based scanner supports candidate_keys for Rails translations, allowing relative translations in controllers to match either the key scoped to controller and action or only to the controller.
+- Translation services now catch errors and save partial results [#642](https://github.com/glebm/i18n-tasks/issues/642)
 
 ## v1.0.15
 

lib/i18n/tasks/translators/base_translator.rb

@@ -21,7 +21,22 @@ def translate_forest(forest, from)
 
           @progress_bar = ProgressBar.create(total: pairs.flatten.size, format: "%a <%B> %e %c/%C (%p%%)")
 
-          translated = translate_pairs(pairs, to: root.key, from: from)
+          begin
+            translated = translate_pairs(pairs, to: root.key, from: from)
+          rescue => e
+            warn "Translation for locale #{root.key} failed: #{e.message}"
+            # If translate_pairs raised, try to salvage any partial translations
+            # by attempting to translate each slice individually and collecting successes.
+            translated = []
+            pairs.group_by { |k_v| @i18n_tasks.html_key? k_v[0], from }.each do |_is_html, list_slice|
+              translated.concat(fetch_translations(list_slice, to: root.key, from: from))
+            rescue => e2
+              warn "Partial translation failed for locale #{root.key}: #{e2.message} - leaving keys untranslated"
+              # leave the original list_slice untranslated
+              translated.concat(list_slice)
+            end
+          end
+
           result.merge! Data::Tree::Siblings.from_flat_pairs(translated)
         end
       end
@@ -40,6 +55,10 @@ def translate_pairs(list, opts)
         list -= reference_key_vals
         result = list.group_by { |k_v| @i18n_tasks.html_key? k_v[0], opts[:from] }.map do |is_html, list_slice|
           fetch_translations(list_slice, opts.merge(is_html ? options_for_html : options_for_plain))
+        rescue => e
+          warn "Translation slice failed: #{e.message} - leaving slice untranslated"
+          # Return the original untranslated slice so already completed translations are preserved
+          list_slice
         end.reduce(:+) || []
         result.concat(reference_key_vals)
         result.sort! { |a, b| key_pos[a[0]] <=> key_pos[b[0]] }
@@ -128,10 +147,10 @@ def replace_interpolations(value)
       # @param [String] translated
       # @return [String] 'hello, <round-trippable string>' => 'hello, %{name}'
       def restore_interpolations(untranslated, translated)
-        return translated if untranslated !~ INTERPOLATION_KEY_RE
+        return translated if !INTERPOLATION_KEY_RE.match?(untranslated)
 
         values = untranslated.scan(INTERPOLATION_KEY_RE)
-        translated.gsub(/#{Regexp.escape(UNTRANSLATABLE_STRING)}\d+/i) do |m|
+        translated.gsub(/#{Regexp.escape(UNTRANSLATABLE_STRING)}\d+/io) do |m|
           values[m[UNTRANSLATABLE_STRING.length..].to_i]
         end
       rescue => e

spec/translators/partial_failures_spec.rb

@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+RSpec.describe I18n::Tasks::Translators::BaseTranslator do
+  let(:task) { I18n::Tasks::BaseTask.new }
+
+  # Create a fake translator that raises for html slices
+  let(:translator_class) do
+    Class.new(described_class) do
+      def translate_values(list, **options)
+        if options[:html]
+          raise StandardError, "html translation failure"
+        end
+
+        # return translated values simply by appending `-es` for testing
+        list.map { |v| "#{v}-es" }
+      end
+
+      def options_for_translate_values(from:, to:, **options)
+        options.merge(from: from, to: to)
+      end
+
+      def options_for_html
+        {html: true}
+      end
+
+      def options_for_plain
+        {html: false}
+      end
+
+      def no_results_error_message
+        "no results"
+      end
+    end
+  end
+
+  it "preserves successful translations when a subsequent slice fails" do
+    translator = translator_class.new(task)
+
+    list = [
+      ["common.plain", "Hello"],
+      ["common.html.html", "<b>Hi</b>"]
+    ]
+
+    result = translator.send(:translate_pairs, list, from: "en", to: "es")
+
+    # Find translated plain key
+    plain = result.assoc("common.plain")
+    expect(plain).not_to be_nil
+    expect(plain.last).to eq("Hello-es")
+
+    # HTML slice should have been left untranslated due to simulated failure
+    html = result.assoc("common.html.html")
+    expect(html).not_to be_nil
+    expect(html.last).to eq("<b>Hi</b>")
+  end
+end