Check sidecar key existence instead of catching MissingTranslation

Use I18nBackend#exists? to decide between sidecar and global
translations in both the class and instance translate methods, rather
than catching I18n's internal :exception throw. This also fixes
`default:` shadowing existing global translations, since the sidecar
backend applied the default before the fallback could run.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: ba89fbcb-d0e9-4f12-8673-169fbe391979

Author: joelhawksley

docs/CHANGELOG.md

@@ -10,7 +10,7 @@ nav_order: 6
 
 ## main
 
-* Fix `Component.translate` raising `UncaughtThrowError` for keys missing from the sidecar translations, and `NoMethodError` for components without sidecar translations. It now falls back to the global translations, like the instance method does.
+* Fix `Component.translate` raising `UncaughtThrowError` for keys missing from the sidecar translations, and `NoMethodError` for components without sidecar translations. It now falls back to the global translations, like the instance method does. Fix `translate` returning the `default:` value instead of an existing global translation.
 
     *Andrii Furmanets*
 

lib/view_component/translatable.rb

@@ -59,16 +59,11 @@ def translate(key = nil, **options)
         locale = options.delete(:locale) || ::I18n.locale
         key = __vc_i18n_key(key, options.delete(:scope))
 
-        if __vc_i18n_backend
-          translated = catch(:exception) do
-            __vc_i18n_backend.translate(locale, key, options)
-          end
-
-          return translated unless translated.is_a?(::I18n::MissingTranslation)
+        if __vc_i18n_backend&.exists?(locale, key)
+          __vc_i18n_backend.translate(locale, key, options)
+        else
+          ::I18n.translate(key, locale: locale, **options)
         end
-
-        # Fallback to the global translations
-        ::I18n.translate(key, locale: locale, **options)
       end
 
       alias_method :t, :translate
@@ -111,17 +106,8 @@ def translate(key = nil, **options)
 
       __vc_html_escape_translation_options!(options) if as_html
 
-      if key.start_with?(__vc_i18n_scope + ".")
-        translated =
-          catch(:exception) do
-            __vc_i18n_backend.translate(locale, key, options)
-          end
-
-        # Fallback to the global translations
-        if translated.is_a? ::I18n::MissingTranslation
-          return @view_context.translate(key, locale: locale, **options)
-        end
-
+      if __vc_i18n_backend.exists?(locale, key)
+        translated = __vc_i18n_backend.translate(locale, key, options)
         translated = __vc_html_safe_translation(translated) if as_html
         translated
       else

test/sandbox/test/translatable_test.rb

@@ -181,6 +181,16 @@ def test_translating_from_the_class_without_sidecar_translations
     assert_equal "This is coming from Rails", MyComponent.translate("from.rails")
   end
 
+  def test_default_does_not_shadow_global_translations
+    assert_equal "This is coming from Rails", TranslatableComponent.t("from.rails", default: "Default")
+    assert_equal "Relative key from Rails", TranslatableComponent.t(".relative_rails_key", default: "Default")
+    assert_equal "Default", TranslatableComponent.t(".missing", default: "Default")
+
+    assert_equal "This is coming from Rails", translate("from.rails", default: "Default")
+    assert_equal "Relative key from Rails", translate(".relative_rails_key", default: "Default")
+    assert_equal "Default", translate(".missing", default: "Default")
+  end
+
   def test_inheriting_and_overriding_translations
     render_inline(TranslatableSubclassComponent.new)