Merge pull request #17676 from tigrish/fix_custom_i18n_exception_handler_regression

Fix I18n regression introduced by #13832

actionview/lib/action_view/helpers/translation_helper.rb

@@ -39,12 +39,14 @@ module ActionView
         remaining_defaults = Array(options.delete(:default))
         options[:default] = remaining_defaults.shift if remaining_defaults.first.kind_of? String
 
-        # If the user has specified rescue_format then pass it all through, otherwise use
-        # raise and do the work ourselves
-        options[:raise] ||= ActionView::Base.raise_on_missing_translations
-
-        raise_error = options[:raise] || options.key?(:rescue_format)
-        unless raise_error
+        # If the user has explicitly decided to NOT raise errors, pass that option to I18n.
+        # Otherwise, tell I18n to raise an exception, which we rescue further in this method.
+        # Note: `raise_error` refers to us re-raising the error in this method. I18n is forced to raise by default.
+        if options[:raise] == false || (options.key?(:rescue_format) && options[:rescue_format].nil?)
+          raise_error = false
+          options[:raise] = false
+        else
+          raise_error = options[:raise] || options[:rescue_format] || ActionView::Base.raise_on_missing_translations
           options[:raise] = true
         end
 

actionview/test/template/translation_helper_test.rb

@@ -1,5 +1,13 @@
 require 'abstract_unit'
 
+module I18n
+  class CustomExceptionHandler
+    def self.call(exception, locale, key, options)
+      'from CustomExceptionHandler'
+    end
+  end
+end
+
 class TranslationHelperTest < ActiveSupport::TestCase
   include ActionView::Helpers::TranslationHelper
 
@@ -68,6 +76,22 @@ class TranslationHelperTest < ActiveSupport::TestCase
     end
   end
 
+  def test_uses_custom_exception_handler_when_specified
+    old_exception_handler = I18n.exception_handler
+    I18n.exception_handler = I18n::CustomExceptionHandler
+    assert_equal 'from CustomExceptionHandler', translate(:"translations.missing", raise: false)
+  ensure
+    I18n.exception_handler = old_exception_handler
+  end
+
+  def test_uses_custom_exception_handler_when_specified_for_html
+    old_exception_handler = I18n.exception_handler
+    I18n.exception_handler = I18n::CustomExceptionHandler
+    assert_equal 'from CustomExceptionHandler', translate(:"translations.missing_html", raise: false)
+  ensure
+    I18n.exception_handler = old_exception_handler
+  end
+
   def test_i18n_translate_defaults_to_nil_rescue_format
     expected = 'translation missing: en.translations.missing'
     assert_equal expected, I18n.translate(:"translations.missing")