Set the locale to "en" in test environment.

config/environments/test.rb

@@ -33,6 +33,9 @@ Openfoodnetwork::Application.configure do
   # ActionMailer::Base.deliveries array.
   config.action_mailer.delivery_method = :test
 
+  # Tests assume English text on the site.
+  config.i18n.default_locale = "en"
+
   # Use SQL instead of Active Record's schema dumper when creating the test database.
   # This is necessary if your schema can't be completely dumped by the schema dumper,
   # like if you have constraints or database-specific column types