Avoid using heredoc for user warnings

Using heredoc would enforce line wrapping to whatever column width we decided to
use in the code, making it difficult for the users to read on some consoles.

This does make the source code read slightly worse and a bit more error-prone,
but this seems like a fair price to pay since the primary purpose for these
messages are for the users to read and the code will not stick around for too
long.

1 files changed, 3 insertions, 4 deletions

diff --git a/activerecord/lib/active_record/attribute_methods/serialization.rb b/activerecord/lib/active_record/attribute_methods/serialization.rb
index 264ce2bdfa..100d6d4229 100644
--- a/activerecord/lib/active_record/attribute_methods/serialization.rb
+++ b/activerecord/lib/active_record/attribute_methods/serialization.rb
@@ -54,10 +54,9 @@ module ActiveRecord
         end
 
         def serialized_attributes
-          ActiveSupport::Deprecation.warn(<<-WARNING.strip_heredoc)
-            `serialized_attributes` is deprecated without replacement, and will
-            be removed in Rails 5.0.
-          WARNING
+          ActiveSupport::Deprecation.warn "`serialized_attributes` is deprecated " \
+            "without replacement, and will be removed in Rails 5.0."
+
           @serialized_attributes ||= Hash[
             columns.select { |t| t.cast_type.is_a?(Type::Serialized) }.map { |c|
               [c.name, c.cast_type.coder]