Merge pull request #378 from envato/improve_format_lines_for_cloudformation

Improve `#format_lines_for_cloudformation` for readability and performance

Author: orien

CHANGELOG.md

@@ -24,7 +24,7 @@ The format is based on [Keep a Changelog], and this project adheres to
 - Introduce `user_data_file`, `user_data_file_as_lines`, and `include_file`
   convenience methods to the YAML ERB template compiler ([#377]).
 
-[2.13.4]: https://github.com/envato/stack_master/compare/v2.13.4...v2.14.0
+[2.14.0]: https://github.com/envato/stack_master/compare/v2.13.4...v2.14.0
 [#375]: https://github.com/envato/stack_master/pull/375
 [#376]: https://github.com/envato/stack_master/pull/376
 [#377]: https://github.com/envato/stack_master/pull/377

lib/stack_master/cloudformation_interpolating_eruby.rb

@@ -50,10 +50,7 @@ def format_lines_for_cloudformation(source)
         lines = lines.to_s if lines.is_a?(Symbol)
         next(lines) unless lines.is_a?(String)
 
-        newlines = Array.new(lines.count("\n"), "\n")
-        newlines = lines.split("\n").map { |line| "#{line}#{newlines.pop}" }
-        newlines.insert(0, "\n") if lines.start_with?("\n")
-        newlines
+        lines.scan(/[^\n]*\n?/).reject { |x| x == '' }
       end
     end
   end