Convert ERB files to Ruby structures that can generate AST

[andreimid]

• Attempts to convert ERB file to a HEREDOC string that can be parsed and an AST can be generated from
• Falls back to wrapping the entire file in a HEREDOC if the transformation fails

app_name: <%= ENV['APP_NAME'] %>
version: <%= ENV['APP_VERSION'] %>

database:
  host: <%= ENV['DB_HOST'] %>
  port: <%= ENV['DB_PORT'] %>

<% if ENV['USE_REDIS'] == 'true' %>
redis:
  host: <%= ENV['REDIS_HOST'] %>
  port: <%= ENV['REDIS_PORT'] %>
<% end %>

Gets converted to:

<<~HEREDOC
  app_name: #{ENV['APP_NAME']}
  version: #{ENV['APP_VERSION']}
  database:
    host: #{ENV['DB_HOST']}
    port: #{ENV['DB_PORT']}
  #{
    if ENV['USE_REDIS'] == 'true'
      "redis:\n  host: #{ENV['REDIS_HOST']}\n  port: #{ENV['REDIS_PORT']}"
    else
      ""
    end
  }
HEREDOC

[DavidBakerEffendi]

Could you also add some tests to basically check the cases where the transform works and where it doesn't? No need to test the resulting ASTs