class Opal::BuilderProcessors::RubyERBProcessor

first get preprocessed via ERB, then via Opal.
This handler is for files named “.rb.erb”, which ought to

def compiled 

def compiled
  @compiled ||= begin
    @source = ::ERB.new(@source.to_s).result
    compiler = compiler_for(@source, file: @filename)
    compiler.compile
    compiler
  end
end