ClassInformationService.classes_per_environment call for non-existent file does not return errors

If I pass a path to a manifest file that does not exist to the list of files to be parsed in a call to Puppet::InfoService::ClassInformationService.new.classes_per_environment, the return value just returns an empty array, as opposed to a hash with an :error key/value pair in it.

For example, running the following code...

require 'puppet'

require 'puppet/info_service'

files_to_parse = { "production" => [ "./parse.pp" ] }

puts Puppet::InfoService::ClassInformationService.new.classes_per_environment(files_to_parse)

... where "./parse.pp" does not exist produces the following output:

{"production"=>{"./parse.pp"=>[]}}

If instead I have a file that exists at "./parse.pp" which has bad content in it...

bogus manifest

... an :error is returned in a hash associated with the file name:

{"production"=>{"./parse.pp"=>{:error=>"This Name has no effect. A value was produced and then forgotten (one or more preceding expressions may have the wrong form) at ./parse.pp:1:1"}}}

It seems like both cases should result in an :error key being returned.