diff options
Diffstat (limited to 'lib/puppet/application')
| -rw-r--r-- | lib/puppet/application/face_base.rb | 45 |
1 files changed, 44 insertions, 1 deletions
diff --git a/lib/puppet/application/face_base.rb b/lib/puppet/application/face_base.rb index d02769412..69c3ad5ad 100644 --- a/lib/puppet/application/face_base.rb +++ b/lib/puppet/application/face_base.rb @@ -214,12 +214,55 @@ class Puppet::Application::FaceBase < Puppet::Application # Call the method associated with the provided action (e.g., 'find'). if @action begin + # We need to do arity checking here because this is generic code + # calling generic methods – that have argument defaulting. We need to + # make sure we don't accidentally pass the options as the first + # argument to a method that takes one argument. eg: + # + # puppet facts find + # => options => {} + # @arguments => [{}] + # => @face.send :bar, {} + # + # def face.bar(argument, options = {}) + # => bar({}, {}) # oops! we thought the options were the + # # positional argument!! + # + # We could also fix this by making it mandatory to pass the options on + # every call, but that would make the Ruby API much more annoying to + # work with; having the defaulting is a much nicer convention to have. + # + # We could also pass the arguments implicitly, by having a magic + # 'options' method that was visible in the scope of the action, which + # returned the right stuff. + # + # That sounds attractive, but adds complications to all sorts of + # things, especially when you think about how to pass options when you + # are writing Ruby code that calls multiple faces. Especially if + # faces are involved in that. ;) + # + # --daniel 2011-04-27 + if (arity = @action.positional_arg_count) > 0 + unless (count = arguments.length) == arity then + raise ArgumentError, "wrong number of arguments (#{count} for #{arity})" + end + end + result = @face.send(@action.name, *arguments) puts render(result) unless result.nil? status = true rescue Exception => detail puts detail.backtrace if Puppet[:trace] - Puppet.err detail.to_s + + case detail + when ArgumentError then + got, want = /\((\d+) for (\d+)\)/.match(detail.to_s).to_a.map {|x| x.to_i } + Puppet.err "puppet #{@face.name} #{@action.name}: #{want} argument expected but #{got} given" + Puppet.err "Try 'puppet help #{@face.name} #{@action.name}' for usage" + + else # generic exception handling, alas. + Puppet.err detail.to_s + end end else puts "#{face} does not respond to action #{arguments.first}" |