rakefile.rb

require 'yui-utils'
    
task :default, [:file, :replace, :filter, :jsdir] do |t, args|
    args.with_defaults(
        :filter => nil,
        :jsdir => nil,
        :replace => nil
    )
    
    modules = YUIUtils.build_module_list(args.filter, args.jsdir)
    
    YUIUtils.output(modules, args.file, args.replace)
end

yui-utils.rb

class YUIUtils
    @@module_regex = /YUI\.add\((['"][\w\-]+['"]).*\}, ['"].+['"], \{\s*(.+)\s*\}\);?/mi
    
    def self.build_module_list(filter = "**/*.js", jsdir = "Public/js")
        out = []
        
        FileList[filter].each do |file|
            match = File.read(file).scan(@@module_regex)
            if match[0] && match[0][0] && match[0][1] #filter out files that didn't match
                #prettier names
                yuimodule = match[0][0]
                config = match[0][1]
                
                out.push(%(\t#{yuimodule} : {\n\t\t"path" : "#{file.gsub(jsdir, "")}",\n\t\t#{config}\n\t}))
            end
        end
        
        "{\n#{out.join(",\n")}\n}"
    end
    
    def self.output(modules, filename, replace = false)
        File.open(filename, "r+") do |file|
            contents = (replace) ? file.read.gsub(replace, modules) : modules
            file.puts(contents)
        end
    end
end