application_helper.rb

require 'ostruct'

module ApplicationHelper
  def pluralize(*args, &blk)
    result = super
    if block_given?
      count, *text = result.split
      yield OpenStruct.new(text: text.join(' '), count: count)
      nil
    else
      result
    end
  end
end

application_helper_spec.rb

require 'spec_helper'

describe ApplicationHelper do

  describe "#pluralize" do
    context "when no block given" do
      subject { pluralize(2, 'Cred') }

      it { should == "2 Creds" }
    end

    context "when block given" do
      subject do
        pluralize(2, 'Awesome Cred') { |p| p }
      end

      it { should be_blank }

      it "yields an object to use in the view" do
        pluralize(2, 'Awesome Cred') do |p|
          p.text.should == "Awesome Creds"
          p.count.should == "2"
        end
      end
    end
  end

end

usage.html.haml

= pluralize 5, 'Thing' do |p|
  %strong= p.count
  = p.text