- use more let() statements instead of local scoping things

This is an attempt to fix two specs that clobber eachother, but it
  did not fix anything.
  Still, this is easier to read now.

spec/test_utils.rb

@@ -25,33 +25,33 @@ end
 module LogStash
   module RSpec
     def config(configstr)
-      @config_str = configstr
+      let(:config) { configstr }
     end # def config
 
     def type(default_type)
-      @default_type = default_type
+      let(:default_type) { default_type }
     end
     
     def tags(*tags)
-      @default_tags = tags
+      let(:default_tags) { tags }
       puts "Setting default tags: #{@default_tags}"
     end
 
-    def sample(event, &block)
-      pipeline = LogStash::Pipeline.new(@config_str)
-
-      name = event.is_a?(String) ? event : event.to_json
+    def sample(sample_event, &block)
+      name = sample_event.is_a?(String) ? sample_event : sample_event.to_json
       name = name[0..50] + "..." if name.length > 50
 
       describe "\"#{name}\"" do
-        before :each do
-          # Coerce to an array of LogStash::Event
-          event = [event] unless event.is_a?(Array)
-          event = event.collect do |e| 
+        let(:pipeline) { LogStash::Pipeline.new(config) }
+        let(:event) do
+          sample_event = [sample_event] unless sample_event.is_a?(Array)
+          next sample_event.collect do |e|
             e = { "message" => e } if e.is_a?(String)
             next LogStash::Event.new(e)
           end
+        end
 
+        let(:results) do
           results = []
           count = 0
           pipeline.instance_eval { @filters.each(&:register) }
@@ -66,19 +66,19 @@ module LogStash
 
           # TODO(sissel): pipeline flush needs to be implemented.
           #results += pipeline.flush
-          @results = results
-        end # before :all
+          next results
+        end
+
+        subject { results.length > 1 ? results: results.first }
 
-        subject { @results.length > 1 ? @results: @results.first }
         it("when processed", &block)
       end
     end # def sample
 
     def input(&block)
-      config_str = @config_str
       it "inputs" do
         queue = Queue.new
-        pipeline = LogStash::Pipeline.new(config_str)
+        pipeline = LogStash::Pipeline.new(config)
         #(class << pipeline; self; end).send(:define_method, :output) do |event|
           #p :event => event
           #queue << event
@@ -94,11 +94,10 @@ module LogStash
       require "logstash/pipeline"
 
       # scoping is hard, let's go shopping!
-      config_str = @config_str
       describe "agent(#{@agent_count}) #{caller[1]}" do
         before :each do
           start = ::Time.now
-          pipeline = LogStash::Pipeline.new(config_str)
+          pipeline = LogStash::Pipeline.new(config)
           pipeline.run
           @duration = ::Time.now - start
         end