add more options for passing Faraday::Builder instances around

lib/faraday/builder.rb

@@ -9,20 +9,29 @@ module Faraday
   class Builder
     attr_accessor :handlers
 
-    def self.create_with_inner_app(&block)
-      inner = lambda do |env| 
-        if !env[:parallel_manager]
-          env[:response].finish(env)
-        else
-          env[:response]
-        end
-      end
-      Builder.new(&block).tap { |builder| builder.run(inner) }
+    def self.create(&block)
+      Builder.new(&block)
     end
 
-    def initialize(handlers = [])
+    def self.inner_app
+      lambda do |env| 
+        env[:parallel_manager] ? env[:response] : env[:response].finish(env)
+      end
+    end
+
+    def initialize(handlers = [], &block)
       @handlers = handlers
-      yield self if block_given?
+      build(&block) if block_given?
+    end
+
+    def build(&block)
+      block.call(self)
+      run(self.class.inner_app)
+    end
+
+    def [](index)
+      # @handlers are stored in reverse order
+      @handlers[-(index+1)]
     end
 
     def run(app)
@@ -35,7 +44,7 @@ module Faraday
     end
 
     def use(klass, *args, &block)
-      @handlers.unshift(lambda { |app| klass.new(app, *args, &block) })
+      run(lambda { |app| klass.new(app, *args, &block) })
     end
 
     def request(key, *args, &block)

lib/faraday/connection.rb

@@ -33,12 +33,16 @@ module Faraday
       merge_params  @params,  options[:params]  if options[:params]
       merge_headers @headers, options[:headers] if options[:headers]
       if block
-        @builder = Builder.create_with_inner_app(&block)
+        @builder = Builder.create(&block)
       else
         @builder = options[:builder] || Builder.new
       end
     end
 
+    def build(&block)
+      @builder.build(&block)
+    end
+
     def get(url = nil, headers = nil, &block)
       run_request :get, url, nil, headers, &block
     end

test/connection_app_test.rb

@@ -35,11 +35,26 @@ class TestConnectionApps < Faraday::TestCase
   end
 
   def test_builder_adds_middleware_to_builder_stack
-    assert_kind_of TestMiddleWare, @conn.builder.handlers[2].call(nil)
-    assert_kind_of TestAdapter,    @conn.builder.handlers[1].call(nil)
+    assert_kind_of TestMiddleWare, @conn.builder[0].call(nil)
+    assert_kind_of TestAdapter,    @conn.builder[1].call(nil)
   end
 
   def test_to_app_returns_rack_object
     assert @conn.to_app.respond_to?(:call)
   end
+
+  def test_builder_is_passed_to_new_faraday_connection
+    new_conn = Faraday::Connection.new :builder => @conn.builder
+    assert_equal @conn.builder, new_conn.builder
+  end
+
+  def test_builder_is_built_on_new_faraday_connection
+    new_conn = Faraday::Connection.new
+    new_conn.build do |b|
+      b.run @conn.builder[0]
+      b.run @conn.builder[1]
+    end
+    assert_kind_of TestMiddleWare, new_conn.builder[0].call(nil)
+    assert_kind_of TestAdapter,    new_conn.builder[1].call(nil)
+  end
 end