adding start / finish on the instrumenter, adding tests for the class

2 files changed, 67 insertions, 6 deletions

diff --git a/activesupport/lib/active_support/notifications/instrumenter.rb b/activesupport/lib/active_support/notifications/instrumenter.rb
index ab0b162ee0..1ee7ca06bb 100644
--- a/activesupport/lib/active_support/notifications/instrumenter.rb
+++ b/activesupport/lib/active_support/notifications/instrumenter.rb
@@ -7,7 +7,7 @@ module ActiveSupport
       attr_reader :id
 
       def initialize(notifier)
-        @id = unique_id
+        @id       = unique_id
         @notifier = notifier
       end
 
@@ -15,21 +15,32 @@ module ActiveSupport
       # and publish it. Notice that events get sent even if an error occurs
       # in the passed-in block.
       def instrument(name, payload={})
-        @notifier.start(name, @id, payload)
+        start name, payload
         begin
           yield
         rescue Exception => e
           payload[:exception] = [e.class.name, e.message]
           raise e
         ensure
-          @notifier.finish(name, @id, payload)
+          finish name, payload
         end
       end
 
+      # Send a start notification with +name+ and +payload+.
+      def start(name, payload)
+        @notifier.start name, @id, payload
+      end
+
+      # Send a finish notification with +name+ and +payload+.
+      def finish(name, payload)
+        @notifier.finish name, @id, payload
+      end
+
       private
-        def unique_id
-          SecureRandom.hex(10)
-        end
+
+      def unique_id
+        SecureRandom.hex(10)
+      end
     end
 
     class Event
diff --git a/activesupport/test/notifications/instrumenter_test.rb b/activesupport/test/notifications/instrumenter_test.rb
new file mode 100644
index 0000000000..62a9b61464
--- /dev/null
+++ b/activesupport/test/notifications/instrumenter_test.rb
@@ -0,0 +1,50 @@
+require 'abstract_unit'
+require 'active_support/notifications/instrumenter'
+
+module ActiveSupport
+  module Notifications
+    class InstrumenterTest < ActiveSupport::TestCase
+      class TestNotifier
+        attr_reader :starts, :finishes
+
+        def initialize
+          @starts   = []
+          @finishes = []
+        end
+
+        def start(*args);  @starts << args; end
+        def finish(*args); @finishes << args; end
+      end
+
+      attr_reader :instrumenter, :notifier, :payload
+
+      def setup
+        super
+        @notifier     = TestNotifier.new
+        @instrumenter = Instrumenter.new @notifier
+        @payload      =  { :foo => Object.new }
+      end
+
+      def test_instrument
+        called  = false
+        instrumenter.instrument("foo", payload) {
+          called = true
+        }
+
+        assert called
+      end
+
+      def test_start
+        instrumenter.start("foo", payload)
+        assert_equal [["foo", instrumenter.id, payload]], notifier.starts
+        assert_predicate notifier.finishes, :empty?
+      end
+
+      def test_finish
+        instrumenter.finish("foo", payload)
+        assert_equal [["foo", instrumenter.id, payload]], notifier.finishes
+        assert_predicate notifier.starts, :empty?
+      end
+    end
+  end
+end