From 4b303bcc1bd9cd5bede04eaeb70207f471a38a6b Mon Sep 17 00:00:00 2001
From: patrick brisbin <pbrisbin@gmail.com>
Date: Thu, 27 Mar 2014 13:23:06 -0400
Subject: [PATCH] Add Invocation.invoke so we can access the result

Up until now, discarding the result was fine. Now that issue trackers
return urls to the created tickets, we need to preserve the result and
return it from any invocations.
---
 lib/cc/service/invocation.rb | 11 +++++++++--
 test/invocation_test.rb      | 20 ++++++++++++--------
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/lib/cc/service/invocation.rb b/lib/cc/service/invocation.rb
index 7c724bc..f643c0e 100644
--- a/lib/cc/service/invocation.rb
+++ b/lib/cc/service/invocation.rb
@@ -10,6 +10,8 @@ class CC::Service::Invocation
     error_handling: WithErrorHandling,
   }
 
+  attr_reader :result
+
   # Build a chain of invocation wrappers which eventually calls receive
   # on the given service, then execute that chain.
   #
@@ -17,7 +19,7 @@ class CC::Service::Invocation
   #
   # Usage:
   #
-  #   CC::Service::Invocation.new(service) do |i|
+  #   CC::Service::Invocation.invoke(service) do |i|
   #     i.with :retries, 3
   #     i.with :metrics, $statsd
   #     i.with :error_handling, Rails.logger
@@ -28,12 +30,17 @@ class CC::Service::Invocation
   # metrics collector, then up again to the error handling. If the order
   # were reversed, the error handling middleware would prevent the other
   # middleware from seeing any exceptions at all.
+  def self.invoke(service, &block)
+    instance = new(service, &block)
+    instance.result
+  end
+
   def initialize(service)
     @chain = InvocationChain.new { service.receive }
 
     yield(self) if block_given?
 
-    @chain.call
+    @result = @chain.call
   end
 
   def with(middleware, *args)
diff --git a/test/invocation_test.rb b/test/invocation_test.rb
index 1d89bc7..90e8d4a 100644
--- a/test/invocation_test.rb
+++ b/test/invocation_test.rb
@@ -2,11 +2,12 @@
 
 class TestInvocation < Test::Unit::TestCase
   def test_success
-    service = FakeService.new
+    service = FakeService.new(:some_result)
 
-    CC::Service::Invocation.new(service)
+    result = CC::Service::Invocation.invoke(service)
 
     assert_equal 1, service.receive_count
+    assert_equal :some_result, result
   end
 
   def test_retries
@@ -15,7 +16,7 @@ def test_retries
     error_occurred = false
 
     begin
-      CC::Service::Invocation.new(service) do |i|
+      CC::Service::Invocation.invoke(service) do |i|
         i.with :retries, 3
       end
     rescue
@@ -29,7 +30,7 @@ def test_retries
   def test_metrics
     statsd = FakeStatsd.new
 
-    CC::Service::Invocation.new(FakeService.new) do |i|
+    CC::Service::Invocation.invoke(FakeService.new) do |i|
       i.with :metrics, statsd, "a_prefix"
     end
 
@@ -44,7 +45,7 @@ def test_metrics_on_errors
     error_occurred = false
 
     begin
-      CC::Service::Invocation.new(service) do |i|
+      CC::Service::Invocation.invoke(service) do |i|
         i.with :metrics, statsd, "a_prefix"
       end
     rescue
@@ -61,7 +62,7 @@ def test_error_handling
     service = FakeService.new
     service.raise_on_receive = true
 
-    CC::Service::Invocation.new(service) do |i|
+    CC::Service::Invocation.invoke(service) do |i|
       i.with :error_handling, logger, "a_prefix"
     end
 
@@ -74,7 +75,7 @@ def test_multiple_middleware
     service.raise_on_receive = true
     logger = FakeLogger.new
 
-    CC::Service::Invocation.new(service) do |i|
+    CC::Service::Invocation.invoke(service) do |i|
       i.with :retries, 3
       i.with :error_handling, logger
     end
@@ -89,7 +90,8 @@ class FakeService
     attr_reader :receive_count
     attr_accessor :raise_on_receive
 
-    def initialize
+    def initialize(result = nil)
+      @result = result
       @receive_count = 0
     end
 
@@ -99,6 +101,8 @@ def receive
       if @raise_on_receive
         raise "Boom"
       end
+
+      @result
     end
   end