From 2abee3fcddab4fbaab208ff11eae564c02abd6b3 Mon Sep 17 00:00:00 2001
From: Rohan Mitchell <rohan@rohanmitchell.com>
Date: Wed, 2 Mar 2016 11:01:41 +1100
Subject: [PATCH] Extract integrity checking to lib class

---
 .../products_cache_integrity_checker_job.rb   | 24 +++-------
 .../products_cache_integrity_checker.rb       | 44 +++++++++++++++++++
 lib/tasks/cache.rake                          |  6 +--
 3 files changed, 50 insertions(+), 24 deletions(-)
 create mode 100644 lib/open_food_network/products_cache_integrity_checker.rb

diff --git a/app/jobs/products_cache_integrity_checker_job.rb b/app/jobs/products_cache_integrity_checker_job.rb
index 5702380309..78feb3a1b0 100644
--- a/app/jobs/products_cache_integrity_checker_job.rb
+++ b/app/jobs/products_cache_integrity_checker_job.rb
@@ -1,31 +1,17 @@
-require 'open_food_network/products_renderer'
+require 'open_food_network/products_cache_integrity_checker'
 
 ProductsCacheIntegrityCheckerJob = Struct.new(:distributor_id, :order_cycle_id) do
   def perform
-    if diff.any?
-      Bugsnag.notify RuntimeError.new("Products JSON differs from cached version for distributor: #{distributor_id}, order cycle: #{order_cycle_id}"), diff: diff.to_s(:text)
+    unless checker.ok?
+      Bugsnag.notify RuntimeError.new("Products JSON differs from cached version for distributor: #{distributor_id}, order cycle: #{order_cycle_id}"), diff: checker.diff.to_s(:text)
     end
   end
 
 
   private
 
-  def diff
-    @diff ||= Diffy::Diff.new pretty(cached_json), pretty(rendered_json)
-  end
-
-  def pretty(json)
-    JSON.pretty_generate JSON.parse json
-  end
-
-  def cached_json
-    Rails.cache.read("products-json-#{distributor_id}-#{order_cycle_id}") || {}.to_json
-  end
-
-  def rendered_json
-    OpenFoodNetwork::ProductsRenderer.new(distributor, order_cycle).products_json
-  rescue OpenFoodNetwork::ProductsRenderer::NoProducts
-    nil
+  def checker
+    OpenFoodNetwork::ProductsCacheIntegrityChecker.new(distributor, order_cycle)
   end
 
   def distributor
diff --git a/lib/open_food_network/products_cache_integrity_checker.rb b/lib/open_food_network/products_cache_integrity_checker.rb
new file mode 100644
index 0000000000..cf8363ee5c
--- /dev/null
+++ b/lib/open_food_network/products_cache_integrity_checker.rb
@@ -0,0 +1,44 @@
+require 'open_food_network/products_renderer'
+
+module OpenFoodNetwork
+  class ProductsCacheIntegrityChecker
+    def initialize(distributor, order_cycle)
+      @distributor = distributor
+      @order_cycle = order_cycle
+    end
+
+    def ok?
+      diff.none?
+    end
+
+    def diff
+      @diff ||= Diffy::Diff.new pretty(cached_json), pretty(rendered_json)
+    end
+
+
+    def self.active_exchanges
+      Exchange.
+        outgoing.
+        joins(:order_cycle).
+        merge(OrderCycle.dated).
+        merge(OrderCycle.not_closed)
+    end
+
+
+    private
+
+    def cached_json
+      Rails.cache.read("products-json-#{@distributor.id}-#{@order_cycle.id}") || {}.to_json
+    end
+
+    def rendered_json
+      OpenFoodNetwork::ProductsRenderer.new(@distributor, @order_cycle).products_json
+    rescue OpenFoodNetwork::ProductsRenderer::NoProducts
+      nil
+    end
+
+    def pretty(json)
+      JSON.pretty_generate JSON.parse json
+    end
+  end
+end
diff --git a/lib/tasks/cache.rake b/lib/tasks/cache.rake
index 7b20a69c6a..8a564fcddc 100644
--- a/lib/tasks/cache.rake
+++ b/lib/tasks/cache.rake
@@ -19,11 +19,7 @@ namespace :openfoodnetwork do
     private
 
     def active_exchanges
-      Exchange.
-        outgoing.
-        joins(:order_cycle).
-        merge(OrderCycle.dated).
-        merge(OrderCycle.not_closed)
+      ProductsCacheIntegrityChecker.active_exchanges
     end
   end
 end