Allow setting redis client

lib/shipit.rb

@@ -108,6 +108,10 @@ def redis
     )
   end
 
+  def redis=(client)
+    @redis ||= client
+  end
+
   module SafeJSON
     class << self
       def load(serial)

test/unit/shipit_test.rb

@@ -28,5 +28,51 @@ class ShipitTest < ActiveSupport::TestCase
       Shipit.github.stubs(:oauth_teams).returns(['shopify/developers'])
       assert_equal(['shopify/developers'], Shipit.github_teams.map(&:handle))
     end
+
+    class RedisTest < self
+      setup do
+        @client = mock(:client)
+      end
+
+      teardown do
+        Shipit.instance_variables.each(&Shipit.method(:remove_instance_variable))
+        Redis.unstub(:new)
+      end
+
+      test ".redis should build a new redis client" do
+        Redis.expects(:new).with(
+          has_entries(
+            url: "redis://127.0.0.1:6379/7",
+            reconnect_attempts: 3,
+            reconnect_delay: 0.5,
+            reconnect_delay_max: 1
+          )
+        ).returns(@client)
+
+        assert_equal(@client, Shipit.redis)
+      end
+
+      test ".redis should return an existing redis client" do
+        Redis.expects(:new).once.returns(@client)
+
+        2.times do
+          assert_equal(@client, Shipit.redis)
+        end
+      end
+
+      test ".redis= should set the redis client" do
+        Shipit.redis = @client
+
+        assert_equal(@client, Shipit.redis)
+      end
+
+      test ".redis= should set and memoize the redis client" do
+        Shipit.redis = @client
+
+        Redis.expects(:new).never
+
+        assert_equal(@client, Shipit.redis)
+      end
+    end
   end
 end