Add storage to the deferred context

this is a storage hidden from the tasks that can be used by instrumentation code and middleware to pass data to each other without exposing it to the user

Author: rsamoilov

lib/rage/deferred/context.rb

@@ -13,7 +13,8 @@ def self.build(task, args, kwargs, storage: nil)
       args.empty? ? nil : args,
       kwargs.empty? ? nil : kwargs,
       nil,
-      request_id
+      request_id,
+      storage
     ]
   end
 
@@ -40,4 +41,8 @@ def self.inc_attempts(context)
   def self.get_request_id(context)
     context[4]
   end
+
+  def self.get_storage(context)
+    context[5]
+  end
 end

spec/deferred/context_spec.rb

@@ -85,4 +85,23 @@
       expect(context[3]).to eq(4)
     end
   end
+
+  describe ".get_storage" do
+    context "with empty storage" do
+      it "returns the storage object from context" do
+        context = described_class.build(nil, [], {})
+
+        expect(described_class.get_storage(context)).to be_nil
+      end
+    end
+
+    context "wit non-empty storage" do
+      it "returns the storage object from context" do
+        storage = { test: true }
+        context = described_class.build(nil, [], {}, storage: storage)
+
+        expect(described_class.get_storage(context)).to eq(storage)
+      end
+    end
+  end
 end