Add Smithy::ServiceLocator module for when constructor injection is not ...

lib/smithy/service_locator.rb

@@ -0,0 +1,29 @@
+require "smithy/container"
+
+module Smithy
+  module ServiceLocator
+    class << self
+      attr_reader :container
+
+      def included(base)
+        base.extend(ClassMethods)
+      end
+
+      def register_container(container)
+        @container = container
+      end
+    end
+
+    module ClassMethods
+      private
+
+      def dependency(name)
+        define_method name do
+          ServiceLocator.container.instance(name)
+        end
+
+        private name
+      end
+    end
+  end
+end

spec/smithy/service_locator_spec.rb

@@ -0,0 +1,35 @@
+require "smithy/service_locator"
+
+describe Smithy::ServiceLocator do
+  class Dependency
+    def value
+      :expected_result
+    end
+  end
+
+  class ExampleServiceLocator
+    include Smithy::ServiceLocator
+
+    dependency :foo
+
+    def test
+      foo.value
+    end
+  end
+
+  let(:container) { Smithy::Container.new }
+  let(:test_object) { ExampleServiceLocator.new }
+
+  before do
+    container.register(:foo, Dependency)
+    Smithy::ServiceLocator.register_container(container)
+  end
+
+  it "provides requested dependencies" do
+    test_object.test.should == :expected_result
+  end
+
+  it "makes the dependencies private" do
+    test_object.private_methods.should include(:foo)
+  end
+end