[Proof of concept] Component isolation

lib/dry/system/loader.rb

@@ -41,16 +41,25 @@ def require!(component)
         # @return [Object]
         #
         # @api public
-        def call(component, *args)
+        def call(component, *args, isolate: false)
           require!(component)
 
           constant = self.constant(component)
 
-          if singleton?(constant)
+          instance = if singleton?(constant)
             constant.instance(*args)
           else
             constant.new(*args)
           end
+
+          if isolate
+            constant_name_parts = constant.to_s.split("::")
+            namespace = constant_name_parts.slice(0..-2).join("::")
+            namespace_const = component.inflector.constantize(namespace)
+            namespace_const.send(:remove_const, constant_name_parts.last)
+          end
+
+          instance
         end
         ruby2_keywords(:call) if respond_to?(:ruby2_keywords, true)
 

spec/unit/loader_spec.rb

@@ -71,6 +71,13 @@ module Test
       end
 
       it_behaves_like "object loader"
+
+      it "isolates component by removing its constant" do
+        constant
+        instance = loader.call(component, isolate: true)
+        expect(Test.const_defined?("Bar")).to eq(false)
+        expect(instance).to be_a(constant)
+      end
     end
 
     context "with a constructor accepting args" do