brainstorming: how to implement the test mock injection

2013-10-19 23:37:00 +02:00 · 2013-10-19 23:37:00 +02:00 · 24792c1f19
commit 24792c1f19
parent 739a473f7e
1 changed files with 28 additions and 9 deletions
--- a/src/lib/dependency-factory.cpp
+++ b/src/lib/dependency-factory.cpp
@ -84,15 +84,34 @@ namespace lib {
    
    
    
-//    struct TemporarySwitch
-//      {
-//        void*           originalInstance;
-//        InstanceConstructor originalCtor;
-//      };
-//    
-//    static TemporarySwitch temporarySwitch;
-
-
+    class TemporaryShadowedInstanceFactory
+      : boost::noncopyable
+      {
+        typedef DependencyFactory::InstanceConstructor Ctor;
+        
+        void* originalInstance_;
+        Ctor  originalCtor_;
+        
+      public:
+        TemporaryShadowedInstanceFactory(void* instance, Ctor ctor)
+          : originalInstance_(instance)
+          , originalCtor_(ctor)
+          { }
+        
+        void*
+        constructorInvocation()
+          {
+            REQUIRE (originalCtor_);
+            
+            if (!originalInstance_)
+              return originalCtor_();
+            
+            void* existingInstance = originalInstance_;
+            originalInstance_ = NULL;
+            return existingInstance;
+          }
+      };
+      
  }