Improve unit tests for StoppableSGObject.

tests/unit/lib/StoppableSGObject_unittest.cc

@@ -13,26 +13,28 @@
 using namespace shogun;
 using namespace std;
 
-class Mock_model : public CMachine
+/**
+ * Mock model to show the use of the callback.
+ */
+class MockModel : public CMachine
 {
 public:
-	Mock_model() : m_check(0), m_i(0)
+	MockModel() : m_check(0), m_last_iteration(0)
 	{
 		// Set up the custom callback
 		function<bool()> callback = [this]()
 		{
 			// Stop if we did more than 5 steps
-			if (m_i >= 5)
+			if (m_last_iteration >= 5)
 			{
 				get_global_signal()->get_subscriber()->on_next(SG_BLOCK_COMP);
 				return true;
 			}
-			m_i++;
+			m_last_iteration++;
 			return false;
 		};
 
-		// We then add the callback
-		this->add_callback(callback);
+		this->set_callback(callback);
 	};
 
 	int get_check()
@@ -48,28 +50,39 @@ class Mock_model : public CMachine
 
 protected:
 
-	/** returns whether machine require labels for training */
 	virtual bool train_require_labels() const { return false; }
 
-	// Custom train machine
+	/* Custom train machine */
 	virtual bool train_machine(CFeatures* data=NULL)
 	{
-		for (int k=0; k<10; k++)
+		for (int num_iterations_train=0; num_iterations_train<10; num_iterations_train++)
 		{
 			COMPUTATION_CONTROLLERS
 			m_check++;
 		}
 		return true;
 	}
+
+	/* Control variable, used to check that we stopped the training at the
+	 * exact number of iterations (it will be equal to m_last_iteration)*/
 	int m_check;
-	int m_i;
+
+	/* Addition control variable that is incremented each time by the callback.*/
+	int m_last_iteration;
 };
 
 
+TEST(StoppableSGObject, empty_callback)
+{
+	MockModel a;
+	a.set_callback(nullptr);
+	a.train();
+	EXPECT_TRUE(a.get_check() == 10);
+}
 
-TEST(StoppableSGObject, custom_callback)
+TEST(StoppableSGObject, default_callback)
 {
-	Mock_model a;
+	MockModel a;
 	a.train();
 	EXPECT_TRUE(a.get_check() == 5);
 }
@@ -88,8 +101,8 @@ TEST(StoppableSGObject, custom_callback_by_user)
 	};
 
 
-	Mock_model a;
-	a.add_callback(callback);
+	MockModel a;
+	a.set_callback(callback);
 	a.train();
 	EXPECT_TRUE(a.get_check() == 3);
 }