Closes #31.

VMDInstrumenter.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name         = 'VMDInstrumenter'
-  s.version      = '0.8.1'
+  s.version      = '0.9'
   s.summary      = 'A simple Objective-C singleton to instrument, trace, and suppress selectors at runtime.'
   s.author       = { 
     'Vittorio Monaco' => 'vittorio.monaco1@gmail.com' 

VMInstrumenter/VMDInstrumenter.m

@@ -284,6 +284,9 @@ - (void) traceSelector:(SEL)selectorToTrace forInstancesOfClass:(Class)classToIn
 
 - (void) protectSelector:(SEL)selectorToProtect onClass:(Class)classToInspect fromBeingCalledFromSourcesOtherThanStacktraceFramesPassingTest:(VMDFrameTestBlock)testBlock
 {
+    if(!classToInspect)
+        return;
+
     NSString *protectedSelectorName = [VMDHelper generatePlausibleSelectorNameForSelectorToProtect:selectorToProtect ofClass:classToInspect];
     if([self.protectedSelectors containsObject:protectedSelectorName])
         @throw [NSException exceptionWithName:NSInternalInconsistencyException

VMInstrumenter_Tests/VMInstrumenter_Tests.m

@@ -275,7 +275,30 @@ - (void) testOnBlock2
             });*/
 
             context(@"from being called from sources other than classes passing a specific test block", ^{
+                it(@"should do nothing if the class is nil", ^{
+                    [[theBlock(^{
+                        [_instrumenter protectSelector:@selector(dontCallMe)
+                                               onClass:nil fromBeingCalledFromSourcesOtherThanClassesPassingTest:^BOOL(__unsafe_unretained Class callingClass) {
+                                                   return YES;
+                                               }];
+                    }) shouldNot] raise];
+                });
 
+                it(@"should protect the selector if the class is valid", ^{
+                    [_instrumenter protectSelector:@selector(testOnClass2)
+                                           onClass:[ProtectHelper class] fromBeingCalledFromSourcesOtherThanClassesPassingTest:^BOOL(__unsafe_unretained Class callingClass) {
+                                               return [NSStringFromClass(callingClass) hasPrefix:@"Tests"];
+                                           }];
+                    ProtectHelper *helper = [ProtectHelper new];
+                    [[theBlock(^{
+                        [helper testOnClass2];
+                    }) shouldNot] raise];
+
+                    ProtectHelperChecker *checker = [ProtectHelperChecker new];
+                    [[theBlock(^{
+                        [checker callSelector:@selector(testOnClass2) onObject:helper];
+                    }) should] raise];
+                });
             });
         });