Error when ignoreNonObjectArgs is unnecessary.

This encourages proper use of the APIS and keeps the testing code cleaner and easier to
read.

Author: dmaclach

Source/OCMock/OCMInvocationMatcher.m

@@ -45,6 +45,7 @@ - (void)setInvocation:(NSInvocation *)anInvocation
     // anInvocation contains self as an argument, -retainArguments would create a retain cycle.
     [anInvocation retainObjectArgumentsExcludingObject:self];
     recordedInvocation = [anInvocation retain];
+    [self verifyInvocationCompatibleWithIgnoreNonObjectArgs];
 }
 
 - (void)setRecordedAsClassMethod:(BOOL)flag
@@ -60,6 +61,7 @@ - (BOOL)recordedAsClassMethod
 - (void)setIgnoreNonObjectArgs:(BOOL)flag
 {
     ignoreNonObjectArgs = flag;
+    [self verifyInvocationCompatibleWithIgnoreNonObjectArgs];
 }
 
 - (NSString *)description
@@ -142,4 +144,27 @@ - (BOOL)matchesInvocation:(NSInvocation *)anInvocation
     return YES;
 }
 
+- (void)verifyInvocationCompatibleWithIgnoreNonObjectArgs 
+{
+    if (!recordedInvocation || !ignoreNonObjectArgs) 
+    {
+        return;
+    }
+    NSMethodSignature *signature = [recordedInvocation methodSignature];
+    NSUInteger n = [signature numberOfArguments];
+    BOOL foundNonObjectArg = NO;
+    for(NSUInteger i = 2; i < n; i++)
+    {
+        if(!OCMIsObjectType([signature getArgumentTypeAtIndex:i]))
+        {
+            foundNonObjectArg = YES;
+            break;
+        }
+    }
+    if (!foundNonObjectArg) 
+    {
+        [NSException raise:NSInvalidArgumentException format:@"Method `%@` with %@ marked as ignoreNonObjectArgs.", NSStringFromSelector([recordedInvocation selector]), n == 2 ? @"0 args" : @"only object args"];
+    }
+}
+
 @end

Source/OCMockTests/OCMockObjectTests.m

@@ -465,14 +465,38 @@ - (void)testRaisesExceptionWhenMethodWithMixedArgumentsIsCalledWithWrongObjectAr
 
 - (void)testBlocksAreNotConsideredNonObjectArguments
 {
-    [[[mock stub] ignoringNonObjectArgs] enumerateLinesUsingBlock:[OCMArg invokeBlock]];
+    mock = [OCMockObject mockForClass:[NSArray class]];
+    [[[mock stub] ignoringNonObjectArgs] enumerateObjectsWithOptions:0 usingBlock:[OCMArg invokeBlock]];
     __block BOOL blockWasInvoked = NO;
-    [mock enumerateLinesUsingBlock:^(NSString * _Nonnull line, BOOL * _Nonnull stop) {
+    [mock enumerateObjectsWithOptions:5 usingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
         blockWasInvoked = YES;
     }];
     XCTAssertTrue(blockWasInvoked, @"Should not have ignored the block argument.");
 }
 
+- (void)testRaisesExceptionWhenIgnoringNonObjectArgumentsOnMethodThatHasZeroArgs
+{
+    @try
+    {
+        [[[mock stub] ignoringNonObjectArgs] uppercaseString];
+    }
+    @catch (NSException *e)
+    {
+        XCTAssertTrue([[e reason] containsString:@"0 args"]);
+    }
+}
+
+- (void)testRaisesExceptionWhenIgnoringNonObjectArgumentsOnMethodThatOnlyTakesObjects
+{
+    @try
+    {
+        [[[mock stub] ignoringNonObjectArgs] stringByAppendingString:[OCMArg any]];
+    }
+    @catch (NSException *e)
+    {
+        XCTAssertTrue([[e reason] containsString:@"only object args"]);
+    }
+}
 
 #pragma mark    returning values from stubbed methods