A light-light-light-weight Double/Mock framework for Objective-C

Doubler.h

#import <Foundation/Foundation.h>
#import "NSObject+TestExtension.h"

@interface Doubler : NSObject {
}

+(id)named:(NSString *)name;

-(BOOL)shouldHaveReceived:(NSString *)message with:(id)parameter;
-(BOOL)shouldHaveReceived:(NSString *)message;

@end

Doubler.m

#import "Doubler.h"

@implementation Doubler

+(id)named:(NSString *)name {
	return [[[Doubler alloc] init] autorelease];
}

#pragma mark -
-(BOOL)shouldHaveReceived:(NSString *)message with:(id)parameter {
	NSArray *parameters = parameter;
	if (![parameter respondsToSelector:@selector(count)]) {
		parameters = [NSArray arrayWithObject:parameter];
	}
	return [[called objectForKey:message] isEqual:parameters];
}

-(BOOL)shouldHaveReceived:(NSString *)message {
	return [called objectForKey:message] != nil;
}

@end

DoublerTest.m

#import "GTMSenTestCase.h"

#import "Doubler.h"
#import "NSObject+TestExtension.h"

@interface DoublerTests : GTMTestCase { }
@end

@implementation DoublerTests
//Doubler should...

-(void) test_validate_an_expectation
{
	id doubler = [Doubler named:@"xpto"];
	NSString *method = @"entaroAdum:";
	NSString *parameter = @"parameter";
	
	[doubler entaroAdum:parameter];
	
	BOOL isExpectationValid = [doubler shouldHaveReceived:method with:parameter];
	STAssertTrue(isExpectationValid, @"Doubler instance should validate a method call with a parameter.");
}

@end

NSObject+TestExtension.h

#import <Foundation/Foundation.h>


@interface NSObject (TestExtension)

NSMutableDictionary *stubs;
NSMutableDictionary *called;

-(void)stub:(NSString *)method andReturn:(id)result;

@end

NSObject+TestExtension.m

#import "NSObject+TestExtension.h"


@implementation NSObject(TestExtension)

#pragma mark -
-(NSMutableDictionary *)stubs {
	if(stubs == nil) {
		stubs = [[NSMutableDictionary dictionary] retain];
	}
	return stubs;
}

-(NSMutableDictionary *)called {
	if(called == nil) {
		called = [[NSMutableDictionary dictionary] retain];
	}
	return called;
}

-(void)fazNada {
	NSLog(@"::: esse método não faz nada");
}

-(void)stub:(NSString *)method andReturn:(id)result {
	// checar se o método existe para substituir implementação
	SEL originalMethodSelector = NSSelectorFromString(method);
	BOOL methodExists = [self respondsToSelector:originalMethodSelector];
	if (methodExists) {
		//method_exchangeImplementations(originalMethodSelector, @selector(fazNada));
	}
	
	[[self stubs] setObject:result forKey:method];
}

-(id)returnTheValue:(NSString *)method {
	return [[self stubs] objectForKey:method];
}

#pragma mark -
#pragma mark missing methods
- (NSArray *)getParametersToInvocation:(NSInvocation *)invocation {
	NSArray *args = [NSStringFromSelector([invocation selector]) componentsSeparatedByString: @":"];
	
	NSMutableArray *parameters = [NSMutableArray array];
	for (int i=2; i<[args count]+1; i++) {
		NSString *arg;
		[invocation getArgument:&arg atIndex:i];
		
		// Workaround // not allowed to put nil in an array
		if (arg == nil) {
			arg = @"";
		}
		// pensar em uma forma melhor de armazenar isso...
		
		[parameters addObject:arg];
	}

	return [NSArray arrayWithArray:parameters];
}

-(void)invoke:(NSInvocation *)invocation andReturnValue:(id)value {
	[invocation setTarget:self];
	[invocation setSelector:@selector(returnTheValue:)];
	[invocation setArgument:value atIndex:3];
	[invocation invoke];
}

- (void)forwardInvocation:(NSInvocation *)invocation {
	NSString *selectorString = NSStringFromSelector([invocation selector]);
	[[self called] setObject:[self getParametersToInvocation:invocation] forKey:selectorString];
	
	BOOL isStubConfigured = [[self stubs] objectForKey:selectorString] != nil;
	if (isStubConfigured) {
		[self invoke:invocation andReturnValue:[[self stubs] objectForKey:selectorString]];
	}
}

- (NSMethodSignature *)methodSignatureForSelector:(SEL)selector
{
	return [NSMethodSignature signatureWithObjCTypes:"@^v@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"];;
}

@end