Forgeries

Forgeries is a library that makes unit testing iOS applications easier. UIKit has lots of limitations that make sense in production code, but make testing difficult. Forgeries fixes that problem.

Usage

Currently, the library provides subclasses of the standard gesture recognizers, as well as a replacement for NSUserDefaults.

Gesture Recognizers

The following are Forgeries' subclasses for gesture recognizers.

• ForgeryTapGestureRecognizer
• ForgeryPinchGestureRecognizer
• ForgeryRotationGestureRecognizer
• ForgerySwipeGestureRecognizer
• ForgeryPanGestureRecognizer
• ForgeryScreenEdgeGestureRecognizer
• ForgeryLongPressGestureRecognizer

These subclasses keep track of the number of times they've invoked their targets' actions; a handy interface to UIGestureRecognizer is provided:

@interface UIGestureRecognizer (Forgeries)

- (void)invoke;

@end

User Defaults

There is also a replacement for NSUserDefaults named ForgeriesUserDefaults. Use this instead of modifying the standardUserDefaults singleton.

The replacement also includes an optional replaceStandardUserDefaultsWith:, which uses OCMock. You need to separately install OCMock in order to use this.

Or, you can (and should) do the following...

Dependency Injection

The trick is to use Forgeries in testing only. A great way to do this is via Dependency Injection. This means injecting a dependency into an instance, instead of having that instance create the dependency itself, or access shared state. Let's take a look at an example.

Say you're testing MyViewController, you'd use lazy loading for your recognizer.

@interface MyViewController ()

@property (nonatomic, strong) UITapGestureRecognizer *recognizer;

@end

@implementation MyViewController

...

- (UITapGestureRecognizer *)recognizer {
	if (_recognizer == nil) {
		_recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleGestureRecognizer:)];
	}

	return _recognizer;
}

...

What we need to do is set that property before it is lazily loaded. Here's our testing code:

MyViewController *subject = /* Instantiate somehow */
ForgeryTapGestureRecognizer *recognizer = [[ForgeryTapGestureRecognizer alloc] initWithTarget:subject action:@selector(handleGestureRecognizer:)];
subject.recognizer = recognizer;

/* Optionally, set the testing_location and testing_velocity properties on recognizer. */

[recognizer invoke];

expect(subject).to( /* have done something, whatever it is you're testing for */ );

Requirements

Requires iOS 7 or higher.

Installation

Forgeries is available through CocoaPods. To install it, simply add the following line to your Podfile under the unit testing target:

target 'MyApp_Tests' do

  pod 'forgeries'

  ...

end

Now import the library in your unit tests.

import Forgeries

@import Forgeries;
// or #import <Forgeries/Forgeries.h>

Author

Ash Furrow, ash@ashfurrow.com Orta Therox, orta.therox@gmail.com

License

Forgeries is available under the MIT license. See the LICENSE file for more info.