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Unit Testing and Mocking for iPhone Apps

Posted by Doug Fri, 06 Feb 2009 20:54:00 GMT

This was so much harder than I expected it to be. I’m new to Objective-C, but a long time TDD-er with Ruby. Being able to write unit tests and mocks is an integral part of any language I work with now. After much searching and trial and error I got it to work.

First, starting with a new iPhone application I followed these directions on how to get it setup. The Sen:Te guys are who wrote OCUnit in the first place. There are other directions out there, but don’t let them lead you astray. XCode 3 doesn’t support unit testing iPhone applications out of the box. Most of the directions for setting up unit testing is for straight Mac OS X Cocoa apps and not iPhone apps. The gist of the directions are:

• Add a new target based on Mac OS X Cocoa Unit Test Bundle.
• In the new test target’s inspector window, whack all the “User-Defined Settings” in the new build tab’s settings.
• Also delete the ‘‘Other Linker Flags’ setting.
• In the General tab, add a dependency to the SenTestingKit.framework. Here’s where it gets tricky. Don’t just add any SenTestingKit.framework. You need to add the one from:

I also added a “Unit Tests” group/folder to the project as a place to store my tests separate from my classes. When you want to create a new test, you simply add a new file and choose the “Objective-C test case class” template. Make sure you add it to the test target and not your main application target.

So that gives you unit tests so you can make assertions; but that’s about it. You also need OCMock. I had a little trouble getting this installed and working, but following Mitchell Hasimoto’s notes I was able to get it working. Download the OCMock framework and save it into /Library/Frameworks. Then in you test target’s inspector add it as a dependency. That should be enough. Here’s a little test class that I used to prove to myself it was working:

testTruth.h:

#import <SenTestingKit/SenTestingKit.h>

@interface testTruth : SenTestCase {

}

- (void) testTruth;
- (void)testAcceptsStubbedMethod;

@end

TestTruth.m:

#import "testTruth.h"
#import <OCMock/OCMock.h>

@implementation testTruth

- (void) testTruth {
    STAssertTrue(1 == 1, @"Must be true");
}

- (void)testAcceptsStubbedMethod {
    id mock = [OCMockObject mockForClass:[NSString class]];
    [[mock stub] lowercaseString];
    [mock lowercaseString];
}
@end

Posted in Programming, Test Driven Development | Tags iPhone, mocks, testing | no comments

Simple Expense Tracking with Google Docs

Posted by Doug Mon, 28 Apr 2008 17:57:00 GMT

As my family prepares for our pending Disney trip, I’m thinking about clever ways to take advantage of my wife’s iPhone. One of the things we’ve done is budget the trip based on a few simple categories of expenses. There’s a lot of ways to track expenses to budgets, but I’m particularly happy with how this worked out using Google Documents and the iPhone.

The kicker is that Google Docs are only viewable from the iPhone. My initial hopes of editing a spreadsheet directly from the phone were quashed rudely in a live demo with the wife. Plan B is to use Google Doc’s forms to add individual expenses. This is really a better solution as it’s much easier for my wife to fill out three text fields than to worry about editing a spreadsheet in the right cells.

So the expense sheet of the document is simply the form entries: description, amount, and type. I added help text that listed the valid values I was looking for: food, gas, tickets, junk.

The budget sheet has four rows; one for each budget type. One column has the budgeted amount, and another uses “SUMIF” to sum up all the expense entries if the type matches the budget category. I can then subtract these two to get how much of our budgeted money remains in that category.

I bookmarked the form url on the iPhone for my wife and she can fill it out repeatedly. I also bookmarked the actual spreadsheet. It’s unfortunate that the Google Doc forms don’t let you specify a “thank you” url instead of a thank you message. Anyway, I bookmarked the actual Google Document so we can check the budget remaining easily while out and about. It seems that the iPhone has some trouble changing sheets while viewing Google Documents, so I made the budget sheet the first and default page.

All in all it’s very simple and has a high wife approval factor. Plus, the whole thing took me less than 30 minutes to setup including several “customer approval testing” iterations. Spreadsheets with Google Docs are really fun. Adding in these forms is almost like rapid prototyping custom web apps.

Tags budget, Disney, expenses, finances, Google, iPhone, vacation | 1 comment