Here's a few links to help with unit testing on iOS...

Tools

• Specta
• Expecta
• OCMockito
• Cedar
• OCMock

Blogs

• Real-World Testing with XCTest
• Test-Driven iOS Development with Specta and Expecta
• TDD With Specta and Expecta
• Setting up an in-memory Core Data stack for unit testing
• Testing Core Data with OCMock
• OCMock Test Origami
• Why I prefer testing with Specta, Expecta, and OCMockito
• Test Doubles: Mocks, Stubs, and More