Approval Tests are an alternative to assertions. You’ll find them useful for testing objects with complex values (such as long strings), lots of properties, or collections of objects.

Blog posts:

• ApprovalTests for Powerful Assertions in Swift: How to Get Started
• How to Verify Objects (and Simplify TDD) using ApprovalTests.Swift
• How to Verify Arrays and See Simple, Clear Diffs using ApprovalTests.Swift

A bad piece of code you can use for refactoring exercises, originally created by David Tanzer. Can you add tests, and clean up the code?

Learn Test-Driven Development by following the steps in this exercise, originally created by Robert Martin.

Blog posts:

• Xcode TDD Kata: Practice with the Bowling Game
  

The Objective-C implementation of Hamcrest. It’s library of predefined matchers (which you can use in test assertions), and a framework for creating your own matchers.

Blog posts:

• Hamcrest: A Tool for Readable, Powerful Unit Tests
  
• How OCHamcrest’s “hasProperty” Can Make Your Tests Simpler
• What Benefits Are There in the New, Improved OCHamcrest?
• How to Make Your Own OCHamcrest Matcher for Powerful Asserts
  

A “Paint by Numbers” TDD exercise originally created by Jeff Langr. We have provided the tests for you, all disabled. Your job is to do the rest: make the tests pass, then make your code clean. Sample solutions are provided.

Code snippets to help you write test cases. Available to all new subscribers.

Apple’s template fills test suites with cruft. By contrast, these test suite templates are sleek. They contain a single failing test, nothing else.

Blog posts:

• Is Apple Stuffing Your Code with Pointless Cruft?
• Would You Like an Improved Swift Unit Testing Template?