This document provides an overview of unit testing and guidelines for writing unit tests. It discusses why unit tests are important for catching errors, helping write code, speeding up development, and covering configurations and new team members' code. It defines what a unit test is and what they don't cover. Guidelines provided include automating tests, letting code just pass tests, testing boundaries and randomness, keeping tests at a unit level, and knowing passed tests don't guarantee correctness. It also mentions the XCTest framework and provides a tutorial project and instructions for writing sample unit tests for email and password validation.

1. Unit Testing
Brian Hu

2. Why Test
• Catch errors
• Help you write code
• Speed up your development
• Cover configurations
• Cover new co-workers

3. What is a unit test
• Tests ONE thing
• Single “unit” of functionality
• Small, fast, ISOLATED

4. Unit Tests don’t cover
• Performance
• UI interaction
• Whole system integration

5. Guidelines
• Testing should be automated and non-interactive
• Let your code JUST pass the test
• Remember to test boundary cases, but also remember that it’s
impossible to test every case
• Provide a random generator when it’s possible
• Keep testing at unit level
• Act as 3rd party class consumer
• Passed tests don’t promise the correctness of code

6. XCTest

7. Tutorial Project
http://is.gd/nDMTWU

8. Instruction
• We have 4 tests in this project: testValidateEmail,
testSubmit, testIsEmpty, testValidatePassword
• I’ll do the “testValidateEmail” step by step for you.
• I have written the tests of “testIsEmpty” and
“testSubmit” for you. Please implement the logic
by yourself.
• Please write the test and implement the logic for
the last test by yourself.

9. API you may need
#if DEBUG
[NSException raise:@“Invalid Email Exception”
format:@"email is invalid”];
#endif

10. Password requirement
• length between 6~12
• has at least 1 uppercase letter and 1 lowercase
letter