Testing

• A process by which we increase our confidence in an implementation by observing it's behavior
• Testing cam revel the presence of errors but not their absence

Levels of Abstraction in Functionality

• Idea
• Specification
• Implementation

Dangers

• Spurious Test Failures: passes when should not
• False Positives: fails when should not

Levels of Testing

Unit Testing

• Individual components tested in isolation
• UUT (unit under test)

Ways of Unit Testing

• Black Box: Testing based on specification (don't look at code)
• White Box: Testing based on the code structure

Integration Testing

• Modules tested in combination to check whether they interface correctly

Ways of Integration Testing

• Bottom Up: Start with basic modules
• Top Down: Start with larger modules (main, interfaces)

System Testing

• Verify that the system as a whole meets requirements

Ways of Unit Testing

• Alpha: Tested by developers before releasing
• Beta: Tested by a group of willing customers before general releasing
• Acceptance: End-customer receives product and gives feedback

TDD (Test Driven Development)

• Write tests first