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Unformatted text preview: Software Testing, Quality Assurance and Maintenance Winter 2010 Lecture 2 — January 6, 2010 Patrick Lam version 1 RIP Fault Model Recall that a fault is something that’s latent or hiding, while a failure is visible (e.g. EPIC FAIL). To get from a fault to a failure: 1. Fault must be reachable ; 2. Program state subsequent to reaching fault must be incorrect: infection ; and 3. Infected state must propagate to output to cause a visible failure. Applications of the RIP model: automatic generation of test data, mutation testing. Test cases Informally, a test case contains: • what you feed to software; and • what the software should output in response. Here are two definitions to help evaluate how hard it might be to create test cases. Definition 1 Observability is how easy it is to observe the system’s behaviour, e.g. its outputs, effects on the environment, hardware and software. Definition 2 Controlability is how easy it is to provide the system with needed inputs and to get the system into the right state. Anatomy of a Test Case Consider testing a cellphone from the “off” state: h on i 1 519 888 4567 h talk i h end i prefix values test case values verification values exit codes postfix values 1 Definition 3...
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This note was uploaded on 03/19/2010 for the course CS 447 taught by Professor Lam during the Winter '10 term at Waterloo.
- Winter '10