Introduction Testing in the beginning of a malady

Introduction

Testing �" in the beginning of a malady it is easy to cure but difficult to detect, but in the course of time, not having been either detected or treated in the beginning, it becomes easy to detect but difficult to cure. " Nicolo Machiavelli The Prince, 1513

Program Behaviour Specification Program Extra Functionality Missing Functionality Correct Portion

Correctness �Impossible to demonstrate �Better viewpoint �Program P is correct with respect to specification S �Do the specification and the program meet the customer/user’s expectations? �Test cannot never reveal the absence of a fault

Testing Program Behaviour Specification Program Test Cases

Test Cases �Test method is a repeatable way to generate test cases

Basic Approaches �Black Box (Functional Testing) �White Box (Structural Testing) �Grey Box

Content of a Test Case �“Boilerplate”: author, date, propose (summary), test case ID, reference to specification, version �Pre-conditions (including environment) � Inputs �Expected Outputs �Observed Outputs �Pass/Fail

Testing Levels �Acceptance Testing – assess software with respect to requirements �System Testing – assess software with respect to architecture design �Integration Testing – assess software with respect to subsystem design �Module Testing – assess software with respect to detail design �Unit Testing – assess software with respect to implementation

Vocabulary �Error – People make errors �Fault – A fault is the result of an error �Failure – A failure occurs when a fault executes �Incident – is the symptom associated with a failure that alerts the user to the occurrence of a failure