Software Quality assurance

Quality assurance tests

• Debugging– process of finding out where something went

wrong and correcting the code to eliminate the errors and bugs that cause unexpected results

Types of errors

• Language error (syntax)

• Run time error

• logic error

Quality assurance testing

• Types– Error based testing

– Scenario based testing

Quality assurance testing

• Types• Error based testing

– Search a given class’s method for particular clues of interest, then describe how these clues should be tested

– Ex: employee.computepayroll(hour)

• Scenario based testing– Usage based testing– Concentrates on what users does, not on what

product does

Testing strategies

• Black box testing– Internal working is not available for inspection– Input and output tested

• White box testing– Test the specific logic to guarantee the system’s

proper functioning– Path testing

• one form of white box testing• Make sure the path of the method executed at least once

during testing• Two types

– statement testing coverage– Branch testing coverage

Testing strategies

• Top down testing– assumes that main logic or objects interactions and

systems messages of the application need more testing than individual objects methods or supporting logic

– Can detect serious design flaws early in the implementation

• Bottom up testing– To test individual objects– Starts with the details of the system and proceeds to

higher levels by a progressive aggregation

Impact of object orientation on testing

• Impact of inheritance in testing• Base class

– Inherited()– redefined()

• Derived class– Inherited()– redefined()

• Reusability of tests– In this inheritance example

• Ssets of test requirement ‘ll overlap.

Test plan

• Test plan is developed to detect and identify potential problems before delivering the software to its users

Steps to create test plan

• Objectives of the test– What

• Development of a test case

• how

• Test analysis– Examining test output, and documemntation

the test result

Who should do the testing

• Designers

• Quality assurance group

• Beta testing– popular– Expensive– Group of actual users of the system

• Alpha testing