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Testing Policy• Only exhaustive testing can show a program is
free from defects. However, exhaustive testing is impossible;
• Testing policies define the approach to be used in selecting system tests; For example,– All functions accessed through menus should
be tested;– Combinations of functions accessed through the
same menu should be tested;– Where user input is required, all functions must
be tested with correct and incorrect input.
Requirements System testing
Architectural Integration Design Testing
Detail Unit Design Testing
Implementation
Software Testing & Development Life Cycle
moduleto betested
Software Engineer
Result
Test Cases
Unit Testing
moduleto betested
Test Cases
InterfaceLocal Data Structures
Unit Testing
Boundary ConditionsIndependent pathsError Handling Paths
DRIVER
MODULE
STUBSTUB
Test Cases
InterfaceLocal Data Structures
Boundary ConditionsIndependent pathsError Handling Paths
Result
Integration Testing Involves building a system from its components and testing it for problems that arise from component interactions.Top-down integration
Develop the skeleton of the system and populate it with components.
Bottom-up integrationIntegrate infrastructure components then add functional components.To simplify error localisation,
systems should be incrementally integrated.
Integration Testing
The Big-bang Approach.
Incremental Approach.
A Stub is a special code arrangement when called by any other module, stimulates the behaviour of an well designed and existing module which is not yet constructed or developed.
What is mean by
stub
Top-Down Integration
Top module is tested with
Stub
Stubs are all Replaced one at a time, Depth first
As new modules are integrated, some subset of tests is re-run
A
B
C
F G
D E
Bottom-Up Integration
A
B F G
Drivers are replaced one at a time, Depth First.
Worker modules are grouped into builds and Integrated
C
D ECluster
Thread-Based Integration
A
B F G
Top Modules are tested with stubs
Worker modules are grouped into builds and Integrated
C
D ECluster
Systems testing
One
• System Functional Test• Test entire system against the functional
requirements.
Two
• System Performance Test• Test the non-functional requirements of the system. For example,• System Performance Test
• Test the non-functional requirements of the system. For example,
Three
• System Acceptance Test• Set of tests that the software must pass before it is
accepted by the client.
Trivial example•You have been asked to write a term paper on ‘Integration Testing in Component Based System’. To do this, you need to find references from a range of library databases.1• You logs on to the KFUPM library system and uses the
search facility to find relevant papers from IEEE, ACM and Elsevier databases. 2
• One paper of special interest requires authentication and you have to fill an online form to receive the paper.• If you are allowed, the paper will be downloaded and
ready for collection.• An email will be send to you once the paper is ready.
3Scenario-based
Testing
Trivial Example-System TestingTest the login mechanism using correct and incorrect login.
Test the search facility using queries against known source to check that the search mechanism is actually documents.
Test system presentation facility to check that information about documents is displayed properly.
Test the mechanism to request permission for downloading.
Test the e-mail response indicating that the download document is available
Regression Testing Change do not always effect the entire
program.
After each change• Entire test suite of a system must be
run again.
Need for an automatic test suite execution.
Test activities
These steps generally remain same from
unit testing to system testing.
Coverage criterion;• Equivalence Partitioning• Boundary-Value Analysis• Coverage-Based Testing• Control-flow• Data-flow
Expected behavior of every test input to be
generated. (Test Oracles)
Testing environment.
Test Case selection
Test Oracles
Text Execution
Test inputs on the ‘program-under-test’
• Record the actual behavior.
Generally can be automated to an
extend !!!!
Test Evaluation
Compare the actual behavior with the expected behavior.
Generally can be automated to an
extend !!!!
Test Reporting
Report the outcome of the testing.• Developers• Project Mangers etc.
Generally can be automated to an
extend !!!!
Key points
Each type of testing is aimed at detecting different kinds of failures
Testing boils down to the selection and execution of test cases.
A system typically undergoes a range of testing types.
Created BySrivignesh
The ability to convert ideas to things is
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