Program Testing

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Program Testing

• Eileen Landa
• York Region District School Board

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Purpose

• To look at why testing is so important
• To look at current industry thinking about
  programming and testing
• To look at methods to improve student ability to
  test
• To look at a specific testing option available
  for Java programming

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Agenda

• Extreme Programming
• Black box vs white box testing Industry
  standards
• Ministry expectations on testing
• Making testing fun (numtowords example)
• Tools for testing
• BlueJ individual class testing
• BlueJ unit testing record and capture

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Extreme Programming

• A deliberate and disciplined approach to software
  development
• Stress is on customer satisfaction
• Emphasizes team work
• Improves a software project in
• Communication
• Simplicity
• Feedback
• Courage
• Like a jigsaw puzzle

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A Change in the Way We Program

• Software engineered to be simple and elegant
• Savings in programmer costs outweigh savings in
  hardware cost by factor of at least 10 times
• XP emphasizes not just testing but testing well
• XP programmers do not mind changing requirements

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Rules and Practises

• Four phases
• Planning
• Designing
• Coding
• Testing

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Planning

• User stories written
• Release planning creates schedule
• Frequent small releases
• Project velocity is measured
• Project divided into iterations
• Iteration planning starts each iteration
• People move around
• Stand-up meeting starts each day
• Fix XP when it breaks

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Designing

• Simplicity
• System metaphor
• Use CRC cards
• Create spike solutions
• No functionality is added early
• Refactor

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Coding

• Customer always available
• Code must meet agreed standards
• Code unit test first
• All code is pair programmed
• One pair integrates code at a time
• Integrate often
• Collective code ownership
• Optimize last
• NO OVERTIME

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Testing

• All code has unit tests
• All tests must pass before release
• New bugs generate new tests
• Acceptance tests run often and scores published
• For more information check out
• www.extremeprogramming.org

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White Box Testing

• Explicit knowledge of code is required
• Every line of code is tested
• Every path through every if is executed
• Done by programmer who wrote the code

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Black Box Testing

• Internal workings of code is UNKNOWN to tester
• Tester knows what valid input is and what is
  expected to be done to the input
• Tester doesnt care how it is done
• Tester NEVER looks at the code
• Cont.

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Black Box Testing cont

• Advantages
• Test is unbiased
• Tester doesnt need knowledge of language used to
  program
• Viewpoint is that of user, not designer
• Test cases can be written as soon as
  specifications are complete
• Cont.

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Black Box Testing Cont.

• Disadvantages
• Some redundancy
• Test cases are difficult to design
• Testing all program paths not possible

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Black Box vs White Box Testing

• Both are needed to ensure working code
• In keeping with XP philosophy
• Write test case before writing code
• All tests must pass for integration

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Ministry Expectations on TestingProgramming
Stream

• TIK2O TFV.01, TFI.02, TFI.03, TF3.05, SPV.01,
  SPV.03, SP1.05, SP3.10, SP3.11, ICV.03
• ICS3M TFV.02, TF1.01, TF1.03, TF1.05, TF2.10,
  SPV.01, SP1.04, SP1.05, SP1.08, SP2.12, SP2.13,
  SP2.14, SP2.15, ICV.03
• ICS4M TFV.01, TF1.01, TF1.02, TF1.06, SPV.01,
  SPV.02, SPV.05, SP1.01, SP1.07, SP1.08, SP2.10,
  SP2.13, IC3.01

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Ministry Expectations on Testing Engineering
Stream

• TEE2O SPV.04, SP3.03
• ICE3M TFV.05, SP2.02, SP3.01, SP3.02
• ICE3E SPV.01, SP1.04, SP1.05, SP1.09, SP2.04,
  SP2.05, SP2.06
• ICE4M SPV.05, SP2.04, SP3.02
• ICE4E TF2.04, SPV.03, SP1.05, SP1.06, SP1.07,
  SP1.08, SP1.09, SP1.10, SP1.11, SP1.17

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Making Testing Fun

• Students love to find errors with our work
• Provide them with programs that intentionally do
  not work
• Let them
• Find the errors
• Fix the errors

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Example

• Program is written to convert valid integers (-32
  768 to 32 767) into words
• Eg -25 -gt negative twenty-five
• Eg 372 -gt three hundred and seventy- two

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Test Plan
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Test the Program

• On computer, double click the program
• NUMWORD.EXE

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The Program Screen
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Continuing

• Give them the source
• Have them fix the errors
• They also fix their test plan errors
• gt 80 of programming is in maintenance/repair mode

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Errors

• Did you find any errors?
• Was your test plan complete?
• What was missing from your plan?

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Tools for Testing

• Some IDEs have tools built in
• BlueJ has 2 particularly useful testing features
• Individual Class Testing
• Unit Testing Record and Capture

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BlueJ Individual Class Testing

• BlueJ has a workbench
• Can add instances of any class
• Can run any class methods
• Can inspect the variables

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The Diary Project

• A simple project that will allow us to book
  appointments during a weekday of 9-5.
• Appointments must be multiples of one hour in
  length
• Appointments must start on the hour

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BlueJ

• Open BlueJ
• Open the project diary-prototype
• 3 classes week, day, appointment
• Right click on a class to create an instance

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The BlueJ Screen
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The Inspect Window
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Tasks

• Create several appointment objects, some of
  length 1 and 2 hours
• Create a day object
• Try to book appointments at 900 am, 100 pm and
  500 pm
• Try to book a second appointment at 900 am
• Try some other tests

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The Method Result
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Inspecting

• Lets inspect the day object
• Right click on day instance and choose inspect

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Following the Arrows cont

• Click on an appointment

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Following the Arrows

• Click on the appointment arrow and click inspect

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BlueJ Unit Testing Record and Capture

• Predefine a test condition
• Record tests
• Can rerun them at any time
• Tools -gt preferences -gt miscellaneous -gt show
  testing tools

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Creating a TestCase

• Right click on appointment class
• Create test class
• Right click on test class
• Object bench to test fixture
• Right click on test class
• Create test method
• Give name
• Run Test
• End

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Try This

• Right click on Test Appointment class
• Test Fixture to Object Bench
• Create Test Day class
• Right click on Test Day class
• Object Bench to Test Fixture

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Try This cont

• Create Day Test method named AddDuplicate
• Add an appointment for 9
• Assert that result is false
• End
• Run the tests

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Try This cont

• Create Day Test method named AddNew
• Add an appointment for 10
• Assert that result is false
• End
• Run the tests

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Results

• Notice that the AddNew test failed.
• Why??

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Adding Tests Manually

• Open Editor on Day Test class
• Observe the methods
• Setup creates the Object Bench
• Each Test has its own method
• Fix the TestNew method to assert True
• Try the tests again

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Explore

• There are several projects available to you to
  try out
• Inspect them
• Fix them
• Enjoy them

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Recap

• Testing philosophies
• Function Testing
• Unit Testing
• BlueJ

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Resources

• Extreme Programming
• www.extremeprogramming.org
• BlueJ
• www.bluej.org
• Karel the Robot
• www.learningwithrobots.com
• My email
• Eileen.Landa_at_yrdsb.edu.on.ca