Unit Testing

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Unit Testing

• What, Why, When, Where, Who and How.

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What is Unit Testing?

• Also know as Box Testing.
• Testing bits or units of code without running
  the entire application.
• This could be a object, a collection of objects,
  a library of procedures or functions or any other
  unit of code that can be tested independent
  from the rest of the application.

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Why should I do Unit Testing?

• To avoid having to compile and run the entire
  application just to check a single function.
• This reduces the cycle time between writing code
  and testing it. The shorter this cycle the better
  able you are to test specific functionality.

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Why should I do Unit Testing?

• Allows stress testing of code that may not be
  feasible by running the application.
• Many applications are too complex to fully test
  in the development phase. Many multi-user
  applications are shipped to clients without
  testing the level of use that will happen at the
  at the client site.
• Unit testing allows you to stress test individual
  sections of code in ways that a single user
  cannot.

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Why should I do Unit Testing?

• Have users or testers with domain knowledge do
  testing of particular functionality before it is
  incorporated into the main code.
• In many cases even very good specifications are
  not enough to write completely accurate code. If
  you can identify individuals that have detailed
  knowledge of a certain functionality, then you
  can write unit tests that will allow them to test
  that functionality before the code in
  incorporated into the application.

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Why should I do Unit Testing?

• Automated testing.
• Adding tests to the framework as you write code
  allows you to quickly, and repeatedly test code.
• There are a number of frameworks for generating
  automated tests.

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What should I Unit Test?

• Test objects.
• Test connections.
• Test forms.
• Test anything you can think of.

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When should I do Unit Testing?
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When should I do Unit Testing?

• Before you start to write code!!
• As you write code!!
• Any other time you can!!

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When should I do Unit Testing?

• Think of tests as part of code development.
• Before you start to write code, think How am I
  going to prove that this code works?
• If you are doing unit testing correctly

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When should I do Unit Testing?

• Think of tests as part of code development.
• Before you start to write code, think How am I
  going to prove that this code works?
• If you are doing unit testing correctly
• YOU ARE WRITING MORE TEST CODE THAN UNIT CODE!
• (up to 3 times as much! )

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When should I do Unit Testing?

• As part of design.
• In major programming projects it is not uncommon
  to have the manager of the test team as part of
  the design effort.
• Their job there is to ask the question How can
  we test this?
• Just asking this question can have a major impact
  on the design.

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When should I do Unit Testing?

• As part of development.
• As you add functionality you should be adding
  tests.
• Testing should be part of your daily development
  process.
• Start with a test application or test framework.
  Get the new code working and tested there. Only
  when the new code passes unit tests should it be
  added to the main application.

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When should I do Unit Testing?

• As part of the build process.
• Most of the automated testing frameworks include
  a console mode as well as a GUI mode. In your
  build script you can add some unit testing that
  will check to see if the build fails the tests.

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When should I do Unit Testing?

• As part of testing.
• This may seem redundant, but frequently
  developers keep their tests to themselves and do
  not pass them on to the testers.
• The testing department should have access to the
  unit tests as these can help them track down the
  source of a problem that occurs their testing.

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When should I do Unit Testing?

• As part of deployment process.
• When an application is deployed in more than one
  piece (Database, Server, Client), then unit tests
  can be done to check to see if the parts fit
  together as part of the deployment. (Does the
  database schema match the schema used by the
  server? Does the client communicate to the server
  correctly?)

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When should I do Unit Testing?

• As part of install.
• You can add unit tests to the install process to
  check basic functionality. Test can include
• Communication with database.
• Communication with server.
• File and network rights.
• Operating system, memory, processor, etc.

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When should I do Unit Testing?

• As part of a support call.
• You can add basic unit tests into the application
  under the help menu (or as a hidden keystroke).
• This allows support personal to get the user to
  run specific tests to locate the point of failure.

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Where should I do Unit Testing?

• On Development systems.
• On Non-Development systems.
• On systems not connected to the network.
• On User systems.
• Anywhere else.

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Who should do unit testing?

• Developers.
• Testers.
• Domain experts.
• Users.

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When should I not Unit Test.

• Unit testing can give the impression of slowing
  development.
• In some organizations there is a lot of pressure
  to show progress, even buggy progress. Time spent
  writing tests can often be perceived as wasted
  effort it your code passes all the tests.
• Of course, finding bugs during development saves
  up to 10 times the effort finding bugs after the
  product has shipped. However, sometimes it is
  necessary just to get something out the door.

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When should I not Unit Test.

• There are two sayings to remember.

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When should I not Unit Test.

• There are two sayings to remember
• Anything worth doing is worth doing well.

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When should I not Unit Test.

• There are two sayings to remember
• Anything worth doing is worth doing well.
• BUT
• Anything that needs doing, needs doing badly.

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How should I do Unit testing?

• Test applications.
• The easiest way to test code is to write a
  separate applications that allows you to enter
  the inputs to the unit your testing and see the
  outputs right away. This is ideal in situations
  where you want someone else to do the testing
  (someone who has particular knowledge of the
  required behaviour).

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How should I do Unit testing?

• Test output.
• In some cases there can be a large number of
  possible inputs and outputs that must be tested.
  You can use an myBase xml file to store a
  database of values to be tested and read the file
  into a client dataset, you can then output to a
  xml file or other text file and use a file
  compare utility to test for changes in the
  output. This is very handy for refactoring as you
  can easily compare before and after outputs.

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How should I do Unit testing?

• Automated testing.
• There are a number of automated testing frame
  works available. The most popular for Delphi is
  dUnit.

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Automated testing.

• A collection of tests (Test Suites).
• Based on a Boolean test.
• Separate application or part of application.
• At least 3 frameworks for Delphi. (Dunit, Qtest,
  Bubelen)
• Other frame works for Java, Small talk, C etc.

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Dunit What is it?

• Automated unit testing frame work.
• SourceForge project.
• Public domain.
• Full Source available.
• Runs in GUI and Console mode.
• Wide range of tests.
• Test extensions.

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QTest

• Alternate framework.
• From BigAtticHouse (http//www.bigattichouse.com/
  qtest.php)

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Bubelen

• From the Indy project
• (http//www.projectindy.org/bubelen/)