What is Unit Testing?

[IQAndreas]

I hear a lot about Unit Testing both arguments for and against it’s overuse. But I can’t seem to find a good explanation of it.

Could someone explain in beginner friendly terms what unit testing is, and how it applies to AS3 development, such as what is exactly involved with it?

[SIZE=1]Sadly, Wikipedia is less than helpful…

@Wikipedia

In computer programming, unit testing is a method by which individual units of [URL=“http://en.wikipedia.org/wiki/Source_code”]source code are tested to determine if they are fit for use. A unit is the smallest testable part of an application. In [URL=“http://en.wikipedia.org/wiki/Procedural_programming”]procedural programming a unit may be an individual function or procedure. Unit tests are created by programmers or occasionally by white box testers.

Ideally, each test case is independent from the others: substitutes like [URL=“http://en.wikipedia.org/wiki/Method_stub”]method stubs, [URL=“http://en.wikipedia.org/wiki/Mock_object”]mock objects,[URL=“http://en.wikipedia.org/wiki/Unit_testing#cite_note-mocksarentstubs-0”][1] [URL=“http://en.wikipedia.org/wiki/Mock_object#Mocks_and_fakes”]fakes and [URL=“http://en.wikipedia.org/wiki/Test_harness”]test harnesses can be used to assist testing a module in isolation. Unit tests are typically written and run by [URL=“http://en.wikipedia.org/wiki/Software_developer”]software developers to ensure that code meets its design and behaves as intended. Its implementation can vary from being very manual (pencil and paper) to being formalized as part of [URL=“http://en.wikipedia.org/wiki/Build_automation”]build automation.

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