What Is Hamcrest - Library of Matchers?

Hamcrest is a framework for writing matcher objects allowing 'match' rules to be defined declaratively. There are a number of situations where matchers are invaluble, such as UI validation, or data filtering, but it is in the area of writing flexible tests that matchers are most commonly used. This tutorial shows you how to use Hamcrest for unit testing.

When writing tests it is sometimes difficult to get the balance right between overspecifying the test (and making it brittle to changes), and not specifying enough (making the test less valuable since it continues to pass even when the thing being tested is broken). Having a tool that allows you to pick out precisely the aspect under test and describe the values it should have, to a controlled level of precision, helps greatly in writing tests that are "just right". Such tests fail when the behaviour of the aspect under test deviates from the expected behaviour, yet continue to pass when minor, unrelated changes to the behaviour are made.

Hamcrest was originally written by Erich Gamma and Kent Beck.

Hamcrest Releases:

Hamcrest 1.3 - 12-Jul-2014
Hamcrest 1.2 - May 2009
Hamcrest 1.1 - Jun 2007
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For more information, see Hamcrest Website

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