279 lines
11 KiB
Ruby
279 lines
11 KiB
Ruby
require 'test/unit/testcase'
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require 'test/unit/autorunner'
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module Test # :nodoc:
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#
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# = Test::Unit - Ruby Unit Testing Framework
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#
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# == Introduction
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#
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# Unit testing is making waves all over the place, largely due to the
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# fact that it is a core practice of XP. While XP is great, unit testing
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# has been around for a long time and has always been a good idea. One
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# of the keys to good unit testing, though, is not just writing tests,
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# but having tests. What's the difference? Well, if you just _write_ a
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# test and throw it away, you have no guarantee that something won't
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# change later which breaks your code. If, on the other hand, you _have_
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# tests (obviously you have to write them first), and run them as often
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# as possible, you slowly build up a wall of things that cannot break
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# without you immediately knowing about it. This is when unit testing
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# hits its peak usefulness.
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#
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# Enter Test::Unit, a framework for unit testing in Ruby, helping you to
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# design, debug and evaluate your code by making it easy to write and
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# have tests for it.
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#
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#
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# == Notes
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#
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# Test::Unit has grown out of and superceded Lapidary.
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#
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#
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# == Feedback
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#
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# I like (and do my best to practice) XP, so I value early releases,
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# user feedback, and clean, simple, expressive code. There is always
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# room for improvement in everything I do, and Test::Unit is no
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# exception. Please, let me know what you think of Test::Unit as it
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# stands, and what you'd like to see expanded/changed/improved/etc. If
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# you find a bug, let me know ASAP; one good way to let me know what the
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# bug is is to submit a new test that catches it :-) Also, I'd love to
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# hear about any successes you have with Test::Unit, and any
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# documentation you might add will be greatly appreciated. My contact
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# info is below.
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#
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#
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# == Contact Information
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#
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# A lot of discussion happens about Ruby in general on the ruby-talk
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# mailing list (http://www.ruby-lang.org/en/ml.html), and you can ask
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# any questions you might have there. I monitor the list, as do many
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# other helpful Rubyists, and you're sure to get a quick answer. Of
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# course, you're also welcome to email me (Nathaniel Talbott) directly
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# at mailto:testunit@talbott.ws, and I'll do my best to help you out.
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#
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#
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# == Credits
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#
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# I'd like to thank...
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#
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# Matz, for a great language!
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#
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# Masaki Suketa, for his work on RubyUnit, which filled a vital need in
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# the Ruby world for a very long time. I'm also grateful for his help in
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# polishing Test::Unit and getting the RubyUnit compatibility layer
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# right. His graciousness in allowing Test::Unit to supercede RubyUnit
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# continues to be a challenge to me to be more willing to defer my own
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# rights.
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#
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# Ken McKinlay, for his interest and work on unit testing, and for his
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# willingness to dialog about it. He was also a great help in pointing
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# out some of the holes in the RubyUnit compatibility layer.
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#
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# Dave Thomas, for the original idea that led to the extremely simple
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# "require 'test/unit'", plus his code to improve it even more by
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# allowing the selection of tests from the command-line. Also, without
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# RDoc, the documentation for Test::Unit would stink a lot more than it
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# does now.
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#
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# Everyone who's helped out with bug reports, feature ideas,
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# encouragement to continue, etc. It's a real privilege to be a part of
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# the Ruby community.
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#
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# The guys at RoleModel Software, for putting up with me repeating, "But
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# this would be so much easier in Ruby!" whenever we're coding in Java.
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#
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# My Creator, for giving me life, and giving it more abundantly.
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#
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#
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# == License
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#
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# Test::Unit is copyright (c) 2000-2003 Nathaniel Talbott. It is free
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# software, and is distributed under the Ruby license. See the COPYING
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# file in the standard Ruby distribution for details.
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#
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#
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# == Warranty
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#
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# This software is provided "as is" and without any express or
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# implied warranties, including, without limitation, the implied
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# warranties of merchantibility and fitness for a particular
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# purpose.
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#
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#
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# == Author
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#
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# Nathaniel Talbott.
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# Copyright (c) 2000-2003, Nathaniel Talbott
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#
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# ----
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#
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# = Usage
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#
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# The general idea behind unit testing is that you write a _test_
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# _method_ that makes certain _assertions_ about your code, working
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# against a _test_ _fixture_. A bunch of these _test_ _methods_ are
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# bundled up into a _test_ _suite_ and can be run any time the
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# developer wants. The results of a run are gathered in a _test_
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# _result_ and displayed to the user through some UI. So, lets break
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# this down and see how Test::Unit provides each of these necessary
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# pieces.
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#
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#
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# == Assertions
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#
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# These are the heart of the framework. Think of an assertion as a
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# statement of expected outcome, i.e. "I assert that x should be equal
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# to y". If, when the assertion is executed, it turns out to be
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# correct, nothing happens, and life is good. If, on the other hand,
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# your assertion turns out to be false, an error is propagated with
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# pertinent information so that you can go back and make your
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# assertion succeed, and, once again, life is good. For an explanation
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# of the current assertions, see Test::Unit::Assertions.
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#
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#
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# == Test Method & Test Fixture
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#
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# Obviously, these assertions have to be called within a context that
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# knows about them and can do something meaningful with their
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# pass/fail value. Also, it's handy to collect a bunch of related
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# tests, each test represented by a method, into a common test class
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# that knows how to run them. The tests will be in a separate class
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# from the code they're testing for a couple of reasons. First of all,
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# it allows your code to stay uncluttered with test code, making it
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# easier to maintain. Second, it allows the tests to be stripped out
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# for deployment, since they're really there for you, the developer,
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# and your users don't need them. Third, and most importantly, it
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# allows you to set up a common test fixture for your tests to run
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# against.
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#
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# What's a test fixture? Well, tests do not live in a vacuum; rather,
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# they're run against the code they are testing. Often, a collection
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# of tests will run against a common set of data, also called a
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# fixture. If they're all bundled into the same test class, they can
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# all share the setting up and tearing down of that data, eliminating
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# unnecessary duplication and making it much easier to add related
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# tests.
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#
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# Test::Unit::TestCase wraps up a collection of test methods together
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# and allows you to easily set up and tear down the same test fixture
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# for each test. This is done by overriding #setup and/or #teardown,
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# which will be called before and after each test method that is
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# run. The TestCase also knows how to collect the results of your
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# assertions into a Test::Unit::TestResult, which can then be reported
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# back to you... but I'm getting ahead of myself. To write a test,
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# follow these steps:
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#
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# * Make sure Test::Unit is in your library path.
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# * require 'test/unit' in your test script.
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# * Create a class that subclasses Test::Unit::TestCase.
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# * Add a method that begins with "test" to your class.
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# * Make assertions in your test method.
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# * Optionally define #setup and/or #teardown to set up and/or tear
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# down your common test fixture.
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# * You can now run your test as you would any other Ruby
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# script... try it and see!
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#
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# A really simple test might look like this (#setup and #teardown are
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# commented out to indicate that they are completely optional):
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#
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# require 'test/unit'
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#
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# class TC_MyTest < Test::Unit::TestCase
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# # def setup
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# # end
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#
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# # def teardown
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# # end
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#
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# def test_fail
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# assert(false, 'Assertion was false.')
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# end
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# end
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#
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#
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# == Test Runners
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#
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# So, now you have this great test class, but you still need a way to
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# run it and view any failures that occur during the run. This is
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# where Test::Unit::UI::Console::TestRunner (and others, such as
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# Test::Unit::UI::GTK::TestRunner) comes into play. The console test
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# runner is automatically invoked for you if you require 'test/unit'
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# and simply run the file. To use another runner, or to manually
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# invoke a runner, simply call its run class method and pass in an
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# object that responds to the suite message with a
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# Test::Unit::TestSuite. This can be as simple as passing in your
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# TestCase class (which has a class suite method). It might look
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# something like this:
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#
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# require 'test/unit/ui/console/testrunner'
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# Test::Unit::UI::Console::TestRunner.run(TC_MyTest)
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#
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#
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# == Test Suite
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#
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# As more and more unit tests accumulate for a given project, it
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# becomes a real drag running them one at a time, and it also
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# introduces the potential to overlook a failing test because you
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# forget to run it. Suddenly it becomes very handy that the
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# TestRunners can take any object that returns a Test::Unit::TestSuite
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# in response to a suite method. The TestSuite can, in turn, contain
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# other TestSuites or individual tests (typically created by a
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# TestCase). In other words, you can easily wrap up a group of
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# TestCases and TestSuites like this:
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#
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# require 'test/unit/testsuite'
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# require 'tc_myfirsttests'
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# require 'tc_moretestsbyme'
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# require 'ts_anothersetoftests'
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#
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# class TS_MyTests
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# def self.suite
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# suite = Test::Unit::TestSuite.new
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# suite << TC_MyFirstTests.suite
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# suite << TC_MoreTestsByMe.suite
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# suite << TS_AnotherSetOfTests.suite
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# return suite
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# end
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# end
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# Test::Unit::UI::Console::TestRunner.run(TS_MyTests)
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#
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# Now, this is a bit cumbersome, so Test::Unit does a little bit more
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# for you, by wrapping these up automatically when you require
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# 'test/unit'. What does this mean? It means you could write the above
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# test case like this instead:
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#
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# require 'test/unit'
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# require 'tc_myfirsttests'
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# require 'tc_moretestsbyme'
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# require 'ts_anothersetoftests'
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#
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# Test::Unit is smart enough to find all the test cases existing in
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# the ObjectSpace and wrap them up into a suite for you. It then runs
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# the dynamic suite using the console TestRunner.
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#
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#
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# == Questions?
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#
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# I'd really like to get feedback from all levels of Ruby
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# practitioners about typos, grammatical errors, unclear statements,
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# missing points, etc., in this document (or any other).
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#
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module Unit
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def self.run=(flag)
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@run = flag
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end
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def self.run?
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@run ||= false
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end
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end
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end
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at_exit do
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unless $! || Test::Unit.run?
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exit Test::Unit::AutoRunner.run($0 != "-e" && $0)
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end
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end
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