h1. Testing

Untested code is broken code, so we take testing seriously.  Off the bat you get to use either JUnit or TestNG for writing unit tests and integration tests. And you can also add your own framework, or even script tests using Ruby.  But= first, let's start with the basics.


h2. Writing Tests

Each project has a @TestTask@ that you can access using the @test@ method. @TestTask@ reflects on the fact that each project has one task responsible for getting the tests to run and acting on the results.  But in fact there are several tasks that do all the work, and a @test@ task coordinates all of that.

The first two tasks to execute are @test.compile@ and @test.resources@.  They work similar to @compile@ and @resources@, but uses a different set of directories.  For example, Java tests compile from the @src/test/java@ directory into the @target/test/classes@ directory, while resources are copied from @src/test/resources@ into @target/test/resources@.

The @test.compile@ task will run the @compile@ task first, then use the same dependencies to compile the test classes.  That much you already assumed.  It also adds the test framework (e.g. JUnit, TestNG) and JMock to the dependency list.  Less work for you.

If you need more dependencies, the best way to add them is by calling @test.with@.  This method adds dependencies to both @compile.dependencies@ (for compiling) and @test.dependencies@ (for running).  You can manage these two dependency lists separately, but using @test.with@ is good enough in more cases.

Once compiled, the @test@ task runs all the tests.

Different languages use different test frameworks.  You can find out more about available test frameworks in the "Languages":languages.html section.


h2. Excluding Tests and Ignoring Failures

If you have a lot of tests that are failing or just hanging there collecting dusts, you can tell Buildr to ignore them.  You can either tell Buildr to only run specific tests, for example:

{{{!ruby
test.include 'com.acme.tests.passing.*'
}}}

Or tell it to exclude specific tests, for example:

{{{!ruby
test.exclude '*FailingTest', '*FailingWorseTest'
}}}

Note that we're always using the package qualified class name, and you can use star (@*@) to substitute for any set of characters.

When tests fail, Buildr fails the @test@ task.  This is usually a good thing, but you can also tell Buildr to ignore failures by resetting the @:fail_on_failure@ option:

{{{!ruby
test.using :fail_on_failure=>false
}}}

Besides giving you a free pass to ignore failures, you can use it for other causes, for example, to be somewhat forgiving:

{{{!ruby
test do
  fail 'More than 3 tests failed!' if test.failed_tests.size > 3
end
}}}

The @failed_tests@ collection holds the names of all classes with failed tests. And there's @classes@, which holds the names of all test classes.  Ruby arithmetic allows you to get the name of all passed test classes with a simple @test.classes – test.failed_tests@.  We'll let you imagine creative use for these two.


h2. Running Tests

It's a good idea to run tests every time you change the source code, so we wired the @build@ task to run the @test@ task at the end of the build.  And conveniently enough, the @build@ task is the default task, so another way to build changes in your code and run your tests:

{{{!sh
$ buildr
}}}

That only works with the local @build@ task and any local task that depends on it, like @package@, @install@ and @upload@.  Each project also has its own @build@ task that does not invoke the @test@ task, so @buildr build@ will run the tests cases, but @buildr foo:build@ will not.

While it's a good idea to always run your tests, it's not always possible. There are two ways you can get @build@ to not run the @test@ task.  You can set the environment variable @test@ to @no@ (but @skip@ and @off@ will also work). You can do that when running Buildr:

{{{!sh
$ buildr test=no
}}}

Or set it once in your environment:

{{{!sh
$ export TEST=no
$ buildr
}}}

If you're feeling really adventurous, you can also disable tests from your Buildfile or @buildr.rb@ file, by setting @options.test = false@. We didn't say it's a good idea, we're just giving you the option.

The @test@ task is just smart enough to run all the tests it finds, but will accept include/exclude patterns.  Often enough you're only working on one broken test and you only want to run that one test.  Better than changing your Buildfile, you can run the @test@ task with a pattern.  For example:

{{{!sh
$ buildr test:KillerAppTest
}}}

Buildr will then run only tests that match the pattern @KillerAppTest@.  It uses pattern matching, so @test:Foo@ will run @com.acme.FooTest@ and @com.acme.FooBarTest@.  With Java, you can use this to pick a class name, or a package name to run all tests in that package, or any such combination.  In fact, you can specify several patterns separated with commas.  For example:

{{{!sh
$ buildr test:FooTest,BarTest
}}}

As you probably noticed, Buildr will stop your build at the first test that fails.  We think it's a good idea, except when it's not.  If you're using a continuous build system, you'll want a report of all the failed tests without stopping at the first failure.  To make that happen, set the environment variable @test@ to "all", or the Buildr @options.test@ option to @:all@.  For example:

{{{!sh
$ buildr package test=all
}}}

We're using @package@ and not @build@ above.  When using a continuous build system, you want to make sure that packages are created, contain the right files, and also run the integration tests.


h2. Integration Tests

So far we talked about unit tests.  Unit tests are run in isolation on the specific project they test, in an isolated environment, generally with minimal setup and teardown.  You get a sense of that when we told you tests run after the @build@ task, and include JMock in the dependency list.

In contrast, integration tests are run with a number of components, in an environment that resembles production, often with more complicates setup and teardown procedures.  In this section we'll talk about the differences between running unit and integration tests.

You write integration tests much the same way as you write unit tests, using @test.compile@ and @test.resources@.  However, you need to tell Buildr that your tests will execute during integration test.  To do so, add the following line in your project definition:

{{{!ruby
test.using :integration
}}}

Typically you'll use unit tests in projects that create internal modules, such as JARs, and integration tests in projects that create components, such as WARs and EARs.  You only need to use the @:integration@ option with the later.

To run integration tests on the current project:

{{{!sh
$ buildr integration
}}}

You can also run specific tests cases, for example:

{{{!sh
$ buildr integration:ClientTest
}}}

If you run the @package@ task (or any task that depends on it, like @install@ and @upload@), Buildr will first run the @build@ task and all its unit tests, and then create the packages and run the integration tests.  That gives you full coverage for your tests and ready to release packages.  As with unit tests, you can set the environment variable @test@ to "no" to skip integration tests, or "all" to ignore failures.


h2. Using Setup and Teardown

Some tests need you to setup an environment before they run, and tear it down afterwards.  The test frameworks (JUnit, TestNG) allow you to do that for each test.  Buildr provides two additional mechanisms for dealing with more complicated setup and teardown procedures.

Integration tests run a setup task before the tests, and a teardown task afterwards.  You can use this task to setup a Web server for testing your Web components, or a database server for testing persistence.  You can access either task by calling @integration.setup@ and @integration.teardown@.  For example:

{{{!ruby
integration.setup { server.start ; server.deploy }
integration.teardown { server.stop }
}}}

Depending on your build, you may want to enhance the setup/teardown tasks from within a project, for example, to populate the database with data used by that project's test, or from outside the project definition, for example, to start and stop the Web server.

Likewise, each project has its own setup and teardown tasks that are run before and after tests for that specific project.  You can access these tasks using @test.setup@ and @test.teardown@.


h2. Testing Your Build

So you got the build running and all the tests pass, binaries are shipping when you find out some glaring omissions.  The license file is empty, the localized messages for Japanese are missing, the CSS files are not where you expect them to be.  The fact is, some errors slip by unit and integration tests.  So how do we make sure the same mistake doesn't happen again?

Each project has a @check@ task that runs just after packaging.  You can use this task to verify that your build created the files you wanted it to create. And to make it extremely convenient, we introduced the notion of expectations.

You use the @check@ method to express and expectation.  Buildr will then run all these expectations against your project, and fail at the first expectation that doesn't match.  An expectation says three things.  Let's look at a few examples:

{{{!ruby
check package(:war), 'should exist' do
  it.should exist
end
check package(:war), 'should contain a manifest' do
  it.should contain('META-INF/MANIFEST.MF')
end
check package(:war).path('WEB-INF'), 'should contain files' do
  it.should_not be_empty
end
check package(:war).path('WEB-INF/classes'), 'should contain classes' do 
  it.should contain('**/*.class')
end
check package(:war).entry('META-INF/MANIFEST'), 'should have license' do
  it.should contain(/Copyright (C) 2007/)
end
check file('target/classes'), 'should contain class files' do
  it.should contain('**/*.class')
end
check file('target/classes/killerapp/Code.class'), 'should exist' do
  it.should exist
end
}}}

The first argument is the subject, or the project if you skip the first argument.  The second argument is the description, optional, but we recommend using it.  The method @it@ returns the subject.

You can also write the first expectation like this:

{{{!ruby
check do
  package(:jar).should exist
end
}}}

We recommend using the subject and description, they make your build easier to read and maintain, and produce better error messages.

There are two methods you can call on just about any object, called @should@ and @should_not@.  Each method takes an argument, a matcher, and executes that matcher.  If the matcher returns false, @should@ fails.  You can figure out what @should_not@ does in the same case.

Buildr provides the following matchers:

|_. Method |_. Checks that ... |
| @exist@   | Given a file task checks that the file (or directory) exists. |
| @empty@   | Given a file task checks that the file (or directory) is empty. |
| @contain@ | Given a file task referencing a file, checks its contents, using string or regular expression.  For a file task referencing a directory, checks that it contains the specified files; global patterns using @*@ and @**@ are allowed. |

All these matchers operate against a file task.  If you run them against a ZipTask (including JAR, WAR, etc) they can also check the contents of the ZIP file.  And as you can see in the examples above, you can also run them against a path in a ZIP file, checking its contents as if it was a directory, or against an entry in a ZIP file, checking the content of that file.

p(note). The @package@ method returns a package task based on packaging type, identifier, group, version and classifier.  The last four are inferred, but if you create a package with different specifications (for example, you specify a classifier) your checks must call @package@ with the same qualifying arguments to return the very same package task.

Buildr expectations are based on RSpec.  "RSpec":http://rspec.info/ is the behavior-driven development framework we use to test Buildr itself.  Check the RSpec documentation if want to see all the supported matchers, or want to write your own.


h2. Behaviour-Driven Development

Buildr supports several Behaviour-Driven Development(BDD) frameworks for testing your projects.  Buildr follows each framework naming conventions, searching for files under the @src/spec/{lang}@ directory.

You can learn more about each BDD framework in the "Languages":languages.html section.


Next, let's talk about "customizing your environment and using profiles":settings_profiles.html