Ruby Best Practices

Keeping Things Organized

Just like other code, test suites tend to grow in both size and complexity throughout the lifecycle of a project. The following techniques help keep things tidy and well factored, allowing your tests to continue to serve as a road map to your project.

Embedding Tests in Library Files

If you are working on a very small program or library, and you want to be able to run your tests while in development, but then require the code as part of another program later, there is a simple idiom that is useful for embedding your tests:

class Foo
  ...
end

if __FILE__ == $PROGRAM_NAME
  require "test/unit"

  class TestFoo < Test::Unit::TestCase
    #...
  end
end

Simply wrapping your tests in this if statement will allow running ruby foo.rb to execute your tests, while require "foo" will still work as expected without running the tests. This can be useful for sharing small programs with others, or for writing some tests while developing a small prototype of a larger application. However, once you start to produce more than a few test cases, be sure to break things back out into their normal directory structure. Giant files can be a bit unwieldy to deal with, and it is a bit awkward (even though it is possible) to treat your lib/ directory as if it were also your test suite.

Test Helpers

When you begin to chain together a large amount of test cases, you might find that you are repeating some information across them. Some of the most common things in this regard are require statements and ...