console

> ruby -rmath_functions.rb -e "puts MathFunctions.factorial(2)"
2
 
> ruby --test -rmath_functions.rb
 
.
 
Finished in 1.000706 seconds.
 
1 tests, 2 assertions, 0 failures, 0 errors

math_functions.rb

module MathFunctions
  def self.factorial(n)
    (1..n).inject(1) { |acc, x| acc * x}
  end
end

=begin :unittest

assert MathFunctions.factorial(6) == 720
assert MathFunctions.factorial(5) == 120

=end

Hi Foy,

I just heard you mention inline testing in a podcast. I've been thinking about this as well and had a more complex solution. Yours looks interesting, but it doesn't work on my command line. Apparently the --test flag isn't know, what ruby version are you using? I'm assuming that this is not a fictive example, or is it?

Jeroen

Alas, you're right: this gist is total fiction, and we were really just starting to consider the potential syntax and semantics for inline unit tests.

My goals here were to:

1. have something similar to D unit tests ( http://www.digitalmars.com/d/2.0/unittest.html )
2. maintain backward compatibility at no cost when it came to interpreting the code

I'm starting to think however that this may be a bit short-sighted and that pushing for a 'conditional interpretation' keyword similar to D's 'version' ( http://www.digitalmars.com/d/2.0/version.html ) might be the right choice since it'd not only read better but serve wider purposes.

Out of interest, what was your complex solution?

Very Interesting.

I was thinking about inline tests with the following goals in mind:

• no need to worry anymore where to put your test, no need to switch to a separate file, just put it above the (method, class or module) definition
• reuse the tests as example code

So I was thinking to add the test between the normal documentation for a method/module/class. I have currently focused on methods only.

The solution I have come up with is based on the Module#method_added hook method. I need to work it out further to give you a good example, but here is some code I extracted from the code I'm working on http://gist.github.com/388532#file_inline_test.feature . This doesn't work, but I hope it gives you an idea. I do have something simple (like the feature example) working locally.

What do you think of this approach?

FYI, I have restructured stuff and started writing a simple gem and added some examples using rspec.

Not sure how this will end up. Here is the repo http://github.com/jeroenvandijk/inline_tests