Rdoctest

A doctest for Ruby.

Why?

You’ll improve your test coverage and documentation in one fell swoop.

How?

Install the gem:

% [sudo] gem install rdoctest

Use the CLI:

% rdoctest lib/**/*.rb
Loaded suite /.../bin/rdoctest
Started
.
Finished in ... seconds.

1 tests, 6 assertions, 0 failures, 0 errors, 0 skips

Examples

Formatting

Rdoctest expects well-formatted RDoc. This means:

Indent examples by 2 spaces.

# For example:
#
#   1 + 1 # This code is indented by 2 spaces.

If your example is a block of code, use # => to designate the expected result.

# Short blocks can have the result on the same line:
#
#   1 + 1 # => 2
#
# Longer blocks can have the result on the line following:
#
#   def hello_world
#     puts "Hello, world!"
#   end
#   # => nil

If your example is an IRB session, use >> and => accordingly.

# Simple:
#
#   >> 1 + 1
#   => 2
#
# More complex, testing output:
#
#   >> def hello_world
#   >>   puts "Hello, world!"
#   >> end
#   => nil
#   >> hello_world
#   Hello, world!
#   => nil
#
# Use ellipses for partial matches:
#
#   >> goodbye_world
#   NameError: undefined local variable or method `goodbye_world'...

CLI

Rdoctest’s CLI works a lot like Ruby’s.

% rdoctest -h
Usage: rdoctest [options] [file ...]
    -Idirectory
    -rlibrary
    -f                               Don't automatically require files
    ...

If you’re testing a complex project, make sure you prepare necessary libraries and load paths:

% rdoctest -Ilib -rmylibrary lib/**/*.rb

If your application handles the loading of files, suppress Rdoctest’s autoload mechanism:

$ rdoctest -f -r./config/environment app/**/*.rb

Rake

Rdoctest comes with a Rake task that you can load in your Rakefile.

require 'rdoctest/task'
Rdoctest::Task.new

Running it is simple.

% rake doctest

It implements a configuration similar to Rake’s TestTask.

Rdoctest::Task.new :test do |t|
  t.libs      << 'lib'          # The 'lib' directory is loaded by default,
  t.ruby_opts << '-rrdoctest'   # but require needed files with +ruby_opts+.
end

Rails

I haven’t done much testing in Rails yet, but the following should work:

First, update your Gemfile to include the gem in your test group.

group :test do
  gem 'rdoctest'
end

Run bundle install, and you can immediately invoke the CLI.

% rdoctest -f -r./config/environment app/**/*.rb lib/**/*.rb

Roadmap

Better detection of code blocks (the 2-space indent is too restrictive).
Test plain text files (READMEs, for example).
Autotest integration?
Better Rails support?
Test shell snippets (beginning with $ and %)?

Prior Art

rubydoctest

License

(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.