You can write a small Ruby library in only a few lines. But then it grows, it expands and then it starts to break and become a maintenance nightmare. Since its open source you just stop working on it. Users complain that the project has been abandoned. Your project ends up causing more grief for everyone than if you'd never written it at all. Instead, we will learn to write all Ruby libraries, RubyGems with tests. This session is NOT about "how to do TDD". More importantly this session will teach you: * the one command you should run before starting any new Ruby project * the best way to write tests for command-line apps, Rake tasks and other difficult to test code * how to do Continuous Integration of your Ruby/Rails libraries with runcoderun.com Once you know how to write tests for all Ruby code, you'll want to do it for even the smallest little libraries and have the confidence to know your code always works.

1. How to write tests/
stories for RubyGems
Dr Nic Williams
mocra.com
drnicwilliams.com
@drnic
$ sudo gem install tweettail
$ tweettail jaoo -f

2. JAOO.au loves Ruby

3. http://www.slideshare.com/drnic

5. tweettail
$ sudo gem install tweettail
$ tweettail jaoo
mattnhodges: Come speak with me at JAOO next week - http://jaoo.dk/
Steve_Hayes: @VenessaP I think they went out for noodles. #jaoo
theRMK: Come speak with Matt at JAOO next week
drnic: reading my own abstract for JAOO presentation

6. New Gem in 2min
newgem tweet-tail
cd tweet-tail
script/generate executable tweettail
rake manifest
rake install_gem

7. Rakefile
$hoe = Hoe.new('tweettail', TweetTail::VERSION) do |p|
p.developer('FIXME full name', 'FIXME email')
...
end
$hoe = Hoe.new('tweettail', TweetTail::VERSION) do |p|
p.developer('Dr Nic', 'drnicwilliams@gmail.com')
...
end

8. README.rdoc
= tweet-tail
* FIX (url)
= tweet-tail
* http://github.com/drnic/tweet-tail

9. New Gem in 2min
cont...
newgem tweet-tail
cd tweet-tail
script/generate executable tweettail
rake manifest
rake install_gem
tweettail
SUCCESS!! To update this executable,
look in lib/tweet-tail/cli.rb

10. User story
Feature: Live twitter search results
on the command line
In order to reduce cost of getting
live search results
As a twitter user
I want twitter search results
appearing in the console

11. Describe behaviour in plain text
Write a step definition in Ruby
Run and watch it fail
Fix code
Run and watch it pass!

12. Install cucumber
sudo gem install cucumber
script/generate install_cucumber
cp story_text features/command_line_app.feature

13. features/cli.feature
Feature: Live twitter search results on command line
In order to reduce cost of getting live search results
As a twitter user
I want twitter search results appearing in the console
Scenario: Display current search results
Given twitter has some search results for 'jaoo'
When I run local executable 'tweettail' with arguments 'jaoo'
Then I should see
quot;quot;quot;
mattnhodges: Come speak with me at JAOO next week...
Steve_Hayes: @VenessaP I think they went out for...
theRMK: Come speak with Matt at JAOO next week...
drnic: reading my own abstract for JAOO presentation...
quot;quot;quot;

14. Running scenario
$ cucumber features/command_line_app.feature
...
1 scenario
2 skipped steps
1 undefined step
You can implement step definitions for missing steps
with these snippets:
Given /^twitter has some search results for quot;([^quot;]*)quot;$/ do |arg1|
pending
end

15. features/step_definitions/
twitter_data_steps.rb
Given /^twitter has some search results for quot;([^quot;]*)quot;$/ do |query|
FakeWeb.register_uri(
:get,
quot;http://search.twitter.com/search.json?q=#{query}quot;,
:file => File.dirname(__FILE__) +
quot;/../fixtures/search-#{query}.jsonquot;)
end

16. features/step_definitions/
twitter_data_steps.rb
mkdir -p features/fixtures
curl http://search.twitter.com/search.json?q=jaoo >
features/fixtures/search-jaoo.json

17. features/fixtures/search-jaoo.rb
{
quot;resultsquot;: [
{
quot;textquot;: quot;reading my own abstract for JAOO presentationquot;,
quot;from_userquot;: quot;drnicquot;,
quot;idquot;: 1666627310
},
{
quot;textquot;: quot;Come speak with Matt at JAOO next weekquot;,
quot;from_userquot;: quot;theRMKquot;,
quot;idquot;: 1666334207
},
{
quot;textquot;: quot;@VenessaP I think they went out for noodles. #jaooquot;,
quot;from_userquot;: quot;Steve_Hayesquot;,
quot;idquot;: 1666166639
},
{
quot;textquot;: quot;Come speak with me at JAOO next week - http://jaoo.dk/quot;,
quot;from_userquot;: quot;mattnhodgesquot;,
quot;idquot;: 1664823944,
}],
quot;refresh_urlquot;: quot;?since_id=1682666650&q=jaooquot;,
quot;results_per_pagequot;: 15,
quot;next_pagequot;: quot;?page=2&max_id=1682666650&q=jaooquot;

18. features/common/env.rb
gem quot;fakewebquot;
require quot;fakewebquot;
Before do
FakeWeb.allow_net_connect = false
end

19. Running scenario
$ cucumber features/command_line_app.feature
...
Scenario: Display current search results
Given a safe folder
And twitter has some search results for quot;jaooquot;
When I run local executable quot;tweettailquot; with arguments quot;jaooquot;
Then I should see
quot;quot;quot;
mattnhodges: Come speak with me at JAOO next week...
Steve_Hayes: @VenessaP I think they went out for noodles...
theRMK: Come speak with Matt at JAOO next week
drnic: reading my own abstract for JAOO presentation
quot;quot;quot;
1 scenario
1 failed step
3 passed steps

20. http://www.slideshare.net/bmabey/outsidein-development-with-cucumber

21. fetching JSON feed
def initial_json_data
Net::HTTP.get(URI.parse(quot;http://search.twitter.com/search.json?q=#{query}quot;))
end

22. fakeweb failure?!
Scenario: Display current search results
Given a safe folder
And twitter has some search results for quot;jaooquot;
When I run local executable quot;tweettailquot; with arguments quot;jaooquot;
getaddrinfo: nodename nor servname provided, or not known
(SocketError)
from .../net/http.rb:564:in `open'
...
from .../tweet-tail/lib/tweet-tail/tweet_poller.rb:24:in
`initial_json_data'
from .../tweet-tail/lib/tweet-tail/tweet_poller.rb:9:in `refresh'
from .../tweet-tail/lib/tweet-tail/cli.rb:39:in `execute'
from .../tweet-tail/bin/tweet-tail:10
Then I dump stdout

23. features/step_definitions/
common_steps.rb
When /^I run local executable quot;(.*)quot; with arguments quot;(.*)quot;/ do |exec, arguments|
@stdout = File.expand_path(File.join(@tmp_root, quot;executable.outquot;))
executable = File.expand_path(File.join(File.dirname(__FILE__), quot;/../../binquot;, exec))
in_project_folder do
system quot;ruby #{executable} #{arguments} > #{@stdout}quot;
end
end

24. Can I ignore a
There’s probably always something
you can’t quite test
Minimise that layer of code
Test the rest
bin main lib

25. Can I ignore a
There’s probably always something
you can’t quite test
Minimise that layer of code
Test the rest
bin main lib
1x sanity check

26. Can I ignore a
There’s probably always something
you can’t quite test
Minimise that layer of code
Test the rest
bin main lib
1x sanity check
all other integration tests
on internal code

27. bin/tweettail
ed to test this?
Do I ne
#!/usr/bin/env ruby
#
# Created on 2009-5-1 by Dr Nic Williams
# Copyright (c) 2009. All rights reserved.
require 'rubygems'
require File.expand_path(File.dirname(__FILE__) + quot;/../lib/tweet-tailquot;)
require quot;tweet-tail/cliquot;
TweetTail::CLI.execute(STDOUT, ARGV)

28. features/cli.feature
...
Scenario: Display current search results
Given twitter has some search results for 'jaoo'
When I run local executable 'tweettail' with arguments 'jaoo'
Then I should see
quot;quot;quot;
mattnhodges: Come speak with me at JAOO next week...
Steve_Hayes: @VenessaP I think they went out for...
theRMK: Come speak with Matt at JAOO next week...
drnic: reading my own abstract for JAOO presentation...
quot;quot;quot;

29. features/cli.feature
...
Scenario: Display some search results
Given a safe folder
And twitter has some search results for quot;jaooquot;
When I run local executable quot;tweettailquot; with arguments quot;jaooquot;
Then I should see some twitter messages
Scenario: Display explicit search results
Given a safe folder
And twitter has some search results for quot;jaooquot;
When I run executable internally with arguments quot;jaooquot;
Then I should see
quot;quot;quot;
mattnhodges: Come speak with me at JAOO next week
Steve_Hayes: @VenessaP I think they went out for
theRMK: Come speak with Matt at JAOO next week
drnic: reading my own abstract for JAOO presentation
quot;quot;quot;

30. end result
$ rake install_gem
$ tweettail jaoo
JAOO: Linda R.: I used to be a mathematician - I couldn't very well have started...
bengeorge: Global Financial Crisises are cool: jaoo tix down to 250 for 2 days.
kflund: First day of work at the JAOO Tutorials in Sydney - visiting the Opera House
wa7son: To my Copenhagen Ruby or Java colleagues: Get to meet Ola Bini at JAOO Geek Nights
ldaley: I am going to JAOO... awesome.
jessechilcott: @smallkathryn it's an IT conference. http://jaoo.com.au/sydney-2009/ .
scotartt: Looking forward to JAOO Brisbane next week - http://jaoo.com.au/brisbane-2009/
scotartt: JAOO Brisbane 2009 http://ff.im/-2B5ja
gwillis: @tweval I would give #jaoo a 10.0
rowanb: Bags almost packed for Sydney. Scrum User Group then JAOO. Driving there
mattnhodges: busy rest of week ahead. Spking @ Wiki Wed. Atlassian booth babe @ JAOO
conference Syd Thurs & Fri. Kiama 4 Jase's wedding all w'end #fb
pcalcado: searching twiter for #jaoo first impressions.
kornys: #jaoo has been excellent so far - though my tutorials have been full of
Steve_Hayes: RT @martinjandrews: women in rails - provide child care at #railsconf
CaioProiete: Wish I could be at #JAOO Australia...

31. ‘I run executable internally’ step
defn
When /^I run executable internally with arguments quot;(.*)quot;/ do |arguments|
require 'rubygems'
require File.dirname(__FILE__) + quot;/../../lib/tweet-tailquot;
require quot;tweet-tail/cliquot;
@stdout = File.expand_path(File.join(@tmp_root, quot;executable.outquot;))
in_project_folder do
TweetTail::CLI.execute(@stdout_io = StringIO.new, arguments.split(quot; quot;))
@stdout_io.rewind
File.open(@stdout, quot;wquot;) { |f| f << @stdout_io.read }
end
end

32. Many provided steps
Given /^a safe folder/ do
Given /^this project is active project folder/ do
Given /^env variable $([w_]+) set to quot;(.*)quot;/ do |env_var, value|
Given /quot;(.*)quot; folder is deleted/ do |folder|
When /^I invoke quot;(.*)quot; generator with arguments quot;(.*)quot;$/ do |generator, args|
When /^I run executable quot;(.*)quot; with arguments quot;(.*)quot;/ do |executable, args|
When /^I run project executable quot;(.*)quot; with arguments quot;(.*)quot;/ do |executable, args|
When /^I run local executable quot;(.*)quot; with arguments quot;(.*)quot;/ do |executable, args|
When /^I invoke task quot;rake (.*)quot;/ do |task|
Then /^folder quot;(.*)quot; (is|is not) created/ do |folder, is|
Then /^file quot;(.*)quot; (is|is not) created/ do |file, is|
Then /^file with name matching quot;(.*)quot; is created/ do |pattern|
Then /^file quot;(.*)quot; contents (does|does not) match /(.*)// do |file, does, regex|
Then /^(does|does not) invoke generator quot;(.*)quot;$/ do |does_invoke, generator|
Then /^I should see$/ do |text|
Then /^I should not see$/ do |text|
Then /^I should see exactly$/ do |text|
Then /^I should see all (d+) tests pass/ do |expected_test_count|
Then /^I should see all (d+) examples pass/ do |expected_test_count|
Then /^Rakefile can display tasks successfully/ do
Then /^task quot;rake (.*)quot; is executed successfully/ do |task|

33. ‘I should see...’
features/step_definitions/common_steps.rb
Then /^I should see$/ do |text|
actual_output = File.read(@stdout)
actual_output.should contain(text)
end
Then /^I should not see$/ do |text|
actual_output = File.read(@stdout)
actual_output.should_not contain(text)
end
Then /^I should see exactly$/ do |text|
actual_output = File.read(@stdout)
actual_output.should == text
end

34. ‘When I do something...’
features/step_definitions/common_steps.rb
When /^I run project executable quot;(.*)quot; with arguments quot;(.*)quot;/ do |executable, args|
@stdout = File.expand_path(File.join(@tmp_root, quot;executable.outquot;))
in_project_folder do
system quot;ruby #{executable} #{arguments} > #{@stdout}quot;
end
end
When /^I invoke task quot;rake (.*)quot;/ do |task|
@stdout = File.expand_path(File.join(@tmp_root, quot;tests.outquot;))
in_project_folder do
system quot;rake #{task} --trace > #{@stdout}quot;
end
end

35. ‘Given a safe folder...’
features/support/env.rb
Before do
@tmp_root = File.dirname(__FILE__) + quot;/../../tmpquot;
@home_path = File.expand_path(File.join(@tmp_root, quot;homequot;))
FileUtils.rm_rf @tmp_root
FileUtils.mkdir_p @home_path
ENV[quot;HOMEquot;] = @home_path
end

36. tweettail jaoo -f
polling please?
how to test polling?

37. features/cli.feature
Scenario: Poll for results until app cancelled
Given twitter has some search results for quot;jaooquot;
When I run executable internally with arguments quot;jaoo -fquot;
Then I should see
quot;quot;quot;
mattnhodges: Come speak with me at JAOO next week
Steve_Hayes: @VenessaP I think they went out for
theRMK: Come speak with Matt at JAOO next week
drnic: reading my own abstract for JAOO presentation
quot;quot;quot;
When the sleep period has elapsed
Then I should see
quot;quot;quot;
mattnhodges: Come speak with me at JAOO next week
Steve_Hayes: @VenessaP I think they went out for
theRMK: Come speak with Matt at JAOO next week
drnic: reading my own abstract for JAOO presentation
CaioProiete: Wish I could be at #JAOO Australia...
quot;quot;quot;
When I press quot;Ctrl-Cquot;
...

38. adding -f option
$ cucumber features/cli.feature:22
...
Scenario: Poll for results until app cancelled
Given twitter has some search results for quot;jaooquot;
When I run executable internally with arguments quot;jaoo -fquot;
invalid option: -f (OptionParser::InvalidOption)
lib/tweet-tail/cli.rb
module TweetTail::CLI
def self.execute(stdout, arguments=[])
options = { :polling => false }
parser = OptionParser.new do |opts|
opts.on(quot;-fquot;, quot;Poll for new search results each 15 seconds.quot;
) { |arg| options[:polling] = true }
opts.parse!(arguments)
end
app = TweetTail::TweetPoller.new(arguments.shift, options)
app.refresh
stdout.puts app.render_latest_results
end
end

39. features/fixtures/
search-jaoo-
{
quot;resultsquot;: [{
quot;textquot;: quot;Wish I could be at #JAOO Australia...quot;,
quot;from_userquot;: quot;CaioProietequot;,
quot;idquot;: 1711269079,
}],
quot;since_idquot;: 1682666650,
quot;refresh_urlquot;: quot;?since_id=1711269079&q=jaooquot;,
quot;queryquot;: quot;jaooquot;
}

40. features/step_definitions/
twitter_data_steps.rb
Given /^twitter has some search results for quot;([^quot;]*)quot;$/ do |query|
FakeWeb.register_uri(
:get,
quot;http://search.twitter.com/search.json?q=#{query}quot;,
:file => File.expand_path(File.dirname(__FILE__) +
quot;/../fixtures/search-#{query}.jsonquot;))
since = quot;1682666650quot;
FakeWeb.register_uri(
:get,
quot;http://search.twitter.com/search.json?since_id=#{since}&q=#{query}quot;,
:file => File.expand_path(File.dirname(__FILE__) +
quot;/../fixtures/search-#{query}-since-#{since}.jsonquot;))
end

41. hmm, sleep...
$ cucumber features/cli.feature:22
...
Scenario: Poll for results until app cancelled
Given twitter has some search results for quot;jaooquot;
When I run executable internally with arguments quot;jaoo -fquot;
Then I should see
quot;quot;quot;
mattnhodges: Come speak with me at JAOO next week - http://jaoo.dk/
Steve_Hayes: @VenessaP I think they went out for noodles. #jaoo
theRMK: Come speak with Matt at JAOO next week
drnic: reading my own abstract for JAOO presentation
quot;quot;quot;
When the sleep period has elapsed
Then I should see
quot;quot;quot;
mattnhodges: Come speak with me at JAOO next week - http://jaoo.dk/
Steve_Hayes: @VenessaP I think they went out for noodles. #jaoo
theRMK: Come speak with Matt at JAOO next week
drnic: reading my own abstract for JAOO presentation
CaioProiete: Wish I could be at #JAOO Australia...
quot;quot;quot;

42. features/cli.feature
Scenario: Poll for results until app cancelled
Given twitter has some search results for quot;jaooquot;
When I run executable internally with arguments quot;jaoo -fquot;
and wait 1 sleep cycle and quit
Then I should see
quot;quot;quot;
mattnhodges: Come speak with me at JAOO next week
Steve_Hayes: @VenessaP I think they went out for...
theRMK: Come speak with Matt at JAOO next week
drnic: reading my own abstract for JAOO presentation
CaioProiete: Wish I could be at #JAOO Australia...
quot;quot;quot;

43. features/step_definitions/executable_steps.rb
When /^I run executable internally with arguments quot;([^quot;]*)quot; and
wait (d+) sleep cycles? and quit$/ do |args, cycles|
hijack_sleep(cycles.to_i)
When %Q{I run executable internally with arguments quot;#{args}quot;}
end
features/support/time_machine_helpers.rb
module TimeMachineHelper
# expects sleep() to be called +cycles+ times, and then raises an Interrupt
def hijack_sleep(cycles)
results = [*1..cycles] # irrelevant truthy values for each sleep call
Kernel::stubs(:sleep).returns(*results).then.raises(Interrupt)
end
end
World(TimeMachineHelper)

44. using mocha
require quot;mochaquot;
World(Mocha::Standalone)
Before do
mocha_setup
end
After do
begin
mocha_verify
ensure
mocha_teardown
end
end
features/support/mocha.rb

45. working!
$ cucumber features/cli.feature:22
Feature: Live twitter search results on command line
In order to reduce cost of getting live search results
As a twitter user
I want twitter search results appearing in the console
Scenario: Poll for results until app cancelled
Given twitter has some search results for quot;jaooquot;
When I run executable internally with arguments quot;jaoo -fquot; and wait 1 sleep cycle and
quit
Then I should see
quot;quot;quot;
mattnhodges: Come speak with me at JAOO next week - http://jaoo.dk/
Steve_Hayes: @VenessaP I think they went out for noodles. #jaoo
theRMK: Come speak with Matt at JAOO next week
drnic: reading my own abstract for JAOO presentation
CaioProiete: Wish I could be at #JAOO Australia...
quot;quot;quot;
1 scenario (1 passed)
3 steps (3 passed)

47. Rakefile
task :default => [:features]
$ rake
(in /Users/drnic/Documents/ruby/gems/tweet-tail)
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby -w -
Ilib:ext:bin:test -e 'require quot;rubygemsquot;; require quot;test/unitquot;; require quot;test/
test_helper.rbquot;; require quot;test/test_tweet_poller.rbquot;'
Started
....
Finished in 0.002231 seconds.
4 tests, 10 assertions, 0 failures, 0 errors
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby -I quot;/Library/
Ruby/Gems/1.8/gems/cucumber-0.3.2/lib:libquot; ...
.................
5 scenarios (5 passed)
17 steps (17 passed)
Run unit tests + features

56. 1. Create account with
http://runcoderun.com
2. Press ‘Test Hook’

57. 1. Create account with
http://runcoderun.com
2. Press ‘Test Hook’

64. How to write tests/
stories for RubyGems
Dr Nic Williams
mocra.com
drnicwilliams.com
twitter: @drnic
drnic@mocra.com