This document discusses test-driven development (TDD) in Merb applications. It emphasizes that tests should focus on the essential functionality and behavior that the developer cares about, rather than implementation details. Tests should continue passing even as the code is refactored. The document provides examples of refactoring code while keeping tests passing. It also suggests ways to make testing easier, such as adding helper methods to simplify request assertions and maintain test session state.

1. Testing Merb
The Right Way

2. Why Test?

3. TDD

4. TDD and Regressions

5. TDD and Regressions
I am not saying
TDD is bad, but
this talk doesn’t
focus on mock-
driven TDD.

6. Resiliant Against Refactoring

7. class Awesome
def hello
puts quot;~ Hello ~quot;
end
end
describe Awesome do
it quot;prints helloquot; do
awesome = Awesome.new
awesome.should_receive(:puts)
awesome.hello
end
end

8. class Awesome
def hello
awesome_print quot;~ Hello ~quot;
end
def awesome_print(str)
print quot;#{str}nquot;
end
end
describe Awesome do
it quot;prints helloquot; do
awesome = Awesome.new
awesome.should_receive(:puts)
awesome.hello
end
end

9. class Awesome
def hello
awesome_print quot;~ Hello ~quot;
end
def awesome_print(str)
print quot;#{str}nquot;
end
end
describe Awesome do
it quot;prints helloquot; do
AIL
awesome = Awesome.new
F
awesome.should_receive(:puts)
awesome.hello
end
end

10. class Awesome
def hello
awesome_print quot;~ Hello ~quot;
end
def awesome_print(str)
print quot;#{str}nquot;
end
end
describe Awesome do
it quot;prints helloquot; do
capture { Awesome.new.hello }.
should =~ /Hello/
end
end

11. How to Test Three Rules

12. Broken Interface means failing tests

13. Working Interface means passing tests

14. Write tests about what you care about

15. http://example.com/foo
Filters
Controller
Views
Helpers
What Happens in Your App

16. http://example.com/foo
Your App
What You Care About

17. http://example.com/foo
4 Filters
Controller
H Views Partials
Helpers
Refactoring

18. Iteration 1

19. class Foo < Application
def awesome
awesome_string
end
def awesome_string
quot;Awesomequot;
end
end
Merb::Router.prepare do
match(quot;/foo/awesomequot;).
to(:controller => Foo,
:action => :awesome).
name(:awesome)
end

20. dispatch_to(Foo, :awesome) do |cont|
cont.should_receive(:awesome_string)
end

21. dispatch_to(Foo, :awesome) do |cont|
cont.should_receive(:awesome_string)
end

22. Iteration 2

23. class Bar < Application
def coolness
render
end
end
Merb::Router.prepare do
match(quot;/foo/awesomequot;).
to(:controller => Bar,
:action => :coolness).
name(:awesome)
end

24. dispatch_to(Foo, :awesome) do |cont|
cont.should_receive(:awesome_string)
end

25. dispatch_to(Foo, :awesome) do |cont|
AIL
cont.should_receive(:awesome_string)
end
F

26. request(quot;/foo/awesomequot;).body.
should =~ /Awesome/

27. request(url(:awesome)).body.
should =~ /Awesome/

28. Broken Interface means failing tests

29. Working Interface means passing tests

30. Write tests about what you care about

31. “It’s Too Hard”

32. Let’s Make it Easy

33. request(url(:speakers))
request(resource(@speaker))
request(quot;/foo/speakersquot;)

34. request(url(:speakers))
one method
request(resource(@speaker))
request(quot;/foo/speakersquot;)

35. Sessions are automatically sticky in a spec

36. it quot;should let you inquot; do
request(quot;/loginquot;, :method => :post,
:params => {:username => quot;userquot;,
:password => quot;passquot;})
request(quot;/homequot;).should be_successful
end

37. it quot;should let you inquot; do
request(quot;/loginquot;, :method => :post,
:params => {:username => quot;userquot;,
:password => quot;passquot;})
request(quot;/homequot;).should be_successful
login
end

38. it quot;should let you inquot; do
request(quot;/loginquot;, :method => :post,
:params => {:username => quot;userquot;,
:password => quot;passquot;})
request(quot;/homequot;).should be_successful
end
you’re logged in

39. describe quot;/loginquot;, :given => quot;successful loginquot; do
it quot;should let you inquot; do
request(quot;/homequot;).should be_successful
end
end
simpler

40. describe quot;/loginquot;, :given => quot;successful loginquot; do
it quot;should let you inquot; do
request(quot;/homequot;).should be_successful
end
end
simpler

41. Request
Rack
status body headers

42. request() helper
Rack
status body headers

43. request(quot;/fooquot;).body.should == quot;helloquot;
request(quot;/fooquot;).should have_xpath(quot;//h1quot;)
request(quot;/fooquot;).should(
have_selector(quot;h1:contains(text)quot;))

44. request(quot;/fooquot;).body.should == quot;helloquot;
request(quot;/fooquot;).should have_xpath(quot;//h1quot;)
request(quot;/fooquot;).should(
have_selector(quot;h1:contains(text)quot;))
1.0 final

45. request(quot;/fooquot;).should be_client_error
request(quot;/fooquot;).should(
have_content_type(:json))

46. Thank you.