Testing Merb
The Right Way

Why Test?

TDD

TDD and Regressions

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

Resiliant Against Refactoring

class Awesome
def hello
puts \"~ Hello ~\"
end
end
describe Awesome do
it \"prints hello\" do
awesome = Awesome.new
awesome.should_receive(:puts)
awesome.hello
end
end

class Awesome
def hello
awesome_print \"~ Hello ~\"
end
def awesome_print(str)
print \"#{str}\\n\"
end
end
describe Awesome do
it \"prints hello\" do
awesome = Awesome.new
awesome.should_receive(:puts)
awesome.hello
end
end

class Awesome
def hello
awesome_print \"~ Hello ~\"
end
def awesome_print(str)
print \"#{str}\\n\"
end
end
describe Awesome do
it \"prints hello\" do
AIL
awesome = Awesome.new
F
awesome.should_receive(:puts)
awesome.hello
end
end

class Awesome
def hello
awesome_print \"~ Hello ~\"
end
def awesome_print(str)
print \"#{str}\\n\"
end
end
describe Awesome do
it \"prints hello\" do
capture { Awesome.new.hello }.
should =~ /Hello/
end
end

How to Test Three Rules

Broken Interface means failing tests

Working Interface means passing tests

Write tests about what you care about

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

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

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

Iteration 1

class Foo < Application
def awesome
awesome_string
end
def awesome_string
\"Awesome\"
end
end
Merb::Router.prepare do
match(\"/foo/awesome\").
to(:controller => Foo,
:action => :awesome).
name(:awesome)
end

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

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

Iteration 2

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

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

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

request(\"/foo/awesome\").body.
should =~ /Awesome/

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

Broken Interface means failing tests

Working Interface means passing tests

Write tests about what you care about

“It’s Too Hard”

Let’s Make it Easy

request(url(:speakers))
request(resource(@speaker))
request(\"/foo/speakers\")

request(url(:speakers))
one method
request(resource(@speaker))
request(\"/foo/speakers\")

Sessions are automatically sticky in a spec

it \"should let you in\" do
request(\"/login\", :method => :post,
:params => {:username => \"user\",
:password => \"pass\"})
request(\"/home\").should be_successful
end

it \"should let you in\" do
request(\"/login\", :method => :post,
:params => {:username => \"user\",
:password => \"pass\"})
request(\"/home\").should be_successful
login
end

it \"should let you in\" do
request(\"/login\", :method => :post,
:params => {:username => \"user\",
:password => \"pass\"})
request(\"/home\").should be_successful
end
you’re logged in

describe \"/login\", :given => \"successful login\" do
it \"should let you in\" do
request(\"/home\").should be_successful
end
end
simpler

describe \"/login\", :given => \"successful login\" do
it \"should let you in\" do
request(\"/home\").should be_successful
end
end
simpler

Request
Rack
status body headers

request() helper
Rack
status body headers

request(\"/foo\").body.should == \"hello\"
request(\"/foo\").should have_xpath(\"//h1\")
request(\"/foo\").should(
have_selector(\"h1:contains(text)\"))

request(\"/foo\").body.should == \"hello\"
request(\"/foo\").should have_xpath(\"//h1\")
request(\"/foo\").should(
have_selector(\"h1:contains(text)\"))
1.0 final

request(\"/foo\").should be_client_error
request(\"/foo\").should(
have_content_type(:json))

Thank you.