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About testing
What?programmers?think...
 ?I'm?not?going?to?write?all?those?tests?
 It's?really?simple?code,?it?doesn't?need?to?be?tested
 Testing?is?a?waste?of?time
 I've?done?this?(loop/data?retrieval/functionalty,?etc)?
millions?of?times

About testing
What?Project?managers?may??think...
 We?test?after?the?code?is?done
 That's?what?we?have?a?testing?person?for
 We?can't?spend?that?time?now

What's it about?
 Writing?specifications?of?what?we?are?going?to?do
 It?means?we?specify?the?behaviour?of?our?code
 Specifying?a?small?aspects?in?a?concise,?
unambiguous,?and?executable?form

Domain?Specific?Language?for?describing?the?
expected?behaviour?of?a?system?with?executable?
examples.
?you:?Describe?a?new?account
?client:?It?should?have?zero?balance
Rspec

In?Rspec:
???????describe?"A?new?Account"?do
?????????it?"should?have?0?balance"?do
????????????account?=?Account.new
????????????account.balance.should?==?0.0
??????????end
????????end
Rspec

expectation
An expression of how an object is expected to
behave
code example
An executable example of how the code can be
used, and its expected behaviour (expressed with
expectations) in a given context
example group A group of code examples
spec or spec file A file contains one or more example groups
Rspec

Test::Unit Rspec
class DogTest describe Dog
def test_bark It 'should bark'
assert_xxx object.should_be xxx
def setup before(:each) {}
def teardown dfter(:each){}
Rspec

Describe it..
describe()
 example?group
 receives?any?number?of?arguments?and?a?block
 generally??two?arguments?that?represent?the?object?and?
its?behaviour
 first?argument?can?be?a?class?or?module?or?a?string
 second?one?is?optional?but?it?must?be?a?string
 returns?a?sub?class?of?Spec::Example::ExampleGroup

Describe it..
describe()
Ex:
 describe?'A?Book'?{?}?#?=>?A?Book
 describe?Book?{?}?#?=>?Book
 describe?Book,?'without?price?tag'?{}?#?=>?Book?without?
price?tag

Describe it..
it()
 code?example
 receives?string?as?first?argument,?option?hash?and?
optional?block
 string?can?be?a?sentence?that?will?represent?the?detail?
of?the?code?within?the?block
 pending()
● keep?list?of?specifications?to?be?verified
● it()?method?with?no?block
● Calling?pending()?midst?of?the?code?example

Before and After
 before
● grouping?things?by?initial?state
● ?before(:each){}?executed?before?executing?every?
example
● before(:all){}?executed?before?executing?all?the?
examples?in?the?example?group
 after
● ?after(:each){}?executed?after?executing?every?example
● ?after(:all){}?executing?after?executing?all?the?examples?
in?the?example?group

Before and After
 useful?to?remove?duplicates
 improving?the?clarity
 making?the?examples?easier?to?understand

Helper methods
 another?way?to?have?our?examples?clean
 can?move?same?line?of?code?to?helper?methods
 fails?in?readability,?go?somewhere?to?refer?the?method
 shared?helper?methods?used?to?share?helper?methods?
across?example?groups?by?defining?in?a?module?and?
including?it

Nested example groups
 ?a?way?to?organize?example?groups?in?a?spec
?describe?"outer"?do
?????describe?"inner"?{}
??end
 outer?group?is?a?sub?class?of?ExampleGroup
 inner?group?is?the?sub?class?of?outer?group
 everything?declared?in?outer?group?will?be?available?to?
inner?group

Expectations
 ?expression?of?how?the?object?is?expected?to?behave
 describing?an?expectation?of?what?should?happen?
rather?than?what?will?happen
 should?&?should_not

Matchers
 ?Equality
● a.should?==?b
● a.should?===?b
● a.should?eql?b
● a.should?equal?b
 Floating?point
● ?result.should?be_within(5.25).of(0.005)

Matchers
 Multi?line?text
● result.should?match?/regexp/
● result.should?=~?/regexp/
 Arrays?and?hashes
● array.should?include(2)

Matchers
 Changes
● lambda{}.should?change{}
● make?more?explicit?by?to(),?by()?and?from()
 Expecting?errors
● lambda{}.should?raise_error()
● raise_error?will?receive?0,1?or?2?arguments

Matchers
 Predicate?Matchers
● ?a?method?name?ends?with?'?'?and?returns?boolean?is?
called?predicate?matchers
● ?array.empty?.should?==?true?#?here?predicate?method?is?expected?
to?return?true
● ?array.should?be_empty
● ??will?work?for?any?predicate?method,?with?argument?
also

Matchers
 ?Have
● has_[predicate?method]?=>?have_[name]
● hash.has_key?(id).should?==?true??
● hash.should?have_key(id)
● when?describing?object?itself?a?collection
– ???team.should?have(11).players_on_the_field
● Strings
– ?"this?string".should?have(11).characters

Generated Description
 in?few?cases,?example?docstring?is?nearly?matches?
with?the?expectation?in?the?example
 can?use?Rspec?auto?generated?example?name
 specify()?more?readable?than?it()
 both?are?aliases?of?example()

Subjectivity
 subject?of?an?example?is?the?object?being?described
 subject?is?an?instance?of?the?class?which?is?specified?in?
example?group
 it?is?initiated?in?the?before?block

Rspec-Mock
 mock?objects?are?imitation?objects
 gives?control?over?their?behaviour?during?the?
execution?of?an?example
 isolates?our?examples?from?services?that?are
complex?to?set?up?or?expensive?to?run
 Rspec?comes?with?a?built?in?mock?object?framework

Rspec-Mock
 Stub
● returns?pre?determined?value
 Ex
● book.stub(:title)?{?"The?RSpec?Book"?}
● book.stub(:title?=>?"The?RSpec?Book")
● book.stub(:title).and_return("The?RSpec?Book")

Rspec-Mock
 Consecutive?return?values
● more?than?one?value?can?be?provided?to?and_return()
● Last?value?will?be?return?for?subsequent?matches
 Ex
● die.stub(:roll).and_return(1,2,3)
● die.roll?#?=>?1
● die.roll?#?=>?2
● die.roll?#?=>?3
● die.roll?#?=>?3

Rspec-Mock
 Message?expectations
● is?an?expectations
● if?expected?message?is?not?received,?example?will?fail
 Ex
● Channel.should_receive(:new).with(params)

Rspec-Rails
 gem?install?rspec?rails
 rails?generate?rspec:install

Rspec-Tips
 describe?your?methods
● describe?".authenticate"?do
● describe?"#admin?"?do
 use?contexts
 single?expectation

References
 The?Rspec?Book?by?David?chelimsky
 http://github.com/rspec/rspec
 http://github.com/rspec/rspec?rails

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