An RSpec 3 Talk - Speaker Deck

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An RSpec 3 Talk

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a!/samphippen

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RSpec RSpec ! ! RSpec 3

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Upgrading

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The easiest major gem upgrade you’ve ever done

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The upgrade process

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Be green and warning free on RSpec 2

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gem “rspec”, “~> 2.99”

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bundle install

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fix warnings

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gem “rspec”, “~> 3.0”

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Done.

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There is also Transpec

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Verifying doubles

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Who’s ever stubbed an object’s interface wrong?

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class Foo def bar(beers) “#{beers} bottles of beer” end end

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allow(Foo.new).to receive(:bare)

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class Foo def bar(beers) “#{beers} bottles of beer” end end

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allow(Foo.new).to receive(:bar).with(1,2)

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Not enabled by default for upgrade installs

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RSpec.configure do |config| config.mock_with :rspec do |mocks| mocks.verify_partial_doubles = true end end

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http://tinyurl.com/p6yk8ll

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Verifying behaviour on pure doubles

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double( :some_name_for_the_double, :call => :result )

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instance_double( MyClass, :call => :result )

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instance_double( MyClass, :call => :result )

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instance_double( “MyClass”, :call => :result )

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Let’s have some questions !!/samphippen [email protected]

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Also class_double and object_double

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Composable matchers

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One Expectation Per Test

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expect(json[“foo”]).to eq(bar) expect(json[“baz”]).to eq(quz) expect(json[“boz”][“buz”]).to match(id_regex)

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expect(json[“foo”]).to eq(bar) expect(json[“baz”]).to eq(quz) expect(json[“boz”][“buz”]).to match(id_regex)

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Could write separate tests

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That could be expensive

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expect(json).to match( “foo” => bar, “baz” => quz, “boz” => { “buz” => match(id_regex) } )

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Match parts of hashes and arrays

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{ “key” => { “key1” => value1, “key2” => value2, } }

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expect(foo).to match( “key” => a_hash_including( “key2”=> value2 ) )

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{ “key” => [1,2,3] }

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expect(foo).to match( “key” => an_array_including(1) )

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Compound expressions via and and or

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expect(alphabet).to start_with("a") expect(alphabet).to end_with("z")

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expect(alphabet) .to start_with(“a”) .and end_with("z")

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expect(stoplight.color) .to eq(“red") .or eq(“green") .or eq("yellow")

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Nearly all existing RSpec matchers are composable

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Works with custom matchers

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Rails

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Let’s have some questions !!/samphippen [email protected]

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OMG. Loading rails is the worst thing ever

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files took 2.09 seconds to load

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spec_helper is now split

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spec_helper.rb Loads RSpec, not your app

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rails_helper.rb Loads RSpec + whole rails app

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Spec Types

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RSpec rails used to be highly implicit

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#spec/controllers/foo_controller_spec.rb describe FooController it “magically has get and assigns methods????” get :index expect(assigns[:foo]).to be true end end

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#spec/controllers/foo_controller_spec.rb describe FooController, :type => :controller it “gets the methods from the metadata” get :index expect(assigns[:foo]).to be true end end

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This applies to all Rails spec types

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You can structure your specs however you like

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If you badly need directory based spec inference

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RSpec.configure do |config| conﬁg.infer_spec_type_from_ﬁle_location! end

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http://tinyurl.com/kgllgtb

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RSpec is trying to get less bad at patching methods on to everything for you

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Sytnax

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The “a.should == b” syntax is not gone

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It is deprecated

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I strongly advise you to use expect(a).to eq(b) everywhere

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a.should == b expect(a).to eq(b)

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a.should_receive(:foo) expect(a).to receive(:foo)

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a.stub(:foo) allow(a).to receive(:foo)

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expect { }.to raise_error ! #is the same

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a.any_instance.stub(:foo) allow_any_instance_of(a).to receive(:foo)

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a.any_instance.should_receive(:foo) expect_any_instance_of(a).to receive(:foo)

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RSpec also now has a “no monkey patching” mode

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RSpec 2 monkey patches #describe

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describe “” do describe “” do end it “” do end end

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RSpec.describe “” do describe “” do end it “” do end end

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bare describe is still available in RSpec contexts

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This one might trip you up

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be_true be_false

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be_truthy be_falsy be_falsey

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be true be false

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Let’s have some questions a!/samphippen [email protected]