tea-time/presentation/06_context.slides

!SLIDE
# A little semantics game...

!SLIDE even-larger
``` coffeescript
describe 'Cat', ->
  describe '#meow', ->
    describe 'hungry', ->
      # cat codes

    describe 'going to the vet', ->
      # moar cat codes
```

!SLIDE
# This works, but it can be clearer

!SLIDE even-larger
``` ruby
describe Cat do
  describe '#meow' do
    describe 'hungry' do
      # cat codes
    end

    describe 'going to the vet' do
      # moar cat codes
    end
  end
end
```

!SLIDE
# `context`

!SLIDE
# Description of different states for a test

!SLIDE even-larger
``` ruby
alias :context :describe
```

!SLIDE even-larger
``` ruby
describe Cat do
  let(:cat) { described_class.new }

  # save describe for
  # things or behaviors...
  describe '#meow' do
    subject { cat.meow }

    # use context to describe states
    context 'hungry' do
      # cat codes
    end

    context 'going to the vet' do
      # moar cat codes
    end
  end
end
```

!SLIDE
# Jasmine doesn't have `context`

!SLIDE
# However...

!SLIDE even-larger
``` coffeescript
this.context = this.describe
```

!SLIDE even-larger
``` coffeescript
this.context = this.describe

describe 'Cat', ->
  describe '#meow', ->
    context 'hungry', ->
      # cat codes

    context 'going to the vet', ->
      # moar cat codes
```

!SLIDE larger
``` coffeescript
this.context = this.describe

describe 'Cat', ->
  describe '#meow', ->
    beforeEach ->
      @cat = new Cat()

    context 'hungry', ->
      it 'should be a mournful meow', ->
        @cat.state = -> Cat.HUNGRY

        expect(@cat.meow()).toEqual("meeeyaow")

    context 'going to the vet', ->
      it 'should be an evil meow', ->
        @cat.state = -> Cat.VET_PSYCHIC

        expect(@cat.meow()).toEqual("raowwww")
```

!SLIDE even-larger
``` coffeescript
class @Cat
  @HUNGRY = 'hungry'
  @VET_PSYCHIC = 'vet psychic'

  meow: ->
    switch this.state()
      when Cat.HUNGRY
        "meeeyaow"
      when Cat.VET_PSYCHIC
        "raowwww"
```

!SLIDE even-larger
```
2 spec, 0 failures
```