1.rb

describe 'テスト対象' do
  context '状態' do
    describe 'テスト対象メソッド' do
      context '与える入力' do
        it '期待する出力'
      end
    end
  end
end

2.rb

    its (:size) { should eq 10 }

3.rb

describe SymbolStack do
  context 'when stack is empty' do
  end

  context 'when stack is full' do
  end

  context 'when stack is not empty or full' do
  end
end

4.rb

describe SymbolStack do
  context 'when stack is empty' do
    describe 'SymbolStack#size' do
    end
    describe 'SymbolStack#push' do
    end
    describe 'SymbolStack#pop' do
    end
  end

  context 'when stack is full' do
    describe 'SymbolStack#size' do
    end
  # 以下省略

5.rb

describe SymbolStack do
  context 'when stack is empty' do
    describe 'SymbolStack#size' do
    end
    describe 'SymbolStack#push' do
      context 'with symbol' do
      end
      context 'with non-symbol' do
      end
    end
    describe 'SymbolStack#pop' do
    end
  # 以下省略

6.rb

describe SymbolStack do
  context 'when stack is empty' do
    describe 'SymbolStack#size' do
      it 'returns 0'
    end
    describe 'SymbolStack#push' do
      context 'with symbol' do
        it 'increments stack size'
      end
      context 'with non-symbol' do
        it 'raise error'
      end
    end
    describe 'SymbolStack#pop' do
      it 'raise error'
    end
  # 以下省略

7.rb

describe SymbolStack do
  context 'when stack is empty' do
# 中略
  context 'when stack is full' do
    before do
      10.times {|i| subject.push(:"data#{i}") }
    end
# 中略
  context 'when stack is not empty or full' do
    before do
      subject.push(:data)
    end
# 以下省略

8.rb

describe SymbolStack do
  context 'when stack is empty' do
    describe 'SymbolStack#size' do
      it 'returns 0' do
        subject.size.should eq 0
      end
    end

    describe 'SymbolStack#push' do
      context 'with symbol' do
        it 'increments stack size' do
          expect { subject.push(:data) }.
            to change { subject.size }.from(0).to(1)
        end
      end

      context 'with non-symbol' do
        it 'raise error' do
          expect { subject.push('data') }.to raise_error
        end
      end
    end

    describe 'SymbolStack#pop' do
      it 'raise error' do
        expect { subject.pop }.to raise_error
      end
    end
  end
# 以下省略

9.rb

      it 'returns 0' do
        subject.size.should eq 0
      end