RSpec.describe SubDiff::Collection do
  subject { described_class.new(diffable) }

  let(:diffable) { 'this is a simple test' }

  describe '#changed?' do
    it 'should return true if any diffs have changed' do
      diff = double('diff', :changed? => true, :empty? => false)
      subject.push(diff)
      expect(subject).to be_changed
    end

    it 'should return false if no diffs have changed' do
      diff = double('diff', :changed? => false, :empty? => false)
      subject.push(diff)
      expect(subject).not_to be_changed
    end

    it 'should return false if there are no diffs' do
      expect(subject).not_to be_changed
    end
  end

  describe '#each' do
    it { is_expected.to be_an(Enumerable) }
    it { is_expected.to delegate(:each).to(:diffs) }
  end

  describe '#push' do
    it 'should append a diff' do
      diff = double('diff', :empty? => false)
      block = proc { subject.push(diff) }
      expect(block).to change(subject.diffs, :size)
    end

    it 'should not append an empty diff' do
      diff = double('diff', :empty? => true)
      block = proc { subject.push(diff) }
      expect(block).not_to change(subject.diffs, :size)
    end
  end

  describe '#size' do
    it { is_expected.to delegate(:size).to(:diffs) }

    it 'should not use the string size' do
      expect(subject.size).not_to eq(subject.to_s.size)
    end
  end

  describe '#__getobj__' do
    it 'should join the diff values if any' do
      subject.push('test')
      subject.push('example')
      expect(subject.__getobj__).to eq('testexample')
    end

    it 'should return the diffable if diffs are empty' do
      expect(subject.__getobj__).to eq(diffable)
    end
  end
end