shared_examples 'a operator with a single input value' do |arguments|
  include_context 'variables are initialized', arguments, *%w(variable_value expected_number expected_tex expected_number_text expected_gnu)
  let(:variable) { { name: "X", value: variable_value } }
  let(:subject) do
    described_class.new(variable)
  end

  describe '#to_f' do
    context 'when variables are not numbers but have value' do
      it 'returns the division of the values' do
        expect(subject.to_f).to eq(expected_number)
      end

      it do
        expect(subject.to_f).to be_a(Float)
      end
    end

    context 'when the variable is a number' do
      let(:variable) { variable_value }

      it 'returns the squared root of the value' do
        expect(subject.to_f).to eq(expected_number)
      end

      it do
        expect(subject.to_f).to be_a(Float)
      end
    end
  end

  describe '#to_tex' do
    context 'when variables have no value' do
      let(:variable) { :X }

      it 'returns a latex format fraction' do
        expect(subject.to_tex).to eq(expected_tex)
      end
    end

    context 'when the variable is numeric' do
      before do
        subject.variables[0].value = variable_value
      end
      it 'prints both numbers' do
        expect(subject.to_tex).to eq(expected_number_text)
      end
    end
  end

  describe '#to_gnu' do
    context 'when variables have no value' do
      let(:variable) { :X }

      it 'returns a latex format fraction' do
        expect(subject.to_gnu).to eq(expected_gnu)
      end
    end

    context 'when the variable is numeric' do
      before do
        subject.variables[0].value = variable_value
      end
      it 'prints both numbers' do
        expect(subject.to_gnu).to eq(expected_number_text)
      end
    end
  end
end