Writing tests / specs on Ruby

car_model_api_service_spec.rb

require 'rails_helper'

describe CarModelAPIService do
  shared_examples_for 'fetch method' do
    it { is_expected.to eq(result) }
  end
  describe '#fetch' do
    subject { CarModelAPIService.new(params).fetch }

    context 'when params is xxx' do
      let(:params) { { year_made: '2000', price_min: 10_000, price_max: 100_000 } }
      let(:result) { [{ make: 'Honda', model: 'Accord'}] }

      it_behaves_like 'fetch method'
    end

    context 'when params is yyy' do
      let(:params) { { year_made: '2009', price_min: 30_000, price_max: 50_000 } }
      let(:result) { [{ make: 'Honda', model: 'Civic'}] }

      it_behaves_like 'fetch method'
    end
  end
end