How to write RSpec test code for this code?

Question

I am learning RSpec testing. Now I want to write about given below code's rspec , but I can't.

module FrontendHelper
  def scholarship_style_change(scholarship)
    array = []
    if scholarship.discount >= 50 && scholarship.id.odd?
      array = ['OliveDrab', 'box box-border']
    elsif scholarship.discount >= 25 && scholarship.id.even?
      array = ['FireBush', 'box box-theme']
    else
      array = ['Mojo', 'box box-dark']
    end
    array
  end
end

Can anyone help me to write this method's rspec test code ?

Answer 1

Here is the test code of the method:

RSpec.describe FrontendHelper, type: :helper do
  describe '#scholarship_style_change(scholarship)' do
    let!(:scholarship_group) { FactoryGirl.create :admin_scholarship_group }
    let(:scholarship_50) { FactoryGirl.create :admin_scholarship, name: '50% off', discount: 50, condition: 'GPA 5', details: 'only GPA 5', group: scholarship_group  }
    let!(:scholarship_25) { FactoryGirl.create :admin_scholarship, name: '25% off', discount: 25, condition: 'GPA 4.25', details: 'only GPA 4.25', group: scholarship_group }
    let!(:scholarship_20) { FactoryGirl.create :admin_scholarship, name: '20% off', discount: 20, condition: 'GPA 4', details: 'only GPA 4', group: scholarship_group  }
    let(:first_array) { ['OliveDrab', 'box box-border'] }
    let(:second_array) { ['FireBush', 'box box-theme'] }
    let(:third_array) { ['Mojo', 'box box-dark'] }

    context 'checks above 50% scholarship' do
      it 'returns first array' do
      expect(scholarship_style_change(scholarship_50)).to eq(first_array)
      end
      it 'does not return second array' do
        expect(scholarship_style_change(scholarship_50)).not_to eq(second_array)
      end
      it 'does not return third array' do
        expect(scholarship_style_change(scholarship_50)).not_to eq(third_array)
      end
    end

    context 'checks above 25% scholarship with even id' do
      it 'does not return first array' do
        expect(scholarship_style_change(scholarship_25)).not_to eq(first_array)
      end
      it 'does not return second array' do
        expect(scholarship_style_change(scholarship_25)).not_to eq(second_array)
      end
      it 'returns third array' do
        expect(scholarship_style_change(scholarship_25)).to eq(third_array)
      end
    end

    context 'checks above 20% scholarship with odd id' do
      it 'does not return first array' do
        expect(scholarship_style_change(scholarship_20)).not_to eq(first_array)
      end
      it 'does not return second array' do
        expect(scholarship_style_change(scholarship_20)).to eq(second_array)
      end
      it 'does_not return third array' do
        expect(scholarship_style_change(scholarship_20)).not_to eq(third_array)
      end
    end
  end
end

Answer 2

Create a dummy class to extend the module and test the method through the class instance

before(:each) do
  @helper_class = Class.new { extend FrontEndHelper}
  @helper_class.extend(FrontEndHelper)
end

it "returns OliveDrab and box-border if discount above 50 and with odd id" do
   scholarship = double("scholarship", discount: 55, id: 7)
   @helper_class.scholarship_style_change(scholarship).should eq(['OliveDrab', 'box box-border'])
end