require 'rails_helper' module Tables RSpec.describe DiscomfortCalculator do let(:calculator) { described_class.new(table) } describe '#cohesion_penalty' do context 'when the table contains just two guests' do let(:table) do [ create(:guest, affinity_group_list: ['family']), create(:guest, affinity_group_list: ['friends']) ] end before do allow(AffinityGroupsHierarchy.instance).to receive(:distance).and_return(distance) end context 'when they belong to the same group' do let(:distance) { 0 } it { expect(calculator.send(:cohesion_penalty)).to eq(0) } end context 'when they belong to completely unrelated groups' do let(:distance) { nil } it { expect(calculator.send(:cohesion_penalty)).to eq(1) } end context 'when they belong to groups at a distance of 1' do let(:distance) { 1 } it { expect(calculator.send(:cohesion_penalty)).to eq(0.5) } end context 'when they belong to groups at a distance of 2' do let(:distance) { 2 } it { expect(calculator.send(:cohesion_penalty)).to eq(Rational(2, 3)) } end context 'when they belong to groups at a distance of 3' do let(:distance) { 3 } it { expect(calculator.send(:cohesion_penalty)).to eq(Rational(3, 4)) } end end end end end