require 'spec_helper' describe Gitlab::Utils::StrongMemoize do let(:klass) do struct = Struct.new(:value) do def method_name strong_memoize(:method_name) do trace << value value end end def trace @trace ||= [] end end struct.include(described_class) struct end subject(:object) { klass.new(value) } shared_examples 'caching the value' do it 'only calls the block once' do value0 = object.method_name value1 = object.method_name expect(value0).to eq(value) expect(value1).to eq(value) expect(object.trace).to contain_exactly(value) end it 'returns and defines the instance variable for the exact value' do returned_value = object.method_name memoized_value = object.instance_variable_get(:@method_name) expect(returned_value).to eql(value) expect(memoized_value).to eql(value) end end describe '#strong_memoize' do [nil, false, true, 'value', 0, [0]].each do |value| context "with value #{value}" do let(:value) { value } it_behaves_like 'caching the value' end end end describe '#clear_memoization' do let(:value) { 'mepmep' } it 'removes the instance variable' do object.method_name object.clear_memoization(:method_name) expect(object.instance_variable_defined?(:@method_name)).to be(false) end end end