require 'rails_helper' describe UploaderHelper do let(:uploader) do example_uploader = Class.new(CarrierWave::Uploader::Base) do include UploaderHelper storage :file end example_uploader.new end describe '#extension_match?' do it 'returns false if file does not exists' do expect(uploader.file).to be_nil expect(uploader.send(:extension_match?, 'jpg')).to eq false end end end