require "spec_helper" describe UserForm do it "..." do params = { user: { email: 'email@gmail.com', address: { street: "street1" }, comments: [ { body: "body1" }, { body: "body2" } ] } } user_form = UserAndCommentsForm.new(params[:user]) expect(user_form.address.nil?).to eq(false) expect(user_form.comments.length).to eq(2) end end