User spec with implicit subject

user_spec.rb

describe User do
  describe "#can_do_dangerous_stuff?" do
    subject { user.can_do_dangerous_stuff? }

    context "when the User is a customer" do
      let(:user) { User.new("customer") }
      it { should be_false }
    end

    context "when the User is an admin" do
      let(:user) { User.new("admin") }
      it { should be_true }
    end
  end
end