Running all specs is time consuming. Sometimes even depending on live reload (e.g with guard) does not cut it. Fortunately you have control over the spec to be run.

Suppose that you working on two displays. On the first one: Vim. The other? Let’s use it to run our specs!

" Copy file path to clipboard
noremap <silent> <F4> :let @+=expand("%:p")<CR>

While being editing user_spec.rb, press F4.

require 'spec_helper'

describe User, type: :model do

  let(:user) { create(:user) }

  describe '#full_name_or_email' do
    before { user.update_attribute(:email, 'joe@example.com') }

    subject { user.full_name_or_email }

    it { is_expected.to eq 'joe@example.com' }
  end
end

Now switch to the other display, type: rspec and paste the file path with Cmd V.

You can even scope the spec down to the concrete case adding a line number like:
rspec spec/models/user_spec.rb:42.
This protip has been written in 894 seconds