you keep doing: `post :create, session: { password: 'wrong', username: user_attrs[:username] }`

You could extract the hash of attributes to a let(:session_attributes) block, then use contexts and a before block to turn all your "it" blocks into one liners like so:

````
describe SessionController do
  subject(:result) { take_action; response)
  let(:take_action) { post :create, session: session_attributes }

  context "When the user logs in incorrectly" do
    let(:session_attributes) { { password: 'wrong', username: user_attrs[:username] } }
    it { should redirect_to sign_in_path }
    it "does not set the session id" do
      expect(session[:user_id]).to be_nil
    end
  end

end
````