Fix specs and improve code style

app/controllers/sessions_controller.rb

@@ -112,18 +112,19 @@ class SessionsController < Devise::SessionsController
   end
 
   def gitlab_geo_login
-    if !signed_in? && Gitlab::Geo.enabled? && Gitlab::Geo.secondary?
-      oauth = Gitlab::Geo::OauthSession.new
+    return if signed_in? || !Gitlab::Geo.secondary?
+    oauth = Gitlab::Geo::OauthSession.new
 
-      # share full url with primary node by shared session
-      user_return_to = URI.join(root_url, session[:user_return_to].to_s).to_s
-      oauth.return_to = @redirect_to || user_return_to
+    # share full url with primary node by shared session
+    user_return_to = URI.join(root_url, session[:user_return_to].to_s).to_s
+    oauth.return_to = @redirect_to || user_return_to
 
-      redirect_to oauth_geo_auth_url(state: oauth.generate_oauth_state)
-    end
+    redirect_to oauth_geo_auth_url(state: oauth.generate_oauth_state)
   end
 
   def gitlab_geo_logout
+    return unless Gitlab::Geo.secondary?
+
     oauth = Gitlab::Geo::OauthSession.new(access_token: session[:access_token])
     @geo_logout_state = oauth.generate_logout_state
   end

lib/gitlab/geo/oauth_session.rb

@@ -17,11 +17,14 @@ module Gitlab
 
       def generate_oauth_state
         return unless return_to
+
         hmac = generate_oauth_hmac(oauth_salt, return_to)
         "#{oauth_salt}:#{hmac}:#{return_to}"
       end
 
       def generate_logout_state
+        return unless access_token
+
         cipher = logout_token_cipher(oauth_salt, :encrypt)
         encrypted = cipher.update(access_token) + cipher.final
         "#{oauth_salt}:#{Base64.urlsafe_encode64(encrypted)}"
@@ -29,6 +32,7 @@ module Gitlab
 
       def extract_logout_token
         return unless state
+
         salt, encrypted = state.split(':', 2)
         decipher = logout_token_cipher(salt, :decrypt)
         decipher.update(Base64.urlsafe_decode64(encrypted)) + decipher.final
@@ -57,6 +61,7 @@ module Gitlab
 
       def generate_oauth_hmac(salt, return_to)
         return false unless return_to
+        
         digest = OpenSSL::Digest.new('sha256')
         key = Gitlab::Application.secrets.secret_key_base + salt
         OpenSSL::HMAC.hexdigest(digest, key, return_to)

spec/lib/gitlab/geo/oauth_session_spec.rb

@@ -64,6 +64,10 @@ describe Gitlab::Geo::OauthSession do
   describe '#generate_logout_state' do
     subject { described_class.new(access_token: access_token) }
 
+    it 'returns nil when access_token is not defined' do
+      expect(described_class.new.generate_logout_state).to be_nil
+    end
+
     it 'returns a string with salt and encrypted access token colon separated' do
       state = subject.generate_logout_state
       expect(state).to be_a String