Reduce database writes in credentials_controller specs

Makes smarter use of factories to create
objects only where required to improve overall
running time of this file and database writes.

ee/spec/controllers/admin/credentials_controller_spec.rb

@@ -3,10 +3,14 @@
 require 'spec_helper'
 
 RSpec.describe Admin::CredentialsController do
+  let_it_be(:admin) { create(:admin) }
+  let_it_be(:user) { create(:user) }
+  let_it_be(:personal_access_token) { create(:personal_access_token, user: user) }
+
   describe 'GET #index' do
     context 'admin user' do
       before do
-        sign_in(create(:admin))
+        sign_in(admin)
       end
 
       context 'when `credentials_inventory` feature is enabled' do
@@ -26,13 +30,13 @@ RSpec.describe Admin::CredentialsController do
         end
 
         describe 'filtering by type of credential' do
-          let_it_be(:personal_access_tokens) { create_list(:personal_access_token, 2) }
+          let_it_be(:personal_access_tokens) { create_list(:personal_access_token, 2, user: user) }
 
           shared_examples_for 'filtering by `personal_access_tokens`' do
             specify do
               get :index, params: params
 
-              expect(assigns(:credentials)).to match_array(personal_access_tokens)
+              expect(assigns(:credentials)).to match_array(user.personal_access_tokens)
             end
           end
 
@@ -56,7 +60,7 @@ RSpec.describe Admin::CredentialsController do
 
           context 'credential type specified as `ssh_keys`' do
             it 'filters by ssh keys' do
-              ssh_keys =  create_list(:personal_key, 2)
+              ssh_keys =  create_list(:personal_key, 2, user: user)
 
               get :index, params: { filter: 'ssh_keys' }
 
@@ -81,7 +85,7 @@ RSpec.describe Admin::CredentialsController do
 
     context 'non-admin user' do
       before do
-        sign_in(create(:user))
+        sign_in(user)
       end
 
       it 'returns 404' do
@@ -94,10 +98,8 @@ RSpec.describe Admin::CredentialsController do
 
   describe 'PUT #revoke' do
     context 'admin user' do
-      let_it_be(:current_user) { create(:admin) }
-
       before do
-        sign_in(current_user)
+        sign_in(admin)
       end
 
       context 'when `credentials_inventory` feature is enabled' do
@@ -115,11 +117,9 @@ RSpec.describe Admin::CredentialsController do
 
         describe 'with an existing personal access token' do
           context 'does not have permissions to revoke the credential' do
-            let_it_be(:personal_access_token) { create(:personal_access_token) }
-
             before do
-              expect(Ability).to receive(:allowed?).with(current_user, :log_in, :global) { true }
-              expect(Ability).to receive(:allowed?).with(current_user, :revoke_token, personal_access_token) { false }
+              allow(Ability).to receive(:allowed?).with(admin, :log_in, :global) { true }
+              allow(Ability).to receive(:allowed?).with(admin, :revoke_token, personal_access_token) { false }
             end
 
             it 'returns the flash error message' do
@@ -131,7 +131,7 @@ RSpec.describe Admin::CredentialsController do
           end
 
           context 'personal access token is already revoked' do
-            let_it_be(:personal_access_token) { create(:personal_access_token, revoked: true) }
+            let_it_be(:personal_access_token) { create(:personal_access_token, revoked: true, user: user) }
 
             it 'returns the flash success message' do
               put :revoke, params: { id: personal_access_token.id }
@@ -142,7 +142,7 @@ RSpec.describe Admin::CredentialsController do
           end
 
           context 'personal access token is already expired' do
-            let_it_be(:personal_access_token) { create(:personal_access_token, expires_at: 5.days.ago) }
+            let_it_be(:personal_access_token) { create(:personal_access_token, expires_at: 5.days.ago, user: user) }
 
             it 'returns the flash success message' do
               put :revoke, params: { id: personal_access_token.id }
@@ -153,8 +153,6 @@ RSpec.describe Admin::CredentialsController do
           end
 
           context 'personal access token is not revoked or expired' do
-            let_it_be(:personal_access_token) { create(:personal_access_token) }
-
             it 'returns the flash success message' do
               put :revoke, params: { id: personal_access_token.id }
 
@@ -166,8 +164,6 @@ RSpec.describe Admin::CredentialsController do
       end
 
       context 'when `credentials_inventory` feature is disabled' do
-        let_it_be(:personal_access_token) { create(:personal_access_token) }
-
         before do
           stub_licensed_features(credentials_inventory: false)
         end
@@ -181,10 +177,8 @@ RSpec.describe Admin::CredentialsController do
     end
 
     context 'non-admin user' do
-      let_it_be(:personal_access_token) { create(:personal_access_token) }
-
       before do
-        sign_in(create(:user))
+        sign_in(user)
       end
 
       it 'returns 404' do