Fix Rails/SaveBang Rubocop offenses for mattermost modules

Contributes to https://gitlab.com/gitlab-org/gitlab/-/issues/220040

.rubocop_manual_todo.yml

@@ -283,9 +283,6 @@ Rails/SaveBang:
     - 'spec/lib/gitlab/markdown_cache/redis/store_spec.rb'
     - 'spec/lib/gitlab/middleware/go_spec.rb'
     - 'spec/lib/gitlab/shard_health_cache_spec.rb'
-    - 'spec/lib/mattermost/command_spec.rb'
-    - 'spec/lib/mattermost/session_spec.rb'
-    - 'spec/lib/mattermost/team_spec.rb'
     - 'spec/mailers/notify_spec.rb'
     - 'spec/models/appearance_spec.rb'
     - 'spec/models/application_record_spec.rb'

changelogs/unreleased/issue-220040-fix-rails-savebang-mattermost-module.yml

+---
+title: Fix Rails/SaveBang Rubocop offenses for mattermost modules
+merge_request: 58048
+author: Huzaifa Iftikhar @huzaifaiftikhar
+type: fixed

spec/lib/mattermost/command_spec.rb

@@ -19,7 +19,7 @@ RSpec.describe Mattermost::Command do
         trigger: 'gitlab' }
     end
 
-    subject { described_class.new(nil).create(params) }
+    subject { described_class.new(nil).create(params) } # rubocop:disable Rails/SaveBang
 
     context 'for valid trigger word' do
       before do

spec/lib/mattermost/session_spec.rb

@@ -39,7 +39,7 @@ RSpec.describe Mattermost::Session, type: :request do
 
     context 'with oauth_uri' do
       let!(:doorkeeper) do
-        Doorkeeper::Application.create(
+        Doorkeeper::Application.create!(
           name: 'GitLab Mattermost',
           redirect_uri: "#{mattermost_url}/signup/gitlab/complete\n#{mattermost_url}/login/gitlab/complete",
           scopes: '')

spec/lib/mattermost/team_spec.rb

@@ -71,7 +71,7 @@ RSpec.describe Mattermost::Team do
   end
 
   describe '#create' do
-    subject { described_class.new(nil).create(name: "devteam", display_name: "Dev Team", type: "O") }
+    subject { described_class.new(nil).create(name: "devteam", display_name: "Dev Team", type: "O") } # rubocop:disable Rails/SaveBang
 
     context 'for a new team' do
       let(:response) do