Delete unauthorized Todos when project is privateissue_49897

Delete Todos for guest users when project visibility
level is updated to private.

2 files changed, 28 insertions, 9 deletions

diff --git a/app/services/todos/destroy/base_service.rb b/app/services/todos/destroy/base_service.rb
index f3f1dbb5698..7378f10e7c4 100644
--- a/app/services/todos/destroy/base_service.rb
+++ b/app/services/todos/destroy/base_service.rb
@@ -13,7 +13,7 @@ module Todos
 
       # rubocop: disable CodeReuse/ActiveRecord
       def without_authorized(items)
-        items.where('user_id NOT IN (?)', authorized_users)
+        items.where('todos.user_id NOT IN (?)', authorized_users)
       end
       # rubocop: enable CodeReuse/ActiveRecord
 
diff --git a/app/services/todos/destroy/confidential_issue_service.rb b/app/services/todos/destroy/confidential_issue_service.rb
index 6276e332448..6cdd8c16894 100644
--- a/app/services/todos/destroy/confidential_issue_service.rb
+++ b/app/services/todos/destroy/confidential_issue_service.rb
@@ -2,36 +2,55 @@
 
 module Todos
   module Destroy
+    # Service class for deleting todos that belongs to confidential issues.
+    # It deletes todos for users that are not at least reporters, issue author or assignee.
+    #
+    # Accepts issue_id or project_id as argument.
+    # When issue_id is passed it deletes matching todos for one confidential issue.
+    # When project_id is passed it deletes matching todos for all confidential issues of the project.
     class ConfidentialIssueService < ::Todos::Destroy::BaseService
       extend ::Gitlab::Utils::Override
 
-      attr_reader :issue
+      attr_reader :issues
 
       # rubocop: disable CodeReuse/ActiveRecord
-      def initialize(issue_id)
-        @issue = Issue.find_by(id: issue_id)
+      def initialize(issue_id: nil, project_id: nil)
+        @issues =
+          if issue_id
+            Issue.where(id: issue_id)
+          elsif project_id
+            project_confidential_issues(project_id)
+          end
       end
       # rubocop: enable CodeReuse/ActiveRecord
 
       private
 
+      def project_confidential_issues(project_id)
+        project = Project.find(project_id)
+
+        project.issues.confidential_only
+      end
+
       override :todos
       # rubocop: disable CodeReuse/ActiveRecord
       def todos
-        Todo.where(target: issue)
-          .where('user_id != ?', issue.author_id)
-          .where('user_id NOT IN (?)', issue.assignees.select(:id))
+        Todo.joins_issue_and_assignees
+          .where(target: issues)
+          .where('issues.confidential = ?', true)
+          .where('todos.user_id != issues.author_id')
+          .where('todos.user_id != issue_assignees.user_id')
       end
       # rubocop: enable CodeReuse/ActiveRecord
 
       override :todos_to_remove?
       def todos_to_remove?
-        issue&.confidential?
+        issues&.any?(&:confidential?)
       end
 
       override :project_ids
       def project_ids
-        issue.project_id
+        issues&.distinct&.select(:project_id)
       end
 
       override :authorized_users