Remove todos of users without access to targets migration

changelogs/unreleased/todos-visibility-migration.yml

+---
+title: Remove todos of users without access to targets migration
+merge_request: 20927
+author:
+type: other

db/migrate/20180717125853_remove_restricted_todos.rb

+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+# frozen_string_literal: true
+
+class RemoveRestrictedTodos < ActiveRecord::Migration
+  DOWNTIME = false
+  disable_ddl_transaction!
+
+  MIGRATION = 'RemoveRestrictedTodos'.freeze
+  BATCH_SIZE = 1000
+  DELAY_INTERVAL = 5.minutes.to_i
+
+  class Project < ActiveRecord::Base
+    include EachBatch
+
+    self.table_name = 'projects'
+  end
+
+  def up
+    Project.where('EXISTS (SELECT 1 FROM todos WHERE todos.project_id = projects.id)')
+      .each_batch(of: BATCH_SIZE) do |batch, index|
+      range = batch.pluck('MIN(id)', 'MAX(id)').first
+
+      BackgroundMigrationWorker.perform_in(index * DELAY_INTERVAL, MIGRATION, range)
+    end
+  end
+
+  def down
+    # nothing to do
+  end
+end

lib/gitlab/background_migration/remove_restricted_todos.rb

+# frozen_string_literal: true
+# rubocop:disable Style/Documentation
+
+module Gitlab
+  module BackgroundMigration
+    class RemoveRestrictedTodos
+      PRIVATE_FEATURE = 10
+      PRIVATE_PROJECT = 0
+
+      class Project < ActiveRecord::Base
+        self.table_name = 'projects'
+      end
+
+      class ProjectAuthorization < ActiveRecord::Base
+        self.table_name = 'project_authorizations'
+      end
+
+      class ProjectFeature < ActiveRecord::Base
+        self.table_name = 'project_features'
+      end
+
+      class Todo < ActiveRecord::Base
+        include EachBatch
+
+        self.table_name = 'todos'
+      end
+
+      class Issue < ActiveRecord::Base
+        include EachBatch
+
+        self.table_name = 'issues'
+      end
+
+      def perform(start_id, stop_id)
+        projects = Project.where('EXISTS (SELECT 1 FROM todos WHERE todos.project_id = projects.id)')
+          .where(id: start_id..stop_id)
+
+        projects.each do |project|
+          remove_confidential_issue_todos(project.id)
+
+          if project.visibility_level == PRIVATE_PROJECT
+            remove_non_members_todos(project.id)
+          else
+            remove_restricted_features_todos(project.id)
+          end
+        end
+      end
+
+      private
+
+      def remove_non_members_todos(project_id)
+        Todo.where(project_id: project_id)
+          .where('user_id NOT IN (?)', authorized_users(project_id))
+          .each_batch(of: 5000) do |batch|
+            batch.delete_all
+          end
+      end
+
+      def remove_confidential_issue_todos(project_id)
+        # min access level to access a confidential issue is reporter
+        min_reporters = authorized_users(project_id)
+          .select(:user_id)
+          .where('access_level >= ?', 20)
+
+        confidential_issues = Issue.select(:id, :author_id).where(confidential: true, project_id: project_id)
+        confidential_issues.each_batch(of: 100) do |batch|
+          batch.each do |issue|
+            assigned_users = IssueAssignee.select(:user_id).where(issue_id: issue.id)
+
+            todos = Todo.where(target_type: 'Issue', target_id: issue.id)
+              .where('user_id NOT IN (?)', min_reporters)
+              .where('user_id NOT IN (?)', assigned_users)
+            todos = todos.where('user_id != ?', issue.author_id) if issue.author_id
+
+            todos.delete_all
+          end
+        end
+      end
+
+      def remove_restricted_features_todos(project_id)
+        ProjectFeature.where(project_id: project_id).each do |project_features|
+          target_types = []
+          target_types << 'Issue' if private?(project_features.issues_access_level)
+          target_types << 'MergeRequest' if private?(project_features.merge_requests_access_level)
+          target_types << 'Commit' if private?(project_features.repository_access_level)
+
+          next if target_types.empty?
+
+          Todo.where(project_id: project_id)
+            .where('user_id NOT IN (?)', authorized_users(project_id))
+            .where(target_type: target_types)
+            .delete_all
+        end
+      end
+
+      def private?(feature_level)
+        feature_level == PRIVATE_FEATURE
+      end
+
+      def authorized_users(project_id)
+        ProjectAuthorization.select(:user_id).where(project_id: project_id)
+      end
+    end
+  end
+end

spec/lib/gitlab/background_migration/remove_restricted_todos_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::BackgroundMigration::RemoveRestrictedTodos, :migration, schema: 20180704204006 do
+  let(:projects)               { table(:projects) }
+  let(:users)                  { table(:users) }
+  let(:todos)                  { table(:todos) }
+  let(:issues)                 { table(:issues) }
+  let(:assignees)              { table(:issue_assignees) }
+  let(:project_authorizations) { table(:project_authorizations) }
+  let(:project_features)       { table(:project_features) }
+
+  let(:todo_params) { { author_id: 1, target_type: 'Issue', action: 1, state: :pending } }
+
+  before do
+    users.create(id: 1, email: 'user@example.com', projects_limit: 10)
+    users.create(id: 2, email: 'reporter@example.com', projects_limit: 10)
+    users.create(id: 3, email: 'guest@example.com', projects_limit: 10)
+
+    projects.create!(id: 1, name: 'project-1', path: 'project-1', visibility_level: 0, namespace_id: 1)
+    projects.create!(id: 2, name: 'project-2', path: 'project-2', visibility_level: 0, namespace_id: 1)
+
+    issues.create(id: 1, project_id: 1)
+    issues.create(id: 2, project_id: 2)
+
+    project_authorizations.create(user_id: 2, project_id: 2, access_level: 20) # reporter
+    project_authorizations.create(user_id: 3, project_id: 2, access_level: 10) # guest
+
+    todos.create(todo_params.merge(user_id: 1, project_id: 1, target_id: 1)) # out of project ids range
+    todos.create(todo_params.merge(user_id: 1, project_id: 2, target_id: 2)) # non member
+    todos.create(todo_params.merge(user_id: 2, project_id: 2, target_id: 2)) # reporter
+    todos.create(todo_params.merge(user_id: 3, project_id: 2, target_id: 2)) # guest
+  end
+
+  subject { described_class.new.perform(2, 5) }
+
+  context 'when a project is private' do
+    it 'removes todos of users without project access' do
+      expect { subject }.to change { Todo.count }.from(4).to(3)
+    end
+
+    context 'with a confidential issue' do
+      it 'removes todos of users without project access and guests for confidential issues' do
+        issues.create(id: 3, project_id: 2, confidential: true)
+        issues.create(id: 4, project_id: 1, confidential: true) # not in the batch
+        todos.create(todo_params.merge(user_id: 3, project_id: 2, target_id: 3))
+        todos.create(todo_params.merge(user_id: 2, project_id: 2, target_id: 3))
+        todos.create(todo_params.merge(user_id: 1, project_id: 1, target_id: 4))
+
+        expect { subject }.to change { Todo.count }.from(7).to(5)
+      end
+    end
+  end
+
+  context 'when a project is public' do
+    before do
+      projects.find(2).update_attribute(:visibility_level, 20)
+    end
+
+    context 'when all features have the same visibility as the project, no confidential issues' do
+      it 'does not remove any todos' do
+        expect { subject }.not_to change { Todo.count }
+      end
+    end
+
+    context 'with confidential issues' do
+      before do
+        users.create(id: 4, email: 'author@example.com', projects_limit: 10)
+        users.create(id: 5, email: 'assignee@example.com', projects_limit: 10)
+        issues.create(id: 3, project_id: 2, confidential: true, author_id: 4)
+        assignees.create(user_id: 5, issue_id: 3)
+
+        todos.create(todo_params.merge(user_id: 1, project_id: 2, target_id: 3)) # to be deleted
+        todos.create(todo_params.merge(user_id: 2, project_id: 2, target_id: 3)) # authorized user
+        todos.create(todo_params.merge(user_id: 3, project_id: 2, target_id: 3)) # to be deleted guest
+        todos.create(todo_params.merge(user_id: 4, project_id: 2, target_id: 3)) # conf issue author
+        todos.create(todo_params.merge(user_id: 5, project_id: 2, target_id: 3)) # conf issue assignee
+      end
+
+      it 'removes confidential issue todos for non authorized users' do
+        expect { subject }.to change { Todo.count }.from(9).to(7)
+      end
+    end
+
+    context 'features visibility restrictions' do
+      before do
+        todo_params.merge!(project_id: 2, user_id: 1, target_id: 3)
+        todos.create(todo_params.merge(user_id: 1, target_id: 3, target_type: 'MergeRequest'))
+        todos.create(todo_params.merge(user_id: 1, target_id: 3, target_type: 'Commit'))
+      end
+
+      context 'when issues are restricted to project members' do
+        before do
+          project_features.create(issues_access_level: 10, project_id: 2)
+        end
+
+        it 'removes non members issue todos' do
+          expect { subject }.to change { Todo.count }.from(6).to(5)
+        end
+      end
+
+      context 'when merge requests are restricted to project members' do
+        before do
+          project_features.create(merge_requests_access_level: 10, project_id: 2)
+        end
+
+        it 'removes non members issue todos' do
+          expect { subject }.to change { Todo.count }.from(6).to(5)
+        end
+      end
+
+      context 'when repository and merge requests are restricted to project members' do
+        before do
+          project_features.create(repository_access_level: 10, merge_requests_access_level: 10, project_id: 2)
+        end
+
+        it 'removes non members commit and merge requests todos' do
+          expect { subject }.to change { Todo.count }.from(6).to(4)
+        end
+      end
+    end
+  end
+end