Merge topics with same name

Changelog: changed

db/post_migrate/20220223124428_schedule_merge_topics_with_same_name.rb

+# frozen_string_literal: true
+
+class ScheduleMergeTopicsWithSameName < Gitlab::Database::Migration[1.0]
+  MIGRATION = 'MergeTopicsWithSameName'
+  BATCH_SIZE = 100
+
+  disable_ddl_transaction!
+
+  class Topic < ActiveRecord::Base
+    self.table_name = 'topics'
+  end
+
+  def up
+    Topic.select('LOWER(name) as name').group('LOWER(name)').having('COUNT(*) > 1').order('LOWER(name)')
+    .in_groups_of(BATCH_SIZE, false).each_with_index do |group, i|
+      migrate_in((i + 1) * 2.minutes, MIGRATION, [group.map(&:name)])
+    end
+  end
+
+  def down
+    # no-op
+  end
+end

db/schema_migrations/20220223124428

+8fb72b15bfaa1b58f87cb3f1836df1e8bfa1a5ddec4e480a2cb6a3c9fafe3bda
\ No newline at end of file

lib/gitlab/background_migration/merge_topics_with_same_name.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    # The class to merge project topics with the same case insensitive name
+    class MergeTopicsWithSameName
+      # Temporary AR model for topics
+      class Topic < ActiveRecord::Base
+        self.table_name = 'topics'
+      end
+
+      # Temporary AR model for project topic assignment
+      class ProjectTopic < ActiveRecord::Base
+        self.table_name = 'project_topics'
+      end
+
+      def perform(topic_names)
+        topic_names.each do |topic_name|
+          topics = Topic.where('LOWER(name) = ?', topic_name)
+            .order(total_projects_count: :desc, non_private_projects_count: :desc, id: :asc)
+            .to_a
+          topic_to_keep = topics.shift
+          merge_topics(topic_to_keep, topics) if topics.any?
+        end
+      end
+
+      private
+
+      def merge_topics(topic_to_keep, topics_to_remove)
+        description = topic_to_keep.description
+
+        topics_to_remove.each do |topic|
+          description ||= topic.description if topic.description.present?
+          process_avatar(topic_to_keep, topic) if topic.avatar.present?
+
+          ProjectTopic.transaction do
+            ProjectTopic.where(topic_id: topic.id)
+              .where.not(project_id: ProjectTopic.where(topic_id: topic_to_keep).select(:project_id))
+              .update_all(topic_id: topic_to_keep.id)
+            ProjectTopic.where(topic_id: topic.id).delete_all
+          end
+        end
+
+        Topic.where(id: topics_to_remove).delete_all
+
+        topic_to_keep.update(
+          description: description,
+          total_projects_count: total_projects_count(topic_to_keep.id),
+          non_private_projects_count: non_private_projects_count(topic_to_keep.id)
+        )
+      end
+
+      # We intentionally use application code here because we need to copy/remove avatar files
+      def process_avatar(topic_to_keep, topic_to_remove)
+        topic_to_remove = ::Projects::Topic.find(topic_to_remove.id)
+        topic_to_keep = ::Projects::Topic.find(topic_to_keep.id)
+        unless topic_to_keep.avatar.present?
+          topic_to_keep.avatar = topic_to_remove.avatar
+          topic_to_keep.save!
+        end
+
+        topic_to_remove.remove_avatar!
+        topic_to_remove.save!
+      end
+
+      def total_projects_count(topic_id)
+        ProjectTopic.where(topic_id: topic_id).count
+      end
+
+      def non_private_projects_count(topic_id)
+        ProjectTopic.joins('INNER JOIN projects ON project_topics.project_id = projects.id')
+            .where(project_topics: { topic_id: topic_id }).where('projects.visibility_level in (10, 20)').count
+      end
+    end
+  end
+end

spec/lib/gitlab/background_migration/merge_topics_with_same_name_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::BackgroundMigration::MergeTopicsWithSameName, schema: 20220223124428 do
+  def set_avatar(topic_id, avatar)
+    topic = ::Projects::Topic.find(topic_id)
+    topic.avatar = avatar
+    topic.save!
+    topic.avatar.absolute_path
+  end
+
+  it 'merges project topics with same case insensitive name' do
+    namespaces = table(:namespaces)
+    projects = table(:projects)
+    topics = table(:topics)
+    project_topics = table(:project_topics)
+
+    group = namespaces.create!(name: 'group', path: 'group')
+    project_1 = projects.create!(namespace_id: group.id, visibility_level: 20)
+    project_2 = projects.create!(namespace_id: group.id, visibility_level: 10)
+    project_3 = projects.create!(namespace_id: group.id, visibility_level: 0)
+    topic_1_keep = topics.create!(
+      name: 'topic1',
+      description: 'description 1 to keep',
+      total_projects_count: 2,
+      non_private_projects_count: 2
+    )
+    topic_1_remove = topics.create!(
+      name: 'TOPIC1',
+      description: 'description 1 to remove',
+      total_projects_count: 2,
+      non_private_projects_count: 1
+    )
+    topic_2_remove = topics.create!(
+      name: 'topic2',
+      total_projects_count: 0
+    )
+    topic_2_keep = topics.create!(
+      name: 'TOPIC2',
+      description: 'description 2 to keep',
+      total_projects_count: 1
+    )
+    topic_3_remove_1 = topics.create!(
+      name: 'topic3',
+      total_projects_count: 2,
+      non_private_projects_count: 1
+    )
+    topic_3_keep = topics.create!(
+      name: 'Topic3',
+      total_projects_count: 2,
+      non_private_projects_count: 2
+    )
+    topic_3_remove_2 = topics.create!(
+      name: 'TOPIC3',
+      description: 'description 3 to keep',
+      total_projects_count: 2,
+      non_private_projects_count: 1
+    )
+    topic_4_keep = topics.create!(
+      name: 'topic4'
+    )
+
+    project_topics_1 = []
+    project_topics_3 = []
+    project_topics_removed = []
+
+    project_topics_1 << project_topics.create!(topic_id: topic_1_keep.id, project_id: project_1.id)
+    project_topics_1 << project_topics.create!(topic_id: topic_1_keep.id, project_id: project_2.id)
+    project_topics_removed << project_topics.create!(topic_id: topic_1_remove.id, project_id: project_2.id)
+    project_topics_1 << project_topics.create!(topic_id: topic_1_remove.id, project_id: project_3.id)
+
+    project_topics_3 << project_topics.create!(topic_id: topic_3_keep.id, project_id: project_1.id)
+    project_topics_3 << project_topics.create!(topic_id: topic_3_keep.id, project_id: project_2.id)
+    project_topics_removed << project_topics.create!(topic_id: topic_3_remove_1.id, project_id: project_1.id)
+    project_topics_3 << project_topics.create!(topic_id: topic_3_remove_1.id, project_id: project_3.id)
+    project_topics_removed << project_topics.create!(topic_id: topic_3_remove_2.id, project_id: project_1.id)
+    project_topics_removed << project_topics.create!(topic_id: topic_3_remove_2.id, project_id: project_3.id)
+
+    avatar_paths = {
+      topic_1_keep: set_avatar(topic_1_keep.id, fixture_file_upload('spec/fixtures/avatars/avatar1.png')),
+      topic_1_remove: set_avatar(topic_1_remove.id, fixture_file_upload('spec/fixtures/avatars/avatar2.png')),
+      topic_2_remove: set_avatar(topic_2_remove.id, fixture_file_upload('spec/fixtures/avatars/avatar3.png')),
+      topic_3_remove_1: set_avatar(topic_3_remove_1.id, fixture_file_upload('spec/fixtures/avatars/avatar4.png')),
+      topic_3_remove_2: set_avatar(topic_3_remove_2.id, fixture_file_upload('spec/fixtures/avatars/avatar5.png'))
+    }
+
+    subject.perform(%w[topic1 topic2 topic3 topic4])
+
+    # Topics
+    [topic_1_keep, topic_2_keep, topic_3_keep, topic_4_keep].each(&:reload)
+    expect(topic_1_keep.name).to eq('topic1')
+    expect(topic_1_keep.description).to eq('description 1 to keep')
+    expect(topic_1_keep.total_projects_count).to eq(3)
+    expect(topic_1_keep.non_private_projects_count).to eq(2)
+    expect(topic_2_keep.name).to eq('TOPIC2')
+    expect(topic_2_keep.description).to eq('description 2 to keep')
+    expect(topic_2_keep.total_projects_count).to eq(0)
+    expect(topic_2_keep.non_private_projects_count).to eq(0)
+    expect(topic_3_keep.name).to eq('Topic3')
+    expect(topic_3_keep.description).to eq('description 3 to keep')
+    expect(topic_3_keep.total_projects_count).to eq(3)
+    expect(topic_3_keep.non_private_projects_count).to eq(2)
+    expect(topic_4_keep.reload.name).to eq('topic4')
+
+    [topic_1_remove, topic_2_remove, topic_3_remove_1, topic_3_remove_2].each do |topic|
+      expect { topic.reload }.to raise_error(ActiveRecord::RecordNotFound)
+    end
+
+    # Topic avatars
+    expect(topic_1_keep.avatar).to eq('avatar1.png')
+    expect(File.exist?(::Projects::Topic.find(topic_1_keep.id).avatar.absolute_path)).to be_truthy
+    expect(topic_2_keep.avatar).to eq('avatar3.png')
+    expect(File.exist?(::Projects::Topic.find(topic_2_keep.id).avatar.absolute_path)).to be_truthy
+    expect(topic_3_keep.avatar).to eq('avatar4.png')
+    expect(File.exist?(::Projects::Topic.find(topic_3_keep.id).avatar.absolute_path)).to be_truthy
+
+    [:topic_1_remove, :topic_2_remove, :topic_3_remove_1, :topic_3_remove_2].each do |topic|
+      expect(File.exist?(avatar_paths[topic])).to be_falsey
+    end
+
+    # Project Topic assignments
+    project_topics_1.each do |project_topic|
+      expect(project_topic.reload.topic_id).to eq(topic_1_keep.id)
+    end
+
+    project_topics_3.each do |project_topic|
+      expect(project_topic.reload.topic_id).to eq(topic_3_keep.id)
+    end
+
+    project_topics_removed.each do |project_topic|
+      expect { project_topic.reload }.to raise_error(ActiveRecord::RecordNotFound)
+    end
+  end
+end

spec/migrations/20220223124428_schedule_merge_topics_with_same_name_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+require_migration!
+
+RSpec.describe ScheduleMergeTopicsWithSameName do
+  let(:topics) { table(:topics) }
+
+  describe '#up' do
+    before do
+      stub_const("#{described_class}::BATCH_SIZE", 2)
+
+      topics.create!(name: 'topic1')
+      topics.create!(name: 'Topic2')
+      topics.create!(name: 'Topic3')
+      topics.create!(name: 'Topic4')
+      topics.create!(name: 'topic2')
+      topics.create!(name: 'topic3')
+      topics.create!(name: 'topic4')
+      topics.create!(name: 'TOPIC2')
+      topics.create!(name: 'topic5')
+    end
+
+    it 'schedules MergeTopicsWithSameName background jobs', :aggregate_failures do
+      Sidekiq::Testing.fake! do
+        freeze_time do
+          migrate!
+
+          expect(described_class::MIGRATION).to be_scheduled_delayed_migration(2.minutes, %w[topic2 topic3])
+          expect(described_class::MIGRATION).to be_scheduled_delayed_migration(4.minutes, %w[topic4])
+          expect(BackgroundMigrationWorker.jobs.size).to eq(2)
+        end
+      end
+    end
+  end
+end