Merge branch 'cablett-247867-epics-relative-position' into 'master'

Add EpicBoardPosition with relative positioning

See merge request gitlab-org/gitlab!48120

changelogs/unreleased/cablett-247867-epics-relative-position.yml

+---
+title: Add Epic Board Position model to store relative positioning of epics on a board
+merge_request: 48120
+author:
+type: added

db/migrate/20201202003042_add_epic_board_positions.rb

+# frozen_string_literal: true
+
+class AddEpicBoardPositions < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def up
+    with_lock_retries do
+      create_table :boards_epic_board_positions do |t|
+        t.references :epic_board, foreign_key: { to_table: :boards_epic_boards, on_delete: :cascade }, null: false, index: false
+        t.references :epic, foreign_key: { on_delete: :cascade }, null: false, index: true
+        t.integer :relative_position
+
+        t.timestamps_with_timezone null: false
+
+        t.index [:epic_board_id, :epic_id], unique: true, name: :index_boards_epic_board_positions_on_epic_board_id_and_epic_id
+      end
+    end
+  end
+
+  def down
+    with_lock_retries do
+      drop_table :boards_epic_board_positions
+    end
+  end
+end

db/schema_migrations/20201202003042

+779effb1db70aa8b9a24942ec3e0681064c01b69ee4731f82477c54361a670b0
\ No newline at end of file

db/structure.sql

@@ -9864,6 +9864,24 @@ CREATE SEQUENCE boards_epic_board_labels_id_seq
 
 ALTER SEQUENCE boards_epic_board_labels_id_seq OWNED BY boards_epic_board_labels.id;
 
+CREATE TABLE boards_epic_board_positions (
+    id bigint NOT NULL,
+    epic_board_id bigint NOT NULL,
+    epic_id bigint NOT NULL,
+    relative_position integer,
+    created_at timestamp with time zone NOT NULL,
+    updated_at timestamp with time zone NOT NULL
+);
+
+CREATE SEQUENCE boards_epic_board_positions_id_seq
+    START WITH 1
+    INCREMENT BY 1
+    NO MINVALUE
+    NO MAXVALUE
+    CACHE 1;
+
+ALTER SEQUENCE boards_epic_board_positions_id_seq OWNED BY boards_epic_board_positions.id;
+
 CREATE TABLE boards_epic_boards (
     id bigint NOT NULL,
     hide_backlog_list boolean DEFAULT false NOT NULL,
@@ -17920,6 +17938,8 @@ ALTER TABLE ONLY boards ALTER COLUMN id SET DEFAULT nextval('boards_id_seq'::reg
 
 ALTER TABLE ONLY boards_epic_board_labels ALTER COLUMN id SET DEFAULT nextval('boards_epic_board_labels_id_seq'::regclass);
 
+ALTER TABLE ONLY boards_epic_board_positions ALTER COLUMN id SET DEFAULT nextval('boards_epic_board_positions_id_seq'::regclass);
+
 ALTER TABLE ONLY boards_epic_boards ALTER COLUMN id SET DEFAULT nextval('boards_epic_boards_id_seq'::regclass);
 
 ALTER TABLE ONLY boards_epic_user_preferences ALTER COLUMN id SET DEFAULT nextval('boards_epic_user_preferences_id_seq'::regclass);
@@ -18953,6 +18973,9 @@ ALTER TABLE ONLY board_user_preferences
 ALTER TABLE ONLY boards_epic_board_labels
     ADD CONSTRAINT boards_epic_board_labels_pkey PRIMARY KEY (id);
 
+ALTER TABLE ONLY boards_epic_board_positions
+    ADD CONSTRAINT boards_epic_board_positions_pkey PRIMARY KEY (id);
+
 ALTER TABLE ONLY boards_epic_boards
     ADD CONSTRAINT boards_epic_boards_pkey PRIMARY KEY (id);
 
@@ -20582,6 +20605,10 @@ CREATE INDEX index_boards_epic_board_labels_on_epic_board_id ON boards_epic_boar
 
 CREATE INDEX index_boards_epic_board_labels_on_label_id ON boards_epic_board_labels USING btree (label_id);
 
+CREATE UNIQUE INDEX index_boards_epic_board_positions_on_epic_board_id_and_epic_id ON boards_epic_board_positions USING btree (epic_board_id, epic_id);
+
+CREATE INDEX index_boards_epic_board_positions_on_epic_id ON boards_epic_board_positions USING btree (epic_id);
+
 CREATE INDEX index_boards_epic_boards_on_group_id ON boards_epic_boards USING btree (group_id);
 
 CREATE INDEX index_boards_epic_user_preferences_on_board_id ON boards_epic_user_preferences USING btree (board_id);
@@ -23844,6 +23871,9 @@ ALTER TABLE ONLY approver_groups
 ALTER TABLE ONLY packages_tags
     ADD CONSTRAINT fk_rails_1dfc868911 FOREIGN KEY (package_id) REFERENCES packages_packages(id) ON DELETE CASCADE;
 
+ALTER TABLE ONLY boards_epic_board_positions
+    ADD CONSTRAINT fk_rails_1ecfd9f2de FOREIGN KEY (epic_id) REFERENCES epics(id) ON DELETE CASCADE;
+
 ALTER TABLE ONLY geo_repository_created_events
     ADD CONSTRAINT fk_rails_1f49e46a61 FOREIGN KEY (project_id) REFERENCES projects(id) ON DELETE CASCADE;
 
@@ -24771,6 +24801,9 @@ ALTER TABLE ONLY gpg_signatures
 ALTER TABLE ONLY board_group_recent_visits
     ADD CONSTRAINT fk_rails_ca04c38720 FOREIGN KEY (board_id) REFERENCES boards(id) ON DELETE CASCADE;
 
+ALTER TABLE ONLY boards_epic_board_positions
+    ADD CONSTRAINT fk_rails_cb4563dd6e FOREIGN KEY (epic_board_id) REFERENCES boards_epic_boards(id) ON DELETE CASCADE;
+
 ALTER TABLE ONLY vulnerability_finding_links
     ADD CONSTRAINT fk_rails_cbdfde27ce FOREIGN KEY (vulnerability_occurrence_id) REFERENCES vulnerability_occurrences(id) ON DELETE CASCADE;
 

ee/app/models/boards/epic_board.rb

@@ -4,6 +4,7 @@ module Boards
   class EpicBoard < ApplicationRecord
     belongs_to :group, optional: false, inverse_of: :epic_boards
     has_many :epic_board_labels, foreign_key: :epic_board_id, inverse_of: :epic_board
+    has_many :epic_board_positions, foreign_key: :epic_board_id, inverse_of: :epic_board
 
     validates :name, length: { maximum: 255 }
   end

ee/app/models/boards/epic_board_position.rb

+# frozen_string_literal: true
+
+module Boards
+  class EpicBoardPosition < ApplicationRecord
+    include RelativePositioning
+
+    belongs_to :epic_board, optional: false, inverse_of: :epic_board_positions
+    belongs_to :epic, optional: false
+
+    alias_attribute :parent, :epic_board
+    validates :epic, uniqueness: { scope: :epic_board_id }
+
+    scope :order_relative_position, -> do
+      reorder('relative_position ASC', 'id DESC')
+    end
+
+    def self.relative_positioning_query_base(position)
+      where(epic_board_id: position.epic_board_id)
+    end
+
+    def self.relative_positioning_parent_column
+      :epic_board_id
+    end
+  end
+end

ee/spec/factories/epic_board_positions.rb

+# frozen_string_literal: true
+
+FactoryBot.define do
+  factory :epic_board_position, class: 'Boards::EpicBoardPosition' do
+    epic
+    epic_board
+    relative_position { RelativePositioning::START_POSITION }
+  end
+end

ee/spec/factories/epic_boards.rb

+# frozen_string_literal: true
+
+FactoryBot.define do
+  factory :epic_board, class: 'Boards::EpicBoard' do
+    name
+    group
+  end
+end

ee/spec/models/boards/epic_board_position_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Boards::EpicBoardPosition do
+  let_it_be(:epic) { create(:epic) }
+  let_it_be(:group) { create(:group) }
+  let_it_be(:epic_board) { create(:epic_board, group: group) }
+  let_it_be(:epic_board_position) { create(:epic_board_position, epic: epic, epic_board: epic_board) }
+
+  describe 'associations' do
+    subject { build(:epic_board_position) }
+
+    it { is_expected.to belong_to(:epic).required }
+    it { is_expected.to belong_to(:epic_board).required.inverse_of(:epic_board_positions) }
+  end
+
+  describe 'validations' do
+    subject { build(:epic_board_position) }
+
+    specify { expect(subject).to be_valid }
+
+    it 'is valid with nil relative position' do
+      subject.relative_position = nil
+
+      expect(subject).to be_valid
+    end
+
+    it 'disallows a record with same epic and board' do
+      expect(build(:epic_board_position, epic: epic, epic_board: epic_board)).not_to be_valid
+    end
+  end
+
+  describe 'scopes' do
+    describe '.order_relative_position' do
+      let(:first) { epic_board_position }
+      let!(:second) { create(:epic_board_position, epic_board: epic_board, relative_position: RelativePositioning::START_POSITION + 7 ) }
+
+      it 'returns epic_board_positions in order' do
+        expect(described_class.order_relative_position).to eq([first, second])
+      end
+    end
+  end
+
+  context 'relative positioning' do
+    let_it_be(:positioning_group) { create(:group) }
+    let_it_be(:positioning_board) { create(:epic_board, group: positioning_group) }
+
+    it_behaves_like "a class that supports relative positioning" do
+      let(:factory) { :epic_board_position }
+      let(:default_params) { { parent: positioning_board } }
+    end
+  end
+end

ee/spec/models/boards/epic_board_spec.rb

@@ -6,6 +6,7 @@ RSpec.describe Boards::EpicBoard do
   describe 'associations' do
     it { is_expected.to belong_to(:group).required.inverse_of(:epic_boards) }
     it { is_expected.to have_many(:epic_board_labels).inverse_of(:epic_board) }
+    it { is_expected.to have_many(:epic_board_positions).inverse_of(:epic_board) }
   end
 
   describe 'validations' do