Add db table and model to track changes of iteration

* Add resourcee_iteration_events table
* Add ResourceIterationEvent model Reuse code from
ResourceMilestoneEvent model as a lot of fucntionality and logic
is very similar.

app/models/resource_iteration_event.rb

+# frozen_string_literal: true
+
+class ResourceIterationEvent < ResourceTimeboxEvent
+  belongs_to :iteration
+end

app/models/resource_milestone_event.rb

 # frozen_string_literal: true
 
-class ResourceMilestoneEvent < ResourceEvent
+class ResourceMilestoneEvent < ResourceTimeboxEvent
   include IgnorableColumns
-  include IssueResourceEvent
-  include MergeRequestResourceEvent
 
   belongs_to :milestone
 
-  validate :exactly_one_issuable
-
   scope :include_relations, -> { includes(:user, milestone: [:project, :group]) }
 
-  enum action: {
-    add: 1,
-    remove: 2
-  }
-
   # state is used for issue and merge request states.
   enum state: Issue.available_states.merge(MergeRequest.available_states)
 
   ignore_columns %i[reference reference_html cached_markdown_version], remove_with: '13.1', remove_after: '2020-06-22'
 
-  def self.issuable_attrs
-    %i(issue merge_request).freeze
-  end
-
   def milestone_title
     milestone&.title
   end
@@ -32,8 +19,4 @@ class ResourceMilestoneEvent < ResourceEvent
   def milestone_parent
     milestone&.parent
   end
-
-  def issuable
-    issue || merge_request
-  end
 end

app/models/resource_timebox_event.rb

+# frozen_string_literal: true
+
+class ResourceTimeboxEvent < ResourceEvent
+  self.abstract_class = true
+
+  include IssueResourceEvent
+  include MergeRequestResourceEvent
+
+  validate :exactly_one_issuable
+
+  enum action: {
+    add: 1,
+    remove: 2
+  }
+
+  def self.issuable_attrs
+    %i(issue merge_request).freeze
+  end
+
+  def issuable
+    issue || merge_request
+  end
+end

changelogs/unreleased/create-resource-iteration-events-table.yml

+---
+title: Add DB table and model to track changes of the iterations on issues
+merge_request: 37617
+author:
+type: added

db/migrate/20200722131241_create_resource_iteration_events_table.rb

+# frozen_string_literal: true
+
+class CreateResourceIterationEventsTable < ActiveRecord::Migration[6.0]
+  DOWNTIME = false
+
+  def change
+    create_table :resource_iteration_events do |t|
+      t.bigint :user_id, null: false, index: { name: 'index_resource_iteration_events_on_user_id' }
+      t.bigint :issue_id, null: true, index: { name: 'index_resource_iteration_events_on_issue_id' }
+      t.bigint :merge_request_id, null: true, index: { name: 'index_resource_iteration_events_on_merge_request_id' }
+      t.bigint :iteration_id, index: { name: 'index_resource_iteration_events_on_iteration_id' }
+      t.datetime_with_timezone :created_at, null: false
+      t.integer :action, limit: 2, null: false
+    end
+  end
+end

db/migrate/20200722132040_add_users_fk_to_resource_iteration_events_table.rb

+# frozen_string_literal: true
+
+class AddUsersFkToResourceIterationEventsTable < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def up
+    with_lock_retries do
+      add_foreign_key :resource_iteration_events, :users, column: :user_id, on_delete: :nullify # rubocop:disable Migration/AddConcurrentForeignKey
+    end
+  end
+
+  def down
+    with_lock_retries do
+      remove_foreign_key :resource_iteration_events, column: :user_id
+    end
+  end
+end

db/migrate/20200722132540_add_issues_fk_to_resource_iteration_events_table.rb

+# frozen_string_literal: true
+
+class AddIssuesFkToResourceIterationEventsTable < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def up
+    with_lock_retries do
+      add_foreign_key :resource_iteration_events, :issues, column: :issue_id, on_delete: :cascade # rubocop:disable Migration/AddConcurrentForeignKey
+    end
+  end
+
+  def down
+    with_lock_retries do
+      remove_foreign_key :resource_iteration_events, column: :issue_id
+    end
+  end
+end

db/migrate/20200722133040_add_merge_requests_fk_to_resource_iteration_events_table.rb

+# frozen_string_literal: true
+
+class AddMergeRequestsFkToResourceIterationEventsTable < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def up
+    with_lock_retries do
+      add_foreign_key :resource_iteration_events, :merge_requests, column: :merge_request_id, on_delete: :cascade # rubocop:disable Migration/AddConcurrentForeignKey
+    end
+  end
+
+  def down
+    with_lock_retries do
+      remove_foreign_key :resource_iteration_events, column: :merge_request_id
+    end
+  end
+end

db/migrate/20200722133540_add_iterations_fk_to_resource_iteration_events_table.rb

+# frozen_string_literal: true
+
+class AddIterationsFkToResourceIterationEventsTable < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def up
+    with_lock_retries do
+      add_foreign_key :resource_iteration_events, :sprints, column: :iteration_id, on_delete: :cascade # rubocop:disable Migration/AddConcurrentForeignKey
+    end
+  end
+
+  def down
+    with_lock_retries do
+      remove_foreign_key :resource_iteration_events, column: :iteration_id
+    end
+  end
+end

db/schema_migrations/20200722131241

+5fc97e904844b43a331246c68b1d0a879f683d5b36fab6cd024f417922259864
\ No newline at end of file

db/schema_migrations/20200722132040

+7b33a7f96ea02e3d5510cb6a6d75a9c753c1bd24c93d9995f91596d6b1a44592
\ No newline at end of file

db/schema_migrations/20200722132540

+543ebc8ab7fad96aeb5a8618bc954babb0eed1d252fe490aa6fab9b8e80ffbf1
\ No newline at end of file

db/schema_migrations/20200722133040

+4a6a322cf3f6e1622d3244f6faa99a1befcb8c626a8fea36b09d1910b770b88c
\ No newline at end of file

db/schema_migrations/20200722133540

+0307eb0f5082a5da84f5e94084b677d13e03f9cd5011efe3dc7e25645a00082d
\ No newline at end of file

db/structure.sql

@@ -15029,6 +15029,25 @@ CREATE SEQUENCE public.requirements_management_test_reports_id_seq
 
 ALTER SEQUENCE public.requirements_management_test_reports_id_seq OWNED BY public.requirements_management_test_reports.id;
 
+CREATE TABLE public.resource_iteration_events (
+    id bigint NOT NULL,
+    user_id bigint NOT NULL,
+    issue_id bigint,
+    merge_request_id bigint,
+    iteration_id bigint,
+    created_at timestamp with time zone NOT NULL,
+    action smallint NOT NULL
+);
+
+CREATE SEQUENCE public.resource_iteration_events_id_seq
+    START WITH 1
+    INCREMENT BY 1
+    NO MINVALUE
+    NO MAXVALUE
+    CACHE 1;
+
+ALTER SEQUENCE public.resource_iteration_events_id_seq OWNED BY public.resource_iteration_events.id;
+
 CREATE TABLE public.resource_label_events (
     id bigint NOT NULL,
     action integer NOT NULL,
@@ -17176,6 +17195,8 @@ ALTER TABLE ONLY public.requirements ALTER COLUMN id SET DEFAULT nextval('public
 
 ALTER TABLE ONLY public.requirements_management_test_reports ALTER COLUMN id SET DEFAULT nextval('public.requirements_management_test_reports_id_seq'::regclass);
 
+ALTER TABLE ONLY public.resource_iteration_events ALTER COLUMN id SET DEFAULT nextval('public.resource_iteration_events_id_seq'::regclass);
+
 ALTER TABLE ONLY public.resource_label_events ALTER COLUMN id SET DEFAULT nextval('public.resource_label_events_id_seq'::regclass);
 
 ALTER TABLE ONLY public.resource_milestone_events ALTER COLUMN id SET DEFAULT nextval('public.resource_milestone_events_id_seq'::regclass);
@@ -18396,6 +18417,9 @@ ALTER TABLE ONLY public.requirements_management_test_reports
 ALTER TABLE ONLY public.requirements
     ADD CONSTRAINT requirements_pkey PRIMARY KEY (id);
 
+ALTER TABLE ONLY public.resource_iteration_events
+    ADD CONSTRAINT resource_iteration_events_pkey PRIMARY KEY (id);
+
 ALTER TABLE ONLY public.resource_label_events
     ADD CONSTRAINT resource_label_events_pkey PRIMARY KEY (id);
 
@@ -20476,6 +20500,14 @@ CREATE INDEX index_requirements_on_title_trigram ON public.requirements USING gi
 
 CREATE INDEX index_requirements_on_updated_at ON public.requirements USING btree (updated_at);
 
+CREATE INDEX index_resource_iteration_events_on_issue_id ON public.resource_iteration_events USING btree (issue_id);
+
+CREATE INDEX index_resource_iteration_events_on_iteration_id ON public.resource_iteration_events USING btree (iteration_id);
+
+CREATE INDEX index_resource_iteration_events_on_merge_request_id ON public.resource_iteration_events USING btree (merge_request_id);
+
+CREATE INDEX index_resource_iteration_events_on_user_id ON public.resource_iteration_events USING btree (user_id);
+
 CREATE INDEX index_resource_label_events_issue_id_label_id_action ON public.resource_label_events USING btree (issue_id, label_id, action);
 
 CREATE INDEX index_resource_label_events_on_epic_id ON public.resource_label_events USING btree (epic_id);
@@ -22225,6 +22257,9 @@ ALTER TABLE ONLY public.security_scans
 ALTER TABLE ONLY public.merge_request_diff_files
     ADD CONSTRAINT fk_rails_501aa0a391 FOREIGN KEY (merge_request_diff_id) REFERENCES public.merge_request_diffs(id) ON DELETE CASCADE;
 
+ALTER TABLE ONLY public.resource_iteration_events
+    ADD CONSTRAINT fk_rails_501fa15d69 FOREIGN KEY (user_id) REFERENCES public.users(id) ON DELETE SET NULL;
+
 ALTER TABLE ONLY public.status_page_settings
     ADD CONSTRAINT fk_rails_506e5ba391 FOREIGN KEY (project_id) REFERENCES public.projects(id) ON DELETE CASCADE;
 
@@ -22363,6 +22398,9 @@ ALTER TABLE ONLY public.web_hook_logs
 ALTER TABLE ONLY public.jira_imports
     ADD CONSTRAINT fk_rails_675d38c03b FOREIGN KEY (label_id) REFERENCES public.labels(id) ON DELETE SET NULL;
 
+ALTER TABLE ONLY public.resource_iteration_events
+    ADD CONSTRAINT fk_rails_6830c13ac1 FOREIGN KEY (merge_request_id) REFERENCES public.merge_requests(id) ON DELETE CASCADE;
+
 ALTER TABLE ONLY public.geo_hashed_storage_migrated_events
     ADD CONSTRAINT fk_rails_687ed7d7c5 FOREIGN KEY (project_id) REFERENCES public.projects(id) ON DELETE CASCADE;
 
@@ -22660,6 +22698,9 @@ ALTER TABLE ONLY public.x509_commit_signatures
 ALTER TABLE ONLY public.ci_build_trace_sections
     ADD CONSTRAINT fk_rails_ab7c104e26 FOREIGN KEY (project_id) REFERENCES public.projects(id) ON DELETE CASCADE;
 
+ALTER TABLE ONLY public.resource_iteration_events
+    ADD CONSTRAINT fk_rails_abf5d4affa FOREIGN KEY (issue_id) REFERENCES public.issues(id) ON DELETE CASCADE;
+
 ALTER TABLE ONLY public.clusters
     ADD CONSTRAINT fk_rails_ac3a663d79 FOREIGN KEY (user_id) REFERENCES public.users(id) ON DELETE SET NULL;
 
@@ -22816,6 +22857,9 @@ ALTER TABLE ONLY public.issue_tracker_data
 ALTER TABLE ONLY public.resource_milestone_events
     ADD CONSTRAINT fk_rails_cedf8cce4d FOREIGN KEY (user_id) REFERENCES public.users(id) ON DELETE SET NULL;
 
+ALTER TABLE ONLY public.resource_iteration_events
+    ADD CONSTRAINT fk_rails_cee126f66c FOREIGN KEY (iteration_id) REFERENCES public.sprints(id) ON DELETE CASCADE;
+
 ALTER TABLE ONLY public.epic_metrics
     ADD CONSTRAINT fk_rails_d071904753 FOREIGN KEY (epic_id) REFERENCES public.epics(id) ON DELETE CASCADE;
 

spec/db/schema_spec.rb

@@ -165,6 +165,9 @@ RSpec.describe 'Database schema' do
 
   context 'for enums' do
     ApplicationRecord.descendants.each do |model|
+      # skip model if it is an abstract class as it would not have an associated DB table
+      next if model.abstract_class?
+
       describe model do
         let(:ignored_enums) { ignored_limit_enums(model.name) }
         let(:enums) { model.defined_enums.keys - ignored_enums }

spec/factories/resource_iteration_event.rb

+# frozen_string_literal: true
+
+FactoryBot.define do
+  factory :resource_iteration_event do
+    issue { merge_request.nil? ? create(:issue) : nil }
+    merge_request { nil }
+    iteration
+    action { :add }
+    user { issue&.author || merge_request&.author || create(:user) }
+  end
+end

spec/models/resource_iteration_event_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe ResourceIterationEvent, type: :model do
+  it_behaves_like 'a resource event'
+  it_behaves_like 'a resource event for issues'
+  it_behaves_like 'a resource event for merge requests'
+
+  it_behaves_like 'having unique enum values'
+  it_behaves_like 'timebox resource event validations'
+  it_behaves_like 'timebox resource event actions'
+
+  describe 'associations' do
+    it { is_expected.to belong_to(:iteration) }
+  end
+end

spec/models/resource_milestone_event_spec.rb

@@ -8,77 +8,14 @@ RSpec.describe ResourceMilestoneEvent, type: :model do
   it_behaves_like 'a resource event for merge requests'
 
   it_behaves_like 'having unique enum values'
+  it_behaves_like 'timebox resource event validations'
+  it_behaves_like 'timebox resource event states'
+  it_behaves_like 'timebox resource event actions'
 
   describe 'associations' do
     it { is_expected.to belong_to(:milestone) }
   end
 
-  describe 'validations' do
-    context 'when issue and merge_request are both nil' do
-      subject { build(described_class.name.underscore.to_sym, issue: nil, merge_request: nil) }
-
-      it { is_expected.not_to be_valid }
-    end
-
-    context 'when issue and merge_request are both set' do
-      subject { build(described_class.name.underscore.to_sym, issue: build(:issue), merge_request: build(:merge_request)) }
-
-      it { is_expected.not_to be_valid }
-    end
-
-    context 'when issue is set' do
-      subject { create(described_class.name.underscore.to_sym, issue: create(:issue), merge_request: nil) }
-
-      it { is_expected.to be_valid }
-    end
-
-    context 'when merge_request is set' do
-      subject { create(described_class.name.underscore.to_sym, issue: nil, merge_request: create(:merge_request)) }
-
-      it { is_expected.to be_valid }
-    end
-  end
-
-  describe 'states' do
-    [Issue, MergeRequest].each do |klass|
-      klass.available_states.each do |state|
-        it "supports state #{state.first} for #{klass.name.underscore}" do
-          model = create(klass.name.underscore, state: state[0])
-          key = model.class.name.underscore
-          event = build(described_class.name.underscore.to_sym, key => model, state: model.state)
-
-          expect(event.state).to eq(state[0])
-        end
-      end
-    end
-  end
-
-  shared_examples 'a milestone action queryable resource event' do |expected_results_for_actions|
-    [Issue, MergeRequest].each do |klass|
-      expected_results_for_actions.each do |action, expected_result|
-        it "is #{expected_result} for action #{action} on #{klass.name.underscore}" do
-          model = create(klass.name.underscore)
-          key = model.class.name.underscore
-          event = build(described_class.name.underscore.to_sym, key => model, action: action)
-
-          expect(event.send(query_method)).to eq(expected_result)
-        end
-      end
-    end
-  end
-
-  describe '#added?' do
-    it_behaves_like 'a milestone action queryable resource event', { add: true, remove: false } do
-      let(:query_method) { :add? }
-    end
-  end
-
-  describe '#removed?' do
-    it_behaves_like 'a milestone action queryable resource event', { add: false, remove: true } do
-      let(:query_method) { :remove? }
-    end
-  end
-
   describe '#milestone_title' do
     let(:milestone) { create(:milestone, title: 'v2.3') }
     let(:event) { create(:resource_milestone_event, milestone: milestone) }

spec/support/shared_examples/models/resource_timebox_event_shared_examples.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.shared_examples 'timebox resource event validations' do
+  describe 'validations' do
+    context 'when issue and merge_request are both nil' do
+      subject { build(described_class.name.underscore.to_sym, issue: nil, merge_request: nil) }
+
+      it { is_expected.not_to be_valid }
+    end
+
+    context 'when issue and merge_request are both set' do
+      subject { build(described_class.name.underscore.to_sym, issue: build(:issue), merge_request: build(:merge_request)) }
+
+      it { is_expected.not_to be_valid }
+    end
+
+    context 'when issue is set' do
+      subject { create(described_class.name.underscore.to_sym, issue: create(:issue), merge_request: nil) }
+
+      it { is_expected.to be_valid }
+    end
+
+    context 'when merge_request is set' do
+      subject { create(described_class.name.underscore.to_sym, issue: nil, merge_request: create(:merge_request)) }
+
+      it { is_expected.to be_valid }
+    end
+  end
+end
+
+RSpec.shared_examples 'timebox resource event states' do
+  describe 'states' do
+    [Issue, MergeRequest].each do |klass|
+      klass.available_states.each do |state|
+        it "supports state #{state.first} for #{klass.name.underscore}" do
+          model = create(klass.name.underscore, state: state[0])
+          key = model.class.name.underscore
+          event = build(described_class.name.underscore.to_sym, key => model, state: model.state)
+
+          expect(event.state).to eq(state[0])
+        end
+      end
+    end
+  end
+end
+
+RSpec.shared_examples 'queryable timebox action resource event' do |expected_results_for_actions|
+  [Issue, MergeRequest].each do |klass|
+    expected_results_for_actions.each do |action, expected_result|
+      it "is #{expected_result} for action #{action} on #{klass.name.underscore}" do
+        model = build(klass.name.underscore)
+        key = model.class.name.underscore
+        event = build(described_class.name.underscore.to_sym, key => model, action: action)
+
+        expect(event.send(query_method)).to eq(expected_result)
+      end
+    end
+  end
+end
+
+RSpec.shared_examples 'timebox resource event actions' do
+  describe '#added?' do
+    it_behaves_like 'queryable timebox action resource event', { add: true, remove: false } do
+      let(:query_method) { :add? }
+    end
+  end
+
+  describe '#removed?' do
+    it_behaves_like 'queryable timebox action resource event', { add: false, remove: true } do
+      let(:query_method) { :remove? }
+    end
+  end
+end