Added Requirement model

This is a basic model to represent Requirement resource.

changelogs/unreleased/requirements-model.yml

+---
+title: Add migration for Requirement model
+merge_request: 26097
+author:
+type: added

db/migrate/20200226100614_create_requirements.rb

+# frozen_string_literal: true
+
+class CreateRequirements < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def change
+    create_table :requirements do |t|
+      t.integer :state, limit: 2, default: 1, null: false
+      t.integer :iid, null: false
+      t.references :project, index: true, foreign_key: { on_delete: :cascade }
+      t.references :group, index: true, foreign_key: { to_table: :namespaces, on_delete: :cascade }
+      t.references :author, index: true, foreign_key: { to_table: :users, on_delete: :nullify }
+      t.timestamps_with_timezone null: false
+      t.string :title, limit: 255, null: false
+      t.text :title_html
+
+      t.index :title
+      t.index :state
+      t.index :created_at
+      t.index :updated_at
+      t.index %w(project_id iid), name: 'index_requirements_on_project_id_and_iid', where: 'project_id IS NOT NULL', unique: true, using: :btree
+      t.index %w(group_id iid), name: 'index_requirements_on_group_id_and_iid', where: 'group_id IS NOT NULL', unique: true, using: :btree
+    end
+  end
+end

db/schema.rb

@@ -3722,6 +3722,27 @@ ActiveRecord::Schema.define(version: 2020_02_27_165129) do
     t.index ["project_id", "programming_language_id"], name: "index_repository_languages_on_project_and_languages_id", unique: true
   end
 
+  create_table "requirements", force: :cascade do |t|
+    t.integer "state", limit: 2, default: 1, null: false
+    t.integer "iid", null: false
+    t.bigint "project_id"
+    t.bigint "group_id"
+    t.bigint "author_id"
+    t.datetime_with_timezone "created_at", null: false
+    t.datetime_with_timezone "updated_at", null: false
+    t.string "title", limit: 255, null: false
+    t.text "title_html"
+    t.index ["author_id"], name: "index_requirements_on_author_id"
+    t.index ["created_at"], name: "index_requirements_on_created_at"
+    t.index ["group_id", "iid"], name: "index_requirements_on_group_id_and_iid", unique: true, where: "(group_id IS NOT NULL)"
+    t.index ["group_id"], name: "index_requirements_on_group_id"
+    t.index ["project_id", "iid"], name: "index_requirements_on_project_id_and_iid", unique: true, where: "(project_id IS NOT NULL)"
+    t.index ["project_id"], name: "index_requirements_on_project_id"
+    t.index ["state"], name: "index_requirements_on_state"
+    t.index ["title"], name: "index_requirements_on_title"
+    t.index ["updated_at"], name: "index_requirements_on_updated_at"
+  end
+
   create_table "resource_label_events", force: :cascade do |t|
     t.integer "action", null: false
     t.integer "issue_id"
@@ -4996,6 +5017,9 @@ ActiveRecord::Schema.define(version: 2020_02_27_165129) do
   add_foreign_key "releases", "users", column: "author_id", name: "fk_8e4456f90f", on_delete: :nullify
   add_foreign_key "remote_mirrors", "projects", name: "fk_43a9aa4ca8", on_delete: :cascade
   add_foreign_key "repository_languages", "projects", on_delete: :cascade
+  add_foreign_key "requirements", "namespaces", column: "group_id", on_delete: :cascade
+  add_foreign_key "requirements", "projects", on_delete: :cascade
+  add_foreign_key "requirements", "users", column: "author_id", on_delete: :nullify
   add_foreign_key "resource_label_events", "epics", on_delete: :cascade
   add_foreign_key "resource_label_events", "issues", on_delete: :cascade
   add_foreign_key "resource_label_events", "labels", on_delete: :nullify

ee/app/models/ee/group.rb

@@ -17,6 +17,7 @@ module EE
       add_authentication_token_field :saml_discovery_token, unique: false, token_generator: -> { Devise.friendly_token(8) }
 
       has_many :epics
+      has_many :requirements
 
       has_one :saml_provider
       has_many :ip_restrictions, autosave: true

ee/app/models/ee/project.rb

@@ -59,6 +59,7 @@ module EE
       has_many :audit_events, as: :entity
       has_many :designs, inverse_of: :project, class_name: 'DesignManagement::Design'
       has_many :path_locks
+      has_many :requirements
 
       # the rationale behind vulnerabilities and vulnerability_findings can be found here:
       # https://gitlab.com/gitlab-org/gitlab/issues/10252#terminology

ee/app/models/ee/user.rb

@@ -32,6 +32,7 @@ module EE
 
       has_many :reviews,                  foreign_key: :author_id, inverse_of: :author
       has_many :epics,                    foreign_key: :author_id
+      has_many :requirements,             foreign_key: :author_id
       has_many :assigned_epics,           foreign_key: :assignee_id, class_name: "Epic"
       has_many :path_locks,               dependent: :destroy # rubocop: disable Cop/ActiveRecordDependent
       has_many :vulnerability_feedback, foreign_key: :author_id, class_name: 'Vulnerabilities::Feedback'

ee/app/models/requirement.rb

+# frozen_string_literal: true
+
+class Requirement < ApplicationRecord
+  include CacheMarkdownField
+
+  cache_markdown_field :title, pipeline: :single_line
+
+  belongs_to :author, class_name: 'User'
+  belongs_to :project
+  belongs_to :group
+
+  validates :author, :project, :title, presence: true
+
+  # For MVC, we allow only project-scoped requirements,
+  # but we already know that in the next iteration we will
+  # need also group-scoped requirements
+  validates :group, absence: true
+
+  validates :title, length: { maximum: Issuable::TITLE_LENGTH_MAX }
+  validates :title_html, length: { maximum: Issuable::TITLE_HTML_LENGTH_MAX }, allow_blank: true
+
+  enum state: { opened: 1, archived: 2 }
+
+  # In the next iteration we will support also group-level requirements
+  # so it use resource_parent instead of project directly
+  def resource_parent
+    project
+  end
+end

ee/app/services/ee/users/migrate_to_ghost_user_service.rb

@@ -7,6 +7,7 @@ module EE
 
       def migrate_records
         migrate_epics
+        migrate_requirements
         migrate_vulnerabilities_feedback
         migrate_reviews
         super
@@ -19,6 +20,10 @@ module EE
       end
       # rubocop: enable CodeReuse/ActiveRecord
 
+      def migrate_requirements
+        user.requirements.update_all(author_id: ghost_user.id)
+      end
+
       def migrate_vulnerabilities_feedback
         user.vulnerability_feedback.update_all(author_id: ghost_user.id)
         user.commented_vulnerability_feedback.update_all(comment_author_id: ghost_user.id)

ee/spec/factories/requirements.rb

+
+# frozen_string_literal: true
+
+FactoryBot.define do
+  factory :requirement do
+    project
+    author
+    title { generate(:title) }
+    title_html { "<h2>#{title}</h2>" }
+  end
+end

ee/spec/models/requirement_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Requirement do
+  let_it_be(:user) { create(:user) }
+  let_it_be(:group) { create(:group) }
+  let_it_be(:project) { create(:project, group: group) }
+
+  describe 'associations' do
+    subject { build(:requirement) }
+
+    it { is_expected.to belong_to(:author).class_name('User') }
+    it { is_expected.to belong_to(:group) }
+    it { is_expected.to belong_to(:project) }
+  end
+
+  describe 'validations' do
+    subject { build(:requirement) }
+
+    it { is_expected.to validate_presence_of(:project) }
+    it { is_expected.to validate_presence_of(:author) }
+    it { is_expected.to validate_presence_of(:title) }
+    it { is_expected.to validate_absence_of(:group) }
+
+    it { is_expected.to validate_length_of(:title).is_at_most(::Issuable::TITLE_LENGTH_MAX) }
+    it { is_expected.to validate_length_of(:title_html).is_at_most(::Issuable::TITLE_HTML_LENGTH_MAX) }
+  end
+end