Add models to represent "Collections" (#36977)

app/models/collection.rb

@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+# == Schema Information
+#
+# Table name: collections
+#
+#  id                       :bigint(8)        not null, primary key
+#  description              :text             not null
+#  discoverable             :boolean          not null
+#  local                    :boolean          not null
+#  name                     :string           not null
+#  original_number_of_items :integer
+#  sensitive                :boolean          not null
+#  uri                      :string
+#  created_at               :datetime         not null
+#  updated_at               :datetime         not null
+#  account_id               :bigint(8)        not null
+#  tag_id                   :bigint(8)
+#
+class Collection < ApplicationRecord
+  MAX_ITEMS = 25
+
+  belongs_to :account
+  belongs_to :tag, optional: true
+
+  has_many :collection_items, dependent: :delete_all
+
+  validates :name, presence: true
+  validates :description, presence: true
+  validates :uri, presence: true, if: :remote?
+  validates :original_number_of_items,
+            presence: true,
+            numericality: { greater_than_or_equal: 0 },
+            if: :remote?
+  validate :tag_is_usable
+  validate :items_do_not_exceed_limit
+
+  def remote?
+    !local?
+  end
+
+  private
+
+  def tag_is_usable
+    return if tag.blank?
+
+    errors.add(:tag, :unusable) unless tag.usable?
+  end
+
+  def items_do_not_exceed_limit
+    errors.add(:collection_items, :too_many, count: MAX_ITEMS) if collection_items.size > MAX_ITEMS
+  end
+end

app/models/collection_item.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+# == Schema Information
+#
+# Table name: collection_items
+#
+#  id                        :bigint(8)        not null, primary key
+#  activity_uri              :string
+#  approval_last_verified_at :datetime
+#  approval_uri              :string
+#  object_uri                :string
+#  position                  :integer          default(1), not null
+#  state                     :integer          default("pending"), not null
+#  created_at                :datetime         not null
+#  updated_at                :datetime         not null
+#  account_id                :bigint(8)
+#  collection_id             :bigint(8)        not null
+#
+class CollectionItem < ApplicationRecord
+  belongs_to :collection
+  belongs_to :account, optional: true
+
+  enum :state,
+       { pending: 0, accepted: 1, rejected: 2, revoked: 3 },
+       validate: true
+
+  delegate :local?, :remote?, to: :collection
+
+  validates :position, numericality: { only_integer: true, greater_than: 0 }
+  validates :activity_uri, presence: true, if: :local_item_with_remote_account?
+  validates :approval_uri, absence: true, unless: :local?
+  validates :account, presence: true, if: :accepted?
+  validates :object_uri, presence: true, if: -> { account.nil? }
+
+  scope :ordered, -> { order(position: :asc) }
+
+  def local_item_with_remote_account?
+    local? && account&.remote?
+  end
+end

app/models/concerns/account/associations.rb

@@ -13,6 +13,8 @@ module Account::Associations
         has_many :account_warnings
         has_many :aliases, class_name: 'AccountAlias'
         has_many :bookmarks
+        has_many :collections
+        has_many :collection_items
         has_many :conversations, class_name: 'AccountConversation'
         has_many :custom_filters
         has_many :favourites

config/locales/activerecord.en.yml

@@ -32,6 +32,12 @@ en:
           attributes:
             url:
               invalid: is not a valid URL
+        collection:
+          attributes:
+            collection_items:
+              too_many: are too many, no more than %{count} are allowed
+            tag:
+              unusable: may not be used
         doorkeeper/application:
           attributes:
             website:

db/migrate/20251118115657_create_collections.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+class CreateCollections < ActiveRecord::Migration[8.0]
+  def change
+    create_table :collections do |t|
+      t.references :account, null: false, foreign_key: true
+      t.string :name, null: false
+      t.text :description, null: false
+      t.string :uri
+      t.boolean :local, null: false # rubocop:disable Rails/ThreeStateBooleanColumn
+      t.boolean :sensitive, null: false # rubocop:disable Rails/ThreeStateBooleanColumn
+      t.boolean :discoverable, null: false # rubocop:disable Rails/ThreeStateBooleanColumn
+      t.references :tag, foreign_key: true
+      t.integer :original_number_of_items
+
+      t.timestamps
+    end
+  end
+end

db/migrate/20251119093332_create_collection_items.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+class CreateCollectionItems < ActiveRecord::Migration[8.0]
+  def change
+    create_table :collection_items do |t|
+      t.references :collection, null: false, foreign_key: { on_delete: :cascade }
+      t.references :account, foreign_key: true
+      t.integer :position, null: false, default: 1
+      t.string :object_uri, index: { unique: true, where: 'activity_uri IS NOT NULL' }
+      t.string :approval_uri, index: { unique: true, where: 'approval_uri IS NOT NULL' }
+      t.string :activity_uri
+      t.datetime :approval_last_verified_at
+      t.integer :state, null: false, default: 0
+
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2025_10_23_210145) do
+ActiveRecord::Schema[8.0].define(version: 2025_11_19_093332) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "pg_catalog.plpgsql"
 
@@ -351,6 +351,39 @@ ActiveRecord::Schema[8.0].define(version: 2025_10_23_210145) do
     t.index ["reference_account_id"], name: "index_canonical_email_blocks_on_reference_account_id"
   end
 
+  create_table "collection_items", force: :cascade do |t|
+    t.bigint "collection_id", null: false
+    t.bigint "account_id"
+    t.integer "position", default: 1, null: false
+    t.string "object_uri"
+    t.string "approval_uri"
+    t.string "activity_uri"
+    t.datetime "approval_last_verified_at"
+    t.integer "state", default: 0, null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["account_id"], name: "index_collection_items_on_account_id"
+    t.index ["approval_uri"], name: "index_collection_items_on_approval_uri", unique: true, where: "(approval_uri IS NOT NULL)"
+    t.index ["collection_id"], name: "index_collection_items_on_collection_id"
+    t.index ["object_uri"], name: "index_collection_items_on_object_uri", unique: true, where: "(activity_uri IS NOT NULL)"
+  end
+
+  create_table "collections", force: :cascade do |t|
+    t.bigint "account_id", null: false
+    t.string "name", null: false
+    t.text "description", null: false
+    t.string "uri"
+    t.boolean "local", null: false
+    t.boolean "sensitive", null: false
+    t.boolean "discoverable", null: false
+    t.bigint "tag_id"
+    t.integer "original_number_of_items"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["account_id"], name: "index_collections_on_account_id"
+    t.index ["tag_id"], name: "index_collections_on_tag_id"
+  end
+
   create_table "conversation_mutes", force: :cascade do |t|
     t.bigint "conversation_id", null: false
     t.bigint "account_id", null: false
@@ -1386,6 +1419,10 @@ ActiveRecord::Schema[8.0].define(version: 2025_10_23_210145) do
   add_foreign_key "bulk_import_rows", "bulk_imports", on_delete: :cascade
   add_foreign_key "bulk_imports", "accounts", on_delete: :cascade
   add_foreign_key "canonical_email_blocks", "accounts", column: "reference_account_id", on_delete: :cascade
+  add_foreign_key "collection_items", "accounts"
+  add_foreign_key "collection_items", "collections", on_delete: :cascade
+  add_foreign_key "collections", "accounts"
+  add_foreign_key "collections", "tags"
   add_foreign_key "conversation_mutes", "accounts", name: "fk_225b4212bb", on_delete: :cascade
   add_foreign_key "conversation_mutes", "conversations", on_delete: :cascade
   add_foreign_key "custom_filter_keywords", "custom_filters", on_delete: :cascade

spec/fabricators/account_fabricator.rb

@@ -17,3 +17,7 @@ Fabricator(:account) do
   discoverable        true
   indexable           true
 end
+
+Fabricator(:remote_account, from: :account) do
+  domain 'example.com'
+end

spec/fabricators/collection_fabricator.rb

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+Fabricator(:collection) do
+  account      { Fabricate.build(:account) }
+  name         { sequence(:name) { |i| "Collection ##{i}" } }
+  description  'People to follow'
+  local        true
+  sensitive    false
+  discoverable true
+end

spec/fabricators/collection_item_fabricator.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+Fabricator(:collection_item) do
+  collection                { Fabricate.build(:collection) }
+  account                   { Fabricate.build(:account) }
+  position                  1
+  state                     :accepted
+end
+
+Fabricator(:unverified_remote_collection_item, from: :collection_item) do
+  account      nil
+  state        :pending
+  object_uri   { Fabricate.build(:remote_account).uri }
+  approval_uri { sequence(:uri) { |i| "https://example.com/authorizations/#{i}" } }
+end

spec/models/collection_item_spec.rb

@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe CollectionItem do
+  describe 'Validations' do
+    subject { Fabricate.build(:collection_item) }
+
+    it { is_expected.to define_enum_for(:state) }
+
+    it { is_expected.to validate_numericality_of(:position).only_integer.is_greater_than(0) }
+
+    context 'when account inclusion is accepted' do
+      subject { Fabricate.build(:collection_item, state: :accepted) }
+
+      it { is_expected.to validate_presence_of(:account) }
+    end
+
+    context 'when item is local and account is remote' do
+      subject { Fabricate.build(:collection_item, account: remote_account) }
+
+      let(:remote_account) { Fabricate.build(:remote_account) }
+
+      it { is_expected.to validate_presence_of(:activity_uri) }
+    end
+
+    context 'when item is not local' do
+      subject { Fabricate.build(:collection_item, collection: remote_collection) }
+
+      let(:remote_collection) { Fabricate.build(:collection, local: false) }
+
+      it { is_expected.to validate_absence_of(:approval_uri) }
+    end
+
+    context 'when account is not present' do
+      subject { Fabricate.build(:unverified_remote_collection_item) }
+
+      it { is_expected.to validate_presence_of(:object_uri) }
+    end
+  end
+end

spec/models/collection_spec.rb

@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Collection do
+  describe 'Validations' do
+    subject { Fabricate.build :collection }
+
+    it { is_expected.to validate_presence_of(:name) }
+
+    it { is_expected.to validate_presence_of(:description) }
+
+    context 'when collection is remote' do
+      subject { Fabricate.build :collection, local: false }
+
+      it { is_expected.to validate_presence_of(:uri) }
+
+      it { is_expected.to validate_presence_of(:original_number_of_items) }
+    end
+
+    context 'when using a hashtag as category' do
+      subject { Fabricate.build(:collection, tag:) }
+
+      context 'when hashtag is usable' do
+        let(:tag) { Fabricate.build(:tag) }
+
+        it { is_expected.to be_valid }
+      end
+
+      context 'when hashtag is not usable' do
+        let(:tag) { Fabricate.build(:tag, usable: false) }
+
+        it { is_expected.to_not be_valid }
+      end
+    end
+
+    context 'when there are more items than allowed' do
+      subject { Fabricate.build(:collection, collection_items:) }
+
+      let(:collection_items) { Fabricate.build_times(described_class::MAX_ITEMS + 1, :collection_item, collection: nil) }
+
+      it { is_expected.to_not be_valid }
+    end
+  end
+end