Migrates from ranked-model to positioning gem

app/models/blueprint.rb

@@ -33,9 +33,9 @@ def set_rooms
 
   def add_furniture(room, room_attributes)
     furnitures = room_attributes.fetch(:furnitures, {})
-    furnitures.each.with_index do |(furniture_kind, settings), slot|
+    furnitures.each.with_index do |(furniture_kind, settings), position|
       furniture = room.gizmos
-        .find_or_initialize_by(slot: slot)
+        .find_or_initialize_by(position: position)
       furniture
         .update!(settings: merge_non_empty(settings, furniture.settings),
           furniture_kind: furniture_kind)

app/models/furniture.rb

@@ -5,10 +5,9 @@
 # as JSON, so that {Furniture} can be tweaked and configured as appropriate for
 # it's particular use case.
 class Furniture < ApplicationRecord
-  include RankedModel
   location(parent: :room)
 
-  ranks :slot, with_same: [:room_id]
+  positioned on: :room
 
   belongs_to :room, inverse_of: :gizmos
   has_one :space, through: :room, inverse_of: :gizmos
@@ -17,9 +16,6 @@ class Furniture < ApplicationRecord
 
   attribute :settings, :json, default: -> { {} }
 
-  # The order in which {Furniture} is rendered in a Room. Lower is higher.
-  attribute :slot, :integer
-
   delegate :attributes=, to: :gizmo, prefix: true
 
   validates :furniture_kind, presence: true
@@ -28,6 +24,8 @@ class Furniture < ApplicationRecord
   # for a Marketplace
   has_encrypted :secrets, type: :json
 
+  scope :by_position, -> { order(position: :asc) }
+
   # Setting `secrets` to an empty hash after initialization will force consistent access for developers, rather than having to code around a potential nil value
   after_initialize do
     # The `RankedModel` gem uses

app/policies/furniture_policy.rb

@@ -25,7 +25,7 @@ def update?
   alias_method :destroy?, :update?
 
   def permitted_attributes(_params)
-    [:furniture_kind, :slot, gizmo_attributes: furniture_params]
+    [:furniture_kind, :position, gizmo_attributes: furniture_params]
   end
 
   def furniture_params

app/views/furnitures/_new.html.erb

@@ -1,7 +1,6 @@
 <div id="new_furniture">
   <h3><%= t('rooms.place_furniture_heading') %></h3>
   <%= form_with model: furniture.location do | form | %>
-    <%= form.hidden_field :slot, value: furniture.room.gizmos.count %>
     <%= render SelectComponent.new({
       choices: Furniture.registry.keys.map { |k| [k.to_s.titleize, k] },
       attribute: :furniture_kind,

app/views/rooms/_room.html.erb

@@ -1,9 +1,8 @@
 <%- if room.hero_image&.upload.present? %>
   <%= image_tag room.hero_image&.upload&.variant(resize_to_fill: Media::FULL_WIDTH_SHORT), class: "w-full" %>
 <%- end %>
-
 <div class="grow mx-auto w-full">
   <section id="furnitures">
-    <%= render room.gizmos.rank(:slot) %>
+    <%= render room.gizmos.by_position %>
   </section>
 </div>

app/views/rooms/edit.html.erb

@@ -16,7 +16,7 @@
     <h2>Gizmos</h2>
     <div id="furnitures">
       <% if room.gizmos.present? %>
-        <%= render room.gizmos.rank(:slot), editing: true %>
+        <%= render room.gizmos.by_position, editing: true %>
       <% else %>
         <p class="text-gray-500"><%= t('rooms.no_furniture_notice') %></p>
       <% end %>

db/migrate/20240530003329_renaming_furniture_slot_to_position.rb

@@ -0,0 +1,9 @@
+class RenamingFurnitureSlotToPosition < ActiveRecord::Migration[7.1]
+  def change
+    safety_assured do
+      rename_column :furnitures, :slot, :position
+      change_column_default :furnitures, :position, from: nil, to: 0
+      change_column_null :furnitures, :position, false
+    end
+  end
+end

db/migrate/20240530010707_add_position_index_to_furnitures.rb

@@ -0,0 +1,7 @@
+class AddPositionIndexToFurnitures < ActiveRecord::Migration[7.1]
+  disable_ddl_transaction!
+
+  def change
+    add_index :furnitures, [:room_id, :position], unique: true, algorithm: :concurrently
+  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[7.1].define(version: 2024_05_24_021224) do
+ActiveRecord::Schema[7.1].define(version: 2024_05_30_010707) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "pgcrypto"
   enable_extension "plpgsql"
@@ -94,13 +94,14 @@
   end
 
   create_table "furnitures", id: :uuid, default: -> { "gen_random_uuid()" }, force: :cascade do |t|
-    t.integer "slot"
+    t.integer "position", default: 0, null: false
     t.string "furniture_kind"
     t.jsonb "settings"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.uuid "room_id"
     t.text "secrets_ciphertext"
+    t.index ["room_id", "position"], name: "index_furnitures_on_room_id_and_position", unique: true
     t.index ["room_id"], name: "index_furnitures_on_room_id"
   end
 

spec/factories/furniture.rb

@@ -3,6 +3,5 @@
     room
     furniture_kind { "markdown_text_block" }
     settings { {content: "# Original Content"} }
-    slot_position { :last }
   end
 end

spec/factories/furniture/markdown_text_block.rb

@@ -7,6 +7,5 @@
     room
     furniture_kind { "markdown_text_block" }
     settings { {content: content} }
-    slot_position { :last }
   end
 end

spec/models/furniture_spec.rb

@@ -13,36 +13,6 @@
     end
   end
 
-  describe "#slot" do
-    let(:room) { create(:room) }
-    let(:placements) { create_list(:furniture, 3, room: room) }
-    # rubocop:disable RSpec/IndexedLet
-    let(:placement1) { placements[0] }
-    let(:placement2) { placements[1] }
-    let(:placement3) { placements[2] }
-    # rubocop:enable RSpec/IndexedLet
-
-    before {
-      placement1
-      placement2
-      placement3
-    }
-
-    it "inserts new placement between existing slots" do
-      new_placement = create(:furniture, room: room, slot_position: 1)
-      expect(placement1.slot_rank).to eq(0)
-      expect(new_placement.slot_rank).to eq(1)
-      expect(placement2.slot_rank).to eq(2)
-      expect(placement3.slot_rank).to eq(3)
-    end
-
-    it "gets placed last without an explicit position" do
-      new_placement = create(:furniture, room: room, slot_position: nil)
-      expect(new_placement).to be_valid
-      expect(new_placement.slot_position).to eq(3)
-    end
-  end
-
   describe "#setting" do
     class TestFurniture < described_class # rubocop:disable Lint/ConstantDefinitionInBlock, RSpec/LeakyConstantDeclaration
       setting :name, default: "some default value"

spec/requests/furnitures_controller_request_spec.rb

@@ -21,7 +21,6 @@
       perform_request
       placement = room.gizmos.last
       expect(placement.furniture).to be_a(MarkdownTextBlock)
-      expect(placement.slot).to be(0)
       expect(response).to redirect_to([space, room])
     end
   end