Add association between polls and budgets

app/models/budget.rb

@@ -21,6 +21,8 @@ class Budget < ActiveRecord::Base
   has_many :headings, through: :groups
   has_many :phases, class_name: Budget::Phase
 
+  has_one :poll
+
   before_validation :sanitize_descriptions
 
   after_create :generate_phases

app/models/poll.rb

@@ -23,6 +23,7 @@ class Poll < ActiveRecord::Base
 
   has_and_belongs_to_many :geozones
   belongs_to :author, -> { with_hidden }, class_name: "User", foreign_key: "author_id"
+  belongs_to :budget
 
   validates_translation :name, presence: true
   validate :date_range

db/migrate/20180604173248_add_budget_to_polls.rb

@@ -0,0 +1,5 @@
+class AddBudgetToPolls < ActiveRecord::Migration
+  def change
+    add_reference :polls, :budget, index: { unique: true }, foreign_key: true
+  end
+end

db/schema.rb

@@ -1129,8 +1129,10 @@ ActiveRecord::Schema.define(version: 20190205131722) do
     t.boolean  "stats_enabled",      default: false
     t.datetime "created_at"
     t.datetime "updated_at"
+    t.integer  "budget_id"
   end
 
+  add_index "polls", ["budget_id"], name: "index_polls_on_budget_id", unique: true, using: :btree
   add_index "polls", ["starts_at", "ends_at"], name: "index_polls_on_starts_at_and_ends_at", using: :btree
 
   create_table "progress_bar_translations", force: :cascade do |t|
@@ -1614,6 +1616,7 @@ ActiveRecord::Schema.define(version: 20190205131722) do
   add_foreign_key "poll_recounts", "poll_booth_assignments", column: "booth_assignment_id"
   add_foreign_key "poll_recounts", "poll_officer_assignments", column: "officer_assignment_id"
   add_foreign_key "poll_voters", "polls"
+  add_foreign_key "polls", "budgets"
   add_foreign_key "proposals", "communities"
   add_foreign_key "related_content_scores", "related_contents"
   add_foreign_key "related_content_scores", "users"