Migrate registration policies from JSONB to ActiveRecord (#11238)

Registration policies and their buckets were stored as JSONB blobs on
events/event_proposals, making bucket_key references in signups,
signup_requests, and signup_ranked_choices plain strings with no
referential integrity (the cause of #11229). This moves them into real
registration_policies/registration_policy_buckets tables.

Key design points:
- Buckets are updated in place on edit (matched by key, never renamed)
  rather than replaced wholesale, so row identity is stable for
  anything that didn't change -- deliberately compatible with a future
  bucket_key -> FK conversion on signups (still deferred).
- External API (GraphQL field names, Liquid) is unchanged: anything/
  not_counted are preserved as aliases over the new flex/counted
  columns, since nothing in the frontend actually shows a bucket's key
  to users, only its name.
- No accepts_nested_attributes_for, attributes= override, or ==
  override -- this app doesn't use Rails form helpers, and explicit
  named methods (build_from_hash, equivalent_to?) are easier to trace
  than hooking into Rails' implicit machinery.
- EventProposal is migrated in this same pass; a shared
  HasRegistrationPolicy concern unifies what was previously duplicated
  apply-the-change logic between Event and EventProposal's write paths.

Verified against a full copy of production data end to end, which
caught a few real bugs before they went anywhere near a shared
database: an id leak in RegistrationPolicy#as_json that corrupted
detached-policy comparisons, a stale association cache in bucket sync
that let a destroyed bucket reappear in an audit log, a missing
registration_policy default in AcceptEventProposalService now that the
column is NOT NULL, and a dependent: option conflict that blocked
destroying an event that owned its own policy.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: nbudin

.rubocop_todo.yml

@@ -36,6 +36,8 @@ GraphQL/UnnecessaryArgumentCamelize:
 Lint/MissingCopEnableDirective:
   Exclude:
     - 'app/graphql/types/mutation_type.rb'
+    - 'test/graphql/mutations/update_event_proposal_test.rb'
+    - 'test/graphql/mutations/update_event_test.rb'
 
 # Offense count: 1
 Lint/NoReturnInBeginEndBlocks:
@@ -49,7 +51,19 @@ Metrics/BlockLength:
   Exclude:
     - 'config/environments/production.rb'
     - 'config/initializers/doorkeeper.rb'
+    - 'test/liquid_drops/convention_drop_test.rb'
+    - 'test/models/event_test.rb'
+    - 'test/models/registration_policy_bucket_test.rb'
+    - 'test/models/registration_policy_test.rb'
     - 'test/presenters/signup_count_presenter_test.rb'
+    - 'test/services/create_signup_request_service_test.rb'
+    - 'test/services/create_team_member_service_test.rb'
+    - 'test/services/event_change_registration_policy_service_test.rb'
+    - 'test/services/event_signup_service_test.rb'
+    - 'test/services/event_vacancy_fill_service_test.rb'
+    - 'test/services/event_withdraw_service_test.rb'
+    - 'test/services/execute_ranked_choice_signup_round_service_test.rb'
+    - 'test/services/execute_ranked_choice_signup_service_test.rb'
 
 # Offense count: 7
 # Configuration parameters: CountComments, Max, CountAsOne.
@@ -60,8 +74,20 @@ Metrics/ClassLength:
     - 'app/graphql/types/ability_type.rb'
     - 'app/graphql/types/mutation_type.rb'
     - 'app/graphql/types/query_type.rb'
+    - 'app/models/convention.rb'
+    - 'app/models/event.rb'
+    - 'app/models/registration_policy.rb'
     - 'app/presenters/signup_count_presenter.rb'
+    - 'app/services/event_change_registration_policy_service.rb'
+    - 'app/services/execute_ranked_choice_signup_round_service.rb'
+    - 'test/models/registration_policy_bucket_test.rb'
+    - 'test/models/registration_policy_test.rb'
     - 'test/presenters/signup_count_presenter_test.rb'
+    - 'test/services/create_signup_request_service_test.rb'
+    - 'test/services/create_team_member_service_test.rb'
+    - 'test/services/event_change_registration_policy_service_test.rb'
+    - 'test/services/event_vacancy_fill_service_test.rb'
+    - 'test/services/event_withdraw_service_test.rb'
 
 # Offense count: 1
 # Configuration parameters: Max.
@@ -104,6 +130,7 @@ Rails/HasAndBelongsToMany:
 
 Rails/HasManyOrHasOneDependent:
   Exclude:
+    - 'app/models/event.rb'
     - 'app/models/page.rb'
 
 Rails/HelperInstanceVariable:
@@ -114,6 +141,9 @@ Rails/SkipsModelValidations:
   Exclude:
     - 'app/controllers/application_controller.rb'
     - 'app/models/page.rb'
+    - 'app/services/event_change_registration_policy_service.rb'
+    - 'app/services/event_freeze_bucket_assignments_service.rb'
+    - 'app/services/execute_ranked_choice_signup_round_service.rb'
     - 'db/migrate/20251229184620_allow_null_redirect_uri_on_oauth_appliations.rb'
 
 # Offense count: 7
@@ -123,9 +153,52 @@ Rails/SkipsModelValidations:
 Style/FrozenStringLiteralComment:
   Exclude:
     - 'app/models/oauth_application.rb'
+    - 'app/services/event_freeze_bucket_assignments_service.rb'
     - 'config/initializers/cors.rb'
     - 'config/initializers/doorkeeper.rb'
     - 'config/initializers/doorkeeper_openid_connect.rb'
     - 'lib/intercode/virtual_host_constraint.rb'
+    - 'test/factories/event_proposals.rb'
     - 'test/factories/oauth_applications.rb'
+    - 'test/liquid_drops/convention_drop_test.rb'
+    - 'test/models/event_proposal_test.rb'
+    - 'test/models/event_test.rb'
+    - 'test/models/registration_policy/unlimited_test.rb'
+    - 'test/models/registration_policy_bucket_test.rb'
+    - 'test/models/registration_policy_test.rb'
     - 'test/policies/oauth_application_policy_test.rb'
+    - 'test/services/create_signup_request_service_test.rb'
+    - 'test/services/create_team_member_service_test.rb'
+    - 'test/services/event_change_registration_policy_service_test.rb'
+    - 'test/services/event_freeze_bucket_assignments_service_test.rb'
+    - 'test/services/event_signup_service_test.rb'
+    - 'test/services/event_vacancy_fill_service_test.rb'
+    - 'test/services/event_withdraw_service_test.rb'
+    - 'test/services/execute_ranked_choice_signup_round_service_test.rb'
+    - 'test/services/execute_ranked_choice_signup_service_test.rb'
+
+Layout/LineLength:
+  Exclude:
+    - 'test/models/registration_policy_bucket_test.rb'
+
+Lint/MissingSuper:
+  Exclude:
+    - 'app/services/accept_event_proposal_service.rb'
+    - 'app/services/event_change_registration_policy_service.rb'
+    - 'app/services/event_freeze_bucket_assignments_service.rb'
+    - 'app/services/execute_ranked_choice_signup_round_service.rb'
+
+Performance/StringInclude:
+  Exclude:
+    - 'test/models/registration_policy_test.rb'
+
+Rails/SquishedSQLHeredocs:
+  Exclude:
+    - 'app/services/execute_ranked_choice_signup_round_service.rb'
+
+Rails/TimeZone:
+  Exclude:
+    - 'app/models/convention.rb'
+    - 'test/services/event_vacancy_fill_service_test.rb'
+    - 'test/services/execute_ranked_choice_signup_round_service_test.rb'
+

app/graphql/mutations/freeze_bucket_assignments.rb

@@ -13,14 +13,14 @@ class Mutations::FreezeBucketAssignments < Mutations::BaseMutation
   load_and_authorize_convention_associated_model :events, :id, :update
 
   def resolve(**)
-    old_registration_policy = event.registration_policy.dup
+    old_registration_policy_json = event.registration_policy.as_json
 
     EventFreezeBucketAssignmentsService.new(event:, whodunit: current_user).call!
     event.reload
 
     log_form_response_changes(
       event,
-      { "registration_policy" => [old_registration_policy.as_json, event.registration_policy.as_json] }
+      { "registration_policy" => [old_registration_policy_json, event.registration_policy.as_json] }
     )
 
     { event: }

app/graphql/mutations/update_event.rb

@@ -28,15 +28,10 @@ def resolve(**args)
   private
 
   def apply_registration_policy(event, registration_policy_attributes, bucket_key_mappings)
-    new_registration_policy = RegistrationPolicy.new(registration_policy_attributes)
-    return {} if event.registration_policy == new_registration_policy
-
-    old_registration_policy = event.registration_policy
-    EventChangeRegistrationPolicyService.new(event, new_registration_policy, current_user, bucket_key_mappings).call!
-
-    event.reload
-
-    { "registration_policy" => [old_registration_policy.as_json, new_registration_policy.as_json] }
+    event.apply_registration_policy_change(registration_policy_attributes) do |new_registration_policy|
+      EventChangeRegistrationPolicyService.new(event, new_registration_policy, current_user, bucket_key_mappings).call!
+      event.reload
+    end
   end
 
   def apply_form_response_attrs(event, form_response_attrs)

app/graphql/mutations/update_event_proposal.rb

@@ -1,38 +1,68 @@
 # frozen_string_literal: true
 class Mutations::UpdateEventProposal < Mutations::BaseMutation
-  field :event_proposal, Types::EventProposalType, null: false
+  description "Update an event proposal"
 
-  argument :event_proposal, Types::EventProposalInputType, required: true, camelize: false
-  argument :id, ID, required: false
+  field :event_proposal, Types::EventProposalType, null: false, description: "The updated event proposal"
+
+  argument :event_proposal,
+           Types::EventProposalInputType,
+           required: true,
+           camelize: false,
+           description: "The event proposal attributes to update"
+  argument :id, ID, required: false, description: "The ID of the event proposal to update"
 
   load_and_authorize_convention_associated_model :event_proposals, :id, :update
 
-  # rubocop:disable Metrics/MethodLength
   def resolve(**args)
     event_proposal_attrs = args[:event_proposal].to_h.stringify_keys
+    form_response_attrs = JSON.parse(event_proposal_attrs.delete("form_response_attrs_json"))
+    registration_policy_attributes = form_response_attrs.delete("registration_policy")
+
+    changes = apply_registration_policy(event_proposal, registration_policy_attributes)
+    changes.update(apply_form_response_attrs(event_proposal, form_response_attrs))
+    event_proposal.assign_attributes(event_proposal_attrs)
+    event_proposal.save!
+
+    log_form_response_changes(event_proposal, changes) if event_proposal.status != "draft"
+
+    { event_proposal: }
+  end
+
+  private
+
+  def apply_registration_policy(event_proposal, registration_policy_attributes)
+    event_proposal.apply_registration_policy_change(registration_policy_attributes) do |new_registration_policy|
+      ActiveRecord::Base.transaction do
+        if event_proposal.registration_policy
+          event_proposal.registration_policy.update_from!(new_registration_policy)
+        else
+          event_proposal.registration_policy = new_registration_policy
+          event_proposal.save!
+        end
+      end
+    end
+  end
+
+  def apply_form_response_attrs(event_proposal, form_response_attrs)
     event_proposal.assign_form_response_attributes(
       event_proposal.filter_form_response_attributes_for_assignment(
-        JSON.parse(event_proposal_attrs.delete("form_response_attrs_json")),
+        form_response_attrs,
         event_proposal.event_category.event_proposal_form.form_items,
         context[:pundit_user]
       )
     )
-    event_proposal.assign_attributes(event_proposal_attrs)
-    event_proposal.save!
+    event_proposal.form_response_attribute_changes
+  end
 
-    if event_proposal.status != "draft"
-      event_proposal.form_response_attribute_changes.each do |(key, (previous_value, new_value))|
-        FormResponseChange.create!(
-          response: event_proposal,
-          user_con_profile:,
-          field_identifier: key,
-          previous_value:,
-          new_value:
-        )
-      end
+  def log_form_response_changes(event_proposal, changes)
+    changes.each do |(key, (previous_value, new_value))|
+      FormResponseChange.create!(
+        response: event_proposal,
+        user_con_profile:,
+        field_identifier: key,
+        previous_value:,
+        new_value:
+      )
     end
-
-    { event_proposal: }
   end
-  # rubocop:enable Metrics/MethodLength
 end

app/models/concerns/has_registration_policy.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+module HasRegistrationPolicy
+  extend ActiveSupport::Concern
+
+  # Builds a detached proposed RegistrationPolicy from `hash`, and -- if it actually differs
+  # from the current one -- captures an eager "before" JSON snapshot (the caller's block may
+  # update the current policy's rows in place rather than replacing them, so capturing
+  # afterward would show the already-updated state), yields the proposal for the caller to
+  # apply however is appropriate, and returns a {"registration_policy" => [old, new]} change
+  # hash for FormResponseChange logging. Returns {} if there's nothing to apply.
+  def apply_registration_policy_change(hash)
+    return {} unless hash
+
+    new_registration_policy = RegistrationPolicy.build_from_hash(hash)
+    return {} if registration_policy&.equivalent_to?(new_registration_policy)
+
+    old_registration_policy_json = registration_policy&.as_json
+    yield new_registration_policy
+    { "registration_policy" => [old_registration_policy_json, registration_policy.as_json] }
+  end
+end

app/models/convention.rb

@@ -199,7 +199,11 @@ def timezone
   end
 
   def bucket_metadata_from_events
-    events.pluck(:registration_policy).flat_map { |p| p.buckets.flat_map(&:metadata) }.uniq
+    RegistrationPolicyBucket
+      .where(registration_policy_id: events.select(:registration_policy_id))
+      .pluck(:key, :name, :description)
+      .map { |key, name, description| { key:, name:, description: } }
+      .uniq
   end
 
   def to_liquid

app/models/event.rb

@@ -56,6 +56,7 @@ class Event < ApplicationRecord
   include AgeRestrictions
   include EventEmail
   include FormResponse
+  include HasRegistrationPolicy
   include MarkdownIndexing
   include OrderByTitle
   include PgSearch::Model
@@ -116,6 +117,7 @@ class Event < ApplicationRecord
 
   belongs_to :convention
   belongs_to :event_category
+  belongs_to :registration_policy, inverse_of: :events, dependent: :destroy
 
   has_many :maximum_event_provided_tickets_overrides, dependent: :destroy
   has_many :provided_tickets, class_name: "Ticket", inverse_of: "provided_by_event", foreign_key: "provided_by_event_id"
@@ -199,8 +201,6 @@ class Event < ApplicationRecord
 
   scope :active, -> { where(status: "active") }
 
-  serialize :registration_policy, coder: ActiveModelCoder.new("RegistrationPolicy")
-
   attr_accessor :bypass_single_event_run_check, :allow_registration_policy_change
 
   def to_param
@@ -266,12 +266,12 @@ def single_run_events_must_have_no_more_than_one_run
 
   def registration_policy_cannot_change
     return if new_record?
-    return unless registration_policy_changed?
+    return unless registration_policy_id_changed?
 
-    before, after = changes["registration_policy"]
+    before, after = changes["registration_policy_id"]
     return if before == after # ActiveRecord is being overzealous about change detection
 
-    errors.add :registration_policy,
+    errors.add :registration_policy_id,
                "cannot be changed via ActiveRecord on an existing event.  \
 Use EventChangeRegistrationPolicyService instead."
   end

app/models/event_proposal.rb

@@ -11,7 +11,6 @@
 #  description            :text
 #  email                  :text
 #  length_seconds         :integer
-#  registration_policy    :jsonb
 #  reminded_at            :datetime
 #  short_blurb            :text
 #  status                 :string
@@ -25,27 +24,31 @@
 #  event_category_id      :bigint           not null
 #  event_id               :bigint
 #  owner_id               :bigint
+#  registration_policy_id :bigint
 #
 # Indexes
 #
-#  index_event_proposals_on_convention_id      (convention_id)
-#  index_event_proposals_on_event_category_id  (event_category_id)
-#  index_event_proposals_on_event_id           (event_id)
-#  index_event_proposals_on_owner_id           (owner_id)
+#  index_event_proposals_on_convention_id           (convention_id)
+#  index_event_proposals_on_event_category_id       (event_category_id)
+#  index_event_proposals_on_event_id                (event_id)
+#  index_event_proposals_on_owner_id                (owner_id)
+#  index_event_proposals_on_registration_policy_id  (registration_policy_id)
 #
 # Foreign Keys
 #
 #  fk_rails_...  (convention_id => conventions.id)
 #  fk_rails_...  (event_category_id => event_categories.id)
 #  fk_rails_...  (event_id => events.id)
 #  fk_rails_...  (owner_id => user_con_profiles.id)
+#  fk_rails_...  (registration_policy_id => registration_policies.id)
 #
 # rubocop:enable Layout/LineLength, Lint/RedundantCopDisableDirective
 
 class EventProposal < ApplicationRecord
   include AgeRestrictions
   include EventEmail
   include FormResponse
+  include HasRegistrationPolicy
   include MarkdownIndexing
   include OrderByTitle
   include PgSearch::Model
@@ -68,6 +71,7 @@ class EventProposal < ApplicationRecord
   belongs_to :owner, class_name: "UserConProfile", optional: true
   belongs_to :event, optional: true
   belongs_to :event_category
+  belongs_to :registration_policy, inverse_of: :event_proposals, optional: true, dependent: :destroy
 
   has_many_attached :images
 
@@ -77,7 +81,6 @@ class EventProposal < ApplicationRecord
   scope :reminded, -> { where.not(reminded_at: nil) }
   scope :not_reminded, -> { where(reminded_at: nil) }
 
-  serialize :registration_policy, coder: ActiveModelCoder.new("RegistrationPolicy")
   serialize :timeblock_preferences,
             coder: JSONArrayCoderWrapper.new(ActiveModelCoder.new("EventProposal::TimeblockPreference"))