Add version_id column to Deletions

So we can use a straightforward foreign key relationship between the version & deletion

app/models/deletion.rb

@@ -47,6 +47,7 @@ def record_metadata
     self.rubygem = rubygem_name
     self.number = version.number
     self.platform = version.platform
+    self.version_id = version.id
   end
 
   def expire_cache

app/models/user.rb

@@ -27,6 +27,7 @@ class User < ApplicationRecord
   has_many :subscribed_gems, -> { order("name ASC") }, through: :subscriptions, source: :rubygem
 
   has_many :pushed_versions, -> { by_created_at }, dependent: :nullify, inverse_of: :pusher, class_name: "Version", foreign_key: :pusher_id
+  has_many :yanked_versions, through: :deletions, source: :version
 
   has_many :deletions, dependent: :nullify
   has_many :web_hooks, dependent: :destroy

app/tasks/maintenance/backfill_deletion_versions_task.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+class Maintenance::BackfillDeletionVersionsTask < MaintenanceTasks::Task
+  def collection
+    Deletion.all
+  end
+
+  def process(deletion)
+    return if deletion.version_id?
+
+    deletion.update!(version_id: deletion.version.id)
+  end
+end

db/migrate/20231129233528_add_version_id_to_deletions.rb

@@ -0,0 +1,7 @@
+class AddVersionIdToDeletions < ActiveRecord::Migration[7.0]
+  disable_ddl_transaction!
+
+  def change
+    add_reference :deletions, :version, index: {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[7.0].define(version: 2023_11_20_033411) do
+ActiveRecord::Schema[7.0].define(version: 2023_11_29_233528) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "hstore"
   enable_extension "pgcrypto"
@@ -83,7 +83,9 @@
     t.string "platform"
     t.datetime "created_at", precision: nil, null: false
     t.datetime "updated_at", precision: nil, null: false
+    t.bigint "version_id"
     t.index ["user_id"], name: "index_deletions_on_user_id"
+    t.index ["version_id"], name: "index_deletions_on_version_id"
   end
 
   create_table "dependencies", id: :serial, force: :cascade do |t|

test/models/deletion_test.rb

@@ -121,6 +121,7 @@ class DeletionTest < ActiveSupport::TestCase
     deletion.valid?
 
     assert_equal deletion.rubygem, @version.rubygem.name
+    assert_equal @version.id, deletion.version_id
   end
 
   context "with restored gem" do

test/tasks/maintenance/backfill_deletion_versions_task_test.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+class Maintenance::BackfillDeletionVersionsTaskTest < ActiveSupport::TestCase
+  test "#collection" do
+    assert_equal Deletion.all, Maintenance::BackfillDeletionVersionsTask.collection
+  end
+
+  test "#process" do
+    version = create(:version)
+    deletion = create(:deletion, version:)
+
+    deletion.update_column(:version_id, nil)
+
+    assert_nil deletion.version_id
+
+    Maintenance::BackfillDeletionVersionsTask.process(deletion)
+
+    assert_equal version.id, deletion.version_id
+    assert_equal version, deletion.version
+
+    assert_no_changes -> { deletion.reload.as_json } do
+      Maintenance::BackfillDeletionVersionsTask.process(deletion)
+    end
+  end
+end