Add basic coverage for `MoveService` class (#29301)

spec/services/move_service_spec.rb

@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe MoveService do
+  subject { described_class.new.call(migration) }
+
+  context 'with a valid migration record' do
+    let(:migration) { Fabricate(:account_migration, account: source_account, target_account: target_account) }
+    let(:source_account) { Fabricate(:account) }
+    let(:target_account) { Fabricate(:account, also_known_as: [source_account_uri]) }
+
+    it 'migrates the account to a new account' do
+      expect { subject }
+        .to change_source_moved_value
+        .and process_local_updates
+        .and distribute_updates
+        .and distribute_move
+    end
+  end
+
+  def source_account_uri
+    ActivityPub::TagManager
+      .instance
+      .uri_for(source_account)
+  end
+
+  def change_source_moved_value
+    change(source_account.reload, :moved_to_account)
+      .from(nil)
+      .to(target_account)
+  end
+
+  def process_local_updates
+    enqueue_sidekiq_job(MoveWorker)
+      .with(source_account.id, target_account.id)
+  end
+
+  def distribute_updates
+    enqueue_sidekiq_job(ActivityPub::UpdateDistributionWorker)
+      .with(source_account.id)
+  end
+
+  def distribute_move
+    enqueue_sidekiq_job(ActivityPub::MoveDistributionWorker)
+      .with(migration.id)
+  end
+end