Add validation spec for Form::Redirect model (#38011)

spec/models/form/redirect_spec.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Form::Redirect do
+  describe 'Validations' do
+    it { is_expected.to validate_presence_of(:acct) }
+
+    describe 'target account validation' do
+      subject { described_class.new(account:) }
+
+      context 'when target_account is missing' do
+        let(:account) { Fabricate.build :account }
+
+        it { is_expected.to_not allow_value(nil).for(:target_account).against(:acct).with_message(I18n.t('migrations.errors.not_found')) }
+      end
+
+      context 'when account already moved' do
+        let(:account) { Fabricate.build :account, moved_to_account_id: target_account.id }
+        let(:target_account) { Fabricate :account }
+
+        it { is_expected.to_not allow_value(target_account).for(:target_account).against(:acct).with_message(I18n.t('migrations.errors.already_moved')) }
+      end
+
+      context 'when moving to self' do
+        let(:account) { Fabricate :account }
+
+        it { is_expected.to_not allow_value(account).for(:target_account).against(:acct).with_message(I18n.t('migrations.errors.move_to_self')) }
+      end
+    end
+  end
+end