Fix NoMethodError in StatusUpdateDistributionWorker (#17499)

* Add tests

* Fix NoMethodError in StatusUpdateDistributionWorker

* Fix tests

app/workers/activitypub/status_update_distribution_worker.rb

@@ -6,6 +6,7 @@ class ActivityPub::StatusUpdateDistributionWorker < ActivityPub::DistributionWor
   def perform(status_id, options = {})
     @options = options.with_indifferent_access
     @status  = Status.find(status_id)
+    @account = @status.account
 
     distribute!
   rescue ActiveRecord::RecordNotFound

spec/workers/activitypub/status_update_distribution_worker_spec.rb

+require 'rails_helper'
+
+describe ActivityPub::StatusUpdateDistributionWorker do
+  subject { described_class.new }
+
+  let(:status)   { Fabricate(:status, text: 'foo') }
+  let(:follower) { Fabricate(:account, protocol: :activitypub, inbox_url: 'http://example.com') }
+
+  describe '#perform' do
+    before do
+      follower.follow!(status.account)
+
+      status.snapshot!
+      status.text = 'bar'
+      status.edited_at = Time.now.utc
+      status.snapshot!
+      status.save!
+    end
+
+    context 'with public status' do
+      before do
+        status.update(visibility: :public)
+      end
+
+      it 'delivers to followers' do
+        expect(ActivityPub::DeliveryWorker).to receive(:push_bulk) do |items, &block|
+          expect(items.map(&block)).to match([[kind_of(String), status.account.id, 'http://example.com', anything]])
+        end
+
+        subject.perform(status.id)
+      end
+    end
+
+    context 'with private status' do
+      before do
+        status.update(visibility: :private)
+      end
+
+      it 'delivers to followers' do
+        expect(ActivityPub::DeliveryWorker).to receive(:push_bulk) do |items, &block|
+          expect(items.map(&block)).to match([[kind_of(String), status.account.id, 'http://example.com', anything]])
+        end
+
+        subject.perform(status.id)
+      end
+    end
+  end
+end