Federated reports (#6570)

* Fix #2176: Federated reports

* UI for federated reports

* Add spec for ActivityPub Flag handler

* Add spec for ReportService

spec/services/report_service_spec.rb

@@ -0,0 +1,25 @@
+require 'rails_helper'
+
+RSpec.describe ReportService do
+  subject { described_class.new }
+
+  let(:source_account) { Fabricate(:account) }
+
+  context 'for a remote account' do
+    let(:remote_account) { Fabricate(:account, domain: 'example.com', protocol: :activitypub, inbox_url: 'http://example.com/inbox') }
+
+    before do
+      stub_request(:post, 'http://example.com/inbox').to_return(status: 200)
+    end
+
+    it 'sends ActivityPub payload when forward is true' do
+      subject.call(source_account, remote_account, forward: true)
+      expect(a_request(:post, 'http://example.com/inbox')).to have_been_made
+    end
+
+    it 'does not send anything when forward is false' do
+      subject.call(source_account, remote_account, forward: false)
+      expect(a_request(:post, 'http://example.com/inbox')).to_not have_been_made
+    end
+  end
+end