Start of handling FeatureRequest activities (#38193)

app/lib/activitypub/activity.rb

@@ -59,6 +59,8 @@ class ActivityPub::Activity
         ActivityPub::Activity::Move
       when 'QuoteRequest'
         ActivityPub::Activity::QuoteRequest
+      when 'FeatureRequest'
+        ActivityPub::Activity::FeatureRequest
       end
     end
   end

app/lib/activitypub/activity/feature_request.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+class ActivityPub::Activity::FeatureRequest < ActivityPub::Activity
+  include Payloadable
+
+  def perform
+    return unless Mastodon::Feature.collections_federation_enabled?
+    return if non_matching_uri_hosts?(@account.uri, @json['id'])
+
+    @collection = @account.collections.find_by(uri: value_or_id(@json['instrument']))
+    @featured_account = ActivityPub::TagManager.instance.uris_to_local_accounts([value_or_id(@json['object'])]).first
+
+    return if @collection.nil? || @featured_account.nil?
+
+    if AccountPolicy.new(@account, @featured_account).feature?
+      accept_request!
+    else
+      reject_request!
+    end
+  end
+
+  private
+
+  def accept_request!
+    collection_item = @collection.collection_items.create!(
+      account: @featured_account,
+      state: :accepted
+    )
+
+    queue_delivery!(collection_item, ActivityPub::AcceptFeatureRequestSerializer)
+  end
+
+  def reject_request!
+    collection_item = @collection.collection_items.build(
+      account: @featured_account,
+      state: :rejected
+    )
+
+    queue_delivery!(collection_item, ActivityPub::RejectFeatureRequestSerializer)
+  end
+
+  def queue_delivery!(collection_item, serializer)
+    json = Oj.dump(serialize_payload(collection_item, serializer))
+    ActivityPub::DeliveryWorker.perform_async(json, @featured_account.id, @account.inbox_url)
+  end
+end

app/models/collection_item.rb

@@ -32,7 +32,7 @@ class CollectionItem < ApplicationRecord
   validates :approval_uri, presence: true, unless: -> { local? || account&.local? }
   validates :account, presence: true, if: :accepted?
   validates :object_uri, presence: true, if: -> { account.nil? }
-  validates :uri, presence: true, if: :remote?
+  validates :uri, presence: true, if: :remote_item_with_remote_account?
 
   before_validation :set_position, on: :create
   before_validation :set_activity_uri, only: :create, if: :local_item_with_remote_account?
@@ -50,6 +50,10 @@ class CollectionItem < ApplicationRecord
     local? && account&.remote?
   end
 
+  def remote_item_with_remote_account?
+    remote? && account&.remote?
+  end
+
   def object_type
     :featured_item
   end

spec/lib/activitypub/activity/feature_request_spec.rb

@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe ActivityPub::Activity::FeatureRequest do
+  let(:sender)    { Fabricate(:remote_account) }
+  let(:recipient) { Fabricate(:account, discoverable:) }
+  let(:collection) { Fabricate(:remote_collection, account: sender) }
+
+  let(:json) do
+    {
+      '@context' => [
+        'https://www.w3.org/ns/activitystreams',
+      ],
+      'id' => 'https://example.com/feature_requests/1',
+      'type' => 'FeatureRequest',
+      'actor' => sender.uri,
+      'object' => ActivityPub::TagManager.instance.uri_for(recipient),
+      'instrument' => collection.uri,
+    }
+  end
+
+  describe '#perform', feature: :collections_federation do
+    subject { described_class.new(json, sender) }
+
+    context 'when recipient is discoverable' do
+      let(:discoverable) { true }
+
+      it 'schedules a job to send an `Accept` activity' do
+        expect { subject.perform }
+          .to enqueue_sidekiq_job(ActivityPub::DeliveryWorker)
+          .with(satisfying do |body|
+            response_json = JSON.parse(body)
+            response_json['type'] == 'Accept' &&
+              response_json['to'] == sender.uri
+          end, recipient.id, sender.inbox_url)
+      end
+    end
+
+    context 'when recipient is not discoverable' do
+      let(:discoverable) { false }
+
+      it 'schedules a job to send a `Reject` activity' do
+        expect { subject.perform }
+          .to enqueue_sidekiq_job(ActivityPub::DeliveryWorker)
+          .with(satisfying do |body|
+            response_json = JSON.parse(body)
+            response_json['type'] == 'Reject' &&
+              response_json['to'] == sender.uri
+          end, recipient.id, sender.inbox_url)
+      end
+    end
+  end
+end

spec/models/collection_item_spec.rb

@@ -17,8 +17,9 @@ RSpec.describe CollectionItem do
     end
 
     context 'when item is not local' do
-      subject { Fabricate.build(:collection_item, collection: remote_collection) }
+      subject { Fabricate.build(:collection_item, collection: remote_collection, account:) }
 
+      let(:account) { Fabricate.build(:remote_account) }
       let(:remote_collection) { Fabricate.build(:collection, local: false) }
 
       it { is_expected.to validate_presence_of(:uri) }
@@ -28,6 +29,12 @@ RSpec.describe CollectionItem do
 
         it { is_expected.to validate_presence_of(:approval_uri) }
       end
+
+      context 'when account is local' do
+        let(:account) { Fabricate.build(:account) }
+
+        it { is_expected.to_not validate_presence_of(:uri) }
+      end
     end
 
     context 'when account is not present' do