Add support for Link objects in attachment (#36104)

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

app/lib/activitypub/activity/create.rb

@@ -50,6 +50,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
     @tags                 = []
     @mentions             = []
     @tagged_objects       = []
+    @links                = []
     @unresolved_mentions  = []
     @unresolved_collections = []
     @silenced_account_ids = []
@@ -82,7 +83,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
 
   def distribute
     # Spread out crawling randomly to avoid DDoSing the link
-    LinkCrawlWorker.perform_in(rand(DISTRIBUTE_DELAY), @status.id)
+    LinkCrawlWorker.perform_in(rand(DISTRIBUTE_DELAY), @status.id, @links.first)
 
     # Distribute into home and list feeds and notify mentioned accounts
     ::DistributionWorker.perform_async(@status.id, { 'silenced_account_ids' => @silenced_account_ids }) if @options[:override_timestamps] || @status.within_realtime_window?
@@ -297,6 +298,12 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
     media_attachments = []
 
     as_array(@object['attachment']).each do |attachment|
+      if attachment['href'].present?
+        preview_card_parser = ActivityPub::Parser::PreviewCardParser.new(attachment)
+        @links << preview_card_parser.url if preview_card_parser.url.present?
+        next
+      end
+
       media_attachment_parser = ActivityPub::Parser::MediaAttachmentParser.new(attachment)
 
       next if media_attachment_parser.remote_url.blank? || media_attachments.size >= Status::MEDIA_ATTACHMENTS_LIMIT

app/lib/activitypub/parser/preview_card_parser.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+class ActivityPub::Parser::PreviewCardParser
+  include JsonLdHelper
+
+  def initialize(json)
+    @json = json
+  end
+
+  # @param [PreviewCard] previous_record
+  def significantly_changes?(previous_record)
+    url != previous_record.url
+  end
+
+  def url
+    url = Addressable::URI.parse(@json['href'])&.normalize&.to_s
+    url unless unsupported_uri_scheme?(url)
+  rescue Addressable::URI::InvalidURIError
+    nil
+  end
+end

app/serializers/activitypub/note_serializer.rb

@@ -135,7 +135,7 @@ class ActivityPub::NoteSerializer < ActivityPub::Serializer
   end
 
   def virtual_attachments
-    object.ordered_media_attachments
+    object.ordered_media_attachments + [object.preview_card].compact
   end
 
   def virtual_tags
@@ -248,6 +248,18 @@ class ActivityPub::NoteSerializer < ActivityPub::Serializer
     }
   end
 
+  class PreviewCardSerializer < ActivityPub::Serializer
+    attributes :type, :href
+
+    def type
+      'Link'
+    end
+
+    def href
+      object.original_url.presence || object.url
+    end
+  end
+
   class MediaAttachmentSerializer < ActivityPub::Serializer
     context_extensions :blurhash, :focal_point
 

app/services/activitypub/process_status_update_service.rb

@@ -22,6 +22,8 @@ class ActivityPub::ProcessStatusUpdateService < BaseService
     @quote_changed             = false
     @request_id                = request_id
     @quote                     = nil
+    @next_media_attachments    = []
+    @next_links                = []
 
     return @status if !expected_type? || already_updated_more_recently?
 
@@ -87,9 +89,14 @@ class ActivityPub::ProcessStatusUpdateService < BaseService
   def update_media_attachments!
     previous_media_attachments     = @status.media_attachments.to_a
     previous_media_attachments_ids = @status.ordered_media_attachment_ids || previous_media_attachments.map(&:id)
-    @next_media_attachments        = []
 
     as_array(@json['attachment']).each do |attachment|
+      if attachment['href'].present?
+        preview_card_parser = ActivityPub::Parser::PreviewCardParser.new(attachment)
+        @next_links << preview_card_parser.url if preview_card_parser.url.present?
+        next
+      end
+
       media_attachment_parser = ActivityPub::Parser::MediaAttachmentParser.new(attachment)
 
       next if media_attachment_parser.remote_url.blank? || @next_media_attachments.size > Status::MEDIA_ATTACHMENTS_LIMIT
@@ -385,7 +392,8 @@ class ActivityPub::ProcessStatusUpdateService < BaseService
 
   def update_counts!
     likes = @status_parser.favourites_count
-    shares =  @status_parser.reblogs_count
+    shares = @status_parser.reblogs_count
+
     return if likes.nil? && shares.nil?
 
     @status.status_stat.tap do |status_stat|
@@ -438,7 +446,7 @@ class ActivityPub::ProcessStatusUpdateService < BaseService
 
   def reset_preview_card!
     @status.reset_preview_card!
-    LinkCrawlWorker.perform_in(rand(CRAWL_DELAY), @status.id)
+    LinkCrawlWorker.perform_in(rand(CRAWL_DELAY), @status.id, @next_links.first)
   end
 
   def broadcast_updates!

app/services/fetch_link_card_service.rb

@@ -15,9 +15,9 @@ class FetchLinkCardService < BaseService
     )
   }iox
 
-  def call(status)
+  def call(status, original_url = nil)
     @status       = status
-    @original_url = parse_urls
+    @original_url = original_url || parse_urls
 
     return if @original_url.nil? || @status.with_preview_card? || @status.with_media? || @status.quote.present?
 

app/workers/link_crawl_worker.rb

@@ -5,8 +5,8 @@ class LinkCrawlWorker
 
   sidekiq_options queue: 'pull', retry: 0
 
-  def perform(status_id)
-    FetchLinkCardService.new.call(Status.find(status_id))
+  def perform(status_id, url = nil)
+    FetchLinkCardService.new.call(Status.find(status_id), url)
   rescue ActiveRecord::RecordNotFound, ActiveRecord::RecordNotUnique
     true
   end

spec/lib/activitypub/activity/create_spec.rb

@@ -277,24 +277,16 @@ RSpec.describe ActivityPub::Activity::Create do
         end
       end
 
-      context 'with a standalone' do
+      context 'with a standalone post' do
         let(:object_json) { build_object }
 
-        it 'creates status' do
+        it 'creates a status with expected text and direct privacy' do
           expect { subject.perform }.to change(sender.statuses, :count).by(1)
 
           status = sender.statuses.first
 
           expect(status).to_not be_nil
           expect(status.text).to eq 'Lorem ipsum'
-        end
-
-        it 'missing to/cc defaults to direct privacy' do
-          expect { subject.perform }.to change(sender.statuses, :count).by(1)
-
-          status = sender.statuses.first
-
-          expect(status).to_not be_nil
           expect(status.visibility).to eq 'direct'
         end
       end
@@ -333,6 +325,55 @@ RSpec.describe ActivityPub::Activity::Create do
         end
       end
 
+      context 'with a public status mentioning multiple links' do
+        let(:object_json) do
+          build_object(
+            to: 'as:Public',
+            content: 'This is a test <a href="https://joinmastodon.org">https://joinmastodon.org</a> <a href="https://activitypub.rocks/">https://activitypub.rocks/</a>'
+          )
+        end
+
+        it 'creates a status and schedules link fetching job for first link' do
+          expect { subject.perform }
+            .to change(sender.statuses, :count).by(1)
+
+          status = sender.statuses.first
+
+          expect(status).to_not be_nil
+
+          expect(LinkCrawlWorker).to have_enqueued_sidekiq_job(status.id, nil)
+
+          expect(status.visibility).to eq 'public'
+        end
+      end
+
+      context 'with a public status specifying a link attachment (FEP-8967)' do
+        let(:object_json) do
+          build_object(
+            to: 'as:Public',
+            content: 'This is a test <a href="https://joinmastodon.org">https://joinmastodon.org</a> <a href="https://activitypub.rocks/">https://activitypub.rocks/</a>',
+            attachment: [
+              {
+                href: 'https://activitypub.rocks/',
+              },
+            ]
+          )
+        end
+
+        it 'creates a status and schedules link fetching job for specified link' do
+          expect { subject.perform }
+            .to change(sender.statuses, :count).by(1)
+
+          status = sender.statuses.first
+
+          expect(status).to_not be_nil
+
+          expect(LinkCrawlWorker).to have_enqueued_sidekiq_job(status.id, 'https://activitypub.rocks/')
+
+          expect(status.visibility).to eq 'public'
+        end
+      end
+
       context 'when public with Public' do
         let(:object_json) do
           build_object(

spec/serializers/activitypub/note_serializer_spec.rb

@@ -107,4 +107,23 @@ RSpec.describe ActivityPub::NoteSerializer do
       })
     end
   end
+
+  context 'with a preview card' do
+    let(:preview_card) { Fabricate(:preview_card) }
+
+    before do
+      PreviewCardsStatus.create(status: parent, preview_card: preview_card)
+    end
+
+    it 'has the expected shape (using FEP-8967)' do
+      expect(subject).to include({
+        'type' => 'Note',
+        'attachment' => contain_exactly(
+          a_hash_including(
+            'href' => preview_card.url
+          )
+        ),
+      })
+    end
+  end
 end