Add collections to Flag activities (#38817)

app/lib/activitypub/activity.rb

@@ -75,6 +75,10 @@ class ActivityPub::Activity
     ActivityPub::TagManager.instance.uri_to_resource(uri, Account)
   end
 
+  def collection_from_uri(uri)
+    ActivityPub::TagManager.instance.uri_to_resource(uri, Collection)
+  end
+
   def object_uri
     @object_uri ||= uri_from_bearcap(value_or_id(@object))
   end

app/lib/activitypub/activity/flag.rb

@@ -8,9 +8,11 @@ class ActivityPub::Activity::Flag < ActivityPub::Activity
 
     target_accounts            = object_uris.filter_map { |uri| account_from_uri(uri) }
     target_statuses_by_account = object_uris.filter_map { |uri| status_from_uri(uri) }.group_by(&:account_id)
+    target_collections_by_account = object_uris.filter_map { |uri| collection_from_uri(uri) }.group_by(&:account_id)
 
     target_accounts.each do |target_account|
       target_statuses     = target_statuses_by_account[target_account.id]
+      target_collections  = target_collections_by_account.fetch(target_account.id, [])
       replied_to_accounts = target_statuses.nil? ? [] : Account.local.where(id: target_statuses.filter_map(&:in_reply_to_account_id))
 
       next if target_account.suspended? || (!target_account.local? && replied_to_accounts.none?)
@@ -19,6 +21,7 @@ class ActivityPub::Activity::Flag < ActivityPub::Activity
         @account,
         target_account,
         status_ids: target_statuses.nil? ? [] : target_statuses.map(&:id),
+        collection_ids: target_collections.map(&:id),
         comment: report_comment,
         uri: report_uri
       )

app/serializers/activitypub/flag_serializer.rb

@@ -17,10 +17,24 @@ class ActivityPub::FlagSerializer < ActivityPub::Serializer
   end
 
   def virtual_object
-    [ActivityPub::TagManager.instance.uri_for(object.target_account)] + object.statuses.map { |s| ActivityPub::TagManager.instance.uri_for(s) }
+    target_account_uris + status_uris + collection_uris
   end
 
   def content
     object.comment
   end
+
+  private
+
+  def target_account_uris
+    [ActivityPub::TagManager.instance.uri_for(object.target_account)]
+  end
+
+  def status_uris
+    object.statuses.map { |s| ActivityPub::TagManager.instance.uri_for(s) }
+  end
+
+  def collection_uris
+    object.collections.map { |c| ActivityPub::TagManager.instance.uri_for(c) }
+  end
 end

spec/lib/activitypub/activity/flag_spec.rb

@@ -143,7 +143,34 @@ RSpec.describe ActivityPub::Activity::Flag do
       end
     end
 
-    context 'when an account is passed but no status' do
+    context 'when the activity includes and account and a collection' do
+      let(:collection) { Fabricate(:collection, account: flagged) }
+      let(:json) do
+        {
+          '@context' => 'https://www.w3.org/ns/activitystreams',
+          'id' => flag_id,
+          'type' => 'Flag',
+          'content' => 'Boo!!',
+          'actor' => ActivityPub::TagManager.instance.uri_for(sender),
+          'object' => [
+            ActivityPub::TagManager.instance.uri_for(flagged),
+            ActivityPub::TagManager.instance.uri_for(collection),
+          ],
+        }
+      end
+
+      it 'creates a report with an attached collection' do
+        subject.perform
+
+        report = Report.find_by(account: sender, target_account: flagged)
+
+        expect(report).to_not be_nil
+        expect(report.comment).to eq 'Boo!!'
+        expect(report.collections).to contain_exactly(collection)
+      end
+    end
+
+    context 'when an account is passed but no status or collection' do
       let(:mentioned) { Fabricate(:account) }
 
       let(:json) do

spec/serializers/activitypub/flag_serializer_spec.rb

@@ -22,4 +22,34 @@ RSpec.describe ActivityPub::FlagSerializer do
     expect(subject).to_not have_key('cc')
     expect(subject).to_not have_key('target')
   end
+
+  context 'with status' do
+    let(:target_account) { Fabricate(:account) }
+    let(:status) { Fabricate(:status, account: target_account) }
+    let(:report) { Fabricate(:report, target_account:, status_ids: [status.id]) }
+
+    it 'includes the status URI in `object`' do
+      expect(subject).to include({
+        'object' => [
+          tag_manager.uri_for(target_account),
+          tag_manager.uri_for(status),
+        ],
+      })
+    end
+  end
+
+  context 'with collection', feature: :collections do
+    let(:target_account) { Fabricate(:account) }
+    let(:collection) { Fabricate(:collection, account: target_account) }
+    let(:report) { Fabricate(:report, target_account:, collections: [collection]) }
+
+    it 'includes the collection URI in `object`' do
+      expect(subject).to include({
+        'object' => [
+          tag_manager.uri_for(target_account),
+          tag_manager.uri_for(collection),
+        ],
+      })
+    end
+  end
 end