Fix compatibility with Friendica regarding pinned posts (#18254)

* Fix multiple database queries when fetching pinned posts for remote account

* Fix compatibility with Friendica regarding pinned posts

Fixes #18066

* Add tests

1 files changed, 123 insertions, 0 deletions

diff --git a/spec/services/activitypub/fetch_featured_collection_service_spec.rb b/spec/services/activitypub/fetch_featured_collection_service_spec.rb
new file mode 100644
index 000000000..f552b9dc0
--- /dev/null
+++ b/spec/services/activitypub/fetch_featured_collection_service_spec.rb
@@ -0,0 +1,123 @@
+require 'rails_helper'
+
+RSpec.describe ActivityPub::FetchFeaturedCollectionService, type: :service do
+  let(:actor) { Fabricate(:account, domain: 'example.com', uri: 'https://example.com/account', featured_collection_url: 'https://example.com/account/pinned') }
+
+  let!(:known_status) { Fabricate(:status, account: actor, uri: 'https://example.com/account/pinned/1') }
+
+  let(:status_json_1) do
+    {
+      '@context': 'https://www.w3.org/ns/activitystreams',
+      type: 'Note',
+      id: 'https://example.com/account/pinned/1',
+      content: 'foo',
+      attributedTo: actor.uri,
+      to: 'https://www.w3.org/ns/activitystreams#Public',
+    }
+  end
+
+  let(:status_json_2) do
+    {
+      '@context': 'https://www.w3.org/ns/activitystreams',
+      type: 'Note',
+      id: 'https://example.com/account/pinned/2',
+      content: 'foo',
+      attributedTo: actor.uri,
+      to: 'https://www.w3.org/ns/activitystreams#Public',
+    }
+  end
+
+  let(:status_json_4) do
+    {
+      '@context': 'https://www.w3.org/ns/activitystreams',
+      type: 'Note',
+      id: 'https://example.com/account/pinned/4',
+      content: 'foo',
+      attributedTo: actor.uri,
+      to: 'https://www.w3.org/ns/activitystreams#Public',
+    }
+  end
+
+  let(:items) do
+    [
+      'https://example.com/account/pinned/1', # known
+      status_json_2, # unknown inlined
+      'https://example.com/account/pinned/3', # unknown unreachable
+      'https://example.com/account/pinned/4', # unknown reachable
+    ]
+  end
+
+  let(:payload) do
+    {
+      '@context': 'https://www.w3.org/ns/activitystreams',
+      type: 'Collection',
+      id: actor.featured_collection_url,
+      items: items,
+    }.with_indifferent_access
+  end
+
+  subject { described_class.new }
+
+  shared_examples 'sets pinned posts' do
+    before do
+      stub_request(:get, 'https://example.com/account/pinned/1').to_return(status: 200, body: Oj.dump(status_json_1))
+      stub_request(:get, 'https://example.com/account/pinned/2').to_return(status: 200, body: Oj.dump(status_json_2))
+      stub_request(:get, 'https://example.com/account/pinned/3').to_return(status: 404)
+      stub_request(:get, 'https://example.com/account/pinned/4').to_return(status: 200, body: Oj.dump(status_json_4))
+
+      subject.call(actor)
+    end
+
+    it 'sets expected posts as pinned posts' do
+      expect(actor.pinned_statuses.pluck(:uri)).to match_array ['https://example.com/account/pinned/1', 'https://example.com/account/pinned/2', 'https://example.com/account/pinned/4']
+    end
+  end
+
+  describe '#call' do
+    context 'when the endpoint is a Collection' do
+      before do
+        stub_request(:get, actor.featured_collection_url).to_return(status: 200, body: Oj.dump(payload))
+      end
+
+      it_behaves_like 'sets pinned posts'
+    end
+
+    context 'when the endpoint is an OrderedCollection' do
+      let(:payload) do
+        {
+          '@context': 'https://www.w3.org/ns/activitystreams',
+          type: 'OrderedCollection',
+          id: actor.featured_collection_url,
+          orderedItems: items,
+        }.with_indifferent_access
+      end
+
+      before do
+        stub_request(:get, actor.featured_collection_url).to_return(status: 200, body: Oj.dump(payload))
+      end
+
+      it_behaves_like 'sets pinned posts'
+    end
+
+    context 'when the endpoint is a paginated Collection' do
+      let(:payload) do
+        {
+          '@context': 'https://www.w3.org/ns/activitystreams',
+          type: 'Collection',
+          id: actor.featured_collection_url,
+          first: {
+            type: 'CollectionPage',
+            partOf: actor.featured_collection_url,
+            items: items,
+          }
+        }.with_indifferent_access
+      end
+
+      before do
+        stub_request(:get, actor.featured_collection_url).to_return(status: 200, body: Oj.dump(payload))
+      end
+
+      it_behaves_like 'sets pinned posts'
+    end
+  end
+end