1 files changed, 138 insertions, 0 deletions
diff --git a/spec/serializers/activity_pub/activity_serializer_spec.rb b/spec/serializers/activity_pub/activity_serializer_spec.rb
new file mode 100644
index 00000000000..93b52614490
--- /dev/null
+++ b/spec/serializers/activity_pub/activity_serializer_spec.rb
@@ -0,0 +1,138 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe ActivityPub::ActivitySerializer, feature_category: :integrations do
+  let(:implementer_class) do
+    Class.new(described_class)
+  end
+
+  let(:serializer) { implementer_class.new.represent(resource) }
+
+  let(:resource) { build_stubbed(:release) }
+
+  let(:transitive_entity_class) do
+    Class.new(Grape::Entity) do
+      expose :id do |*|
+        'https://example.com/unique/url'
+      end
+
+      expose :type do |*|
+        'Follow'
+      end
+
+      expose :actor do |*|
+        'https://example.com/actor/alice'
+      end
+
+      expose :object do |*|
+        'https://example.com/actor/bob'
+      end
+    end
+  end
+
+  let(:intransitive_entity_class) do
+    Class.new(Grape::Entity) do
+      expose :id do |*|
+        'https://example.com/unique/url'
+      end
+
+      expose :type do |*|
+        'Question'
+      end
+
+      expose :actor do |*|
+        'https://example.com/actor/alice'
+      end
+
+      expose :content do |*|
+        "What's up?"
+      end
+    end
+  end
+
+  let(:entity_class) { transitive_entity_class }
+
+  shared_examples_for 'activity document' do
+    it 'belongs to the ActivityStreams namespace' do
+      expect(serializer['@context']).to eq 'https://www.w3.org/ns/activitystreams'
+    end
+
+    it 'has a unique identifier' do
+      expect(serializer).to have_key 'id'
+    end
+
+    it 'has a type' do
+      expect(serializer).to have_key 'type'
+    end
+
+    it 'has an actor' do
+      expect(serializer['actor']).to eq 'https://example.com/actor/alice'
+    end
+  end
+
+  before do
+    implementer_class.entity entity_class
+  end
+
+  context 'with a valid represented entity' do
+    it_behaves_like 'activity document'
+  end
+
+  context 'when the represented entity provides no identifier' do
+    before do
+      allow(entity_class).to receive(:represent).and_return({ type: 'Person', actor: 'http://something/' })
+    end
+
+    it 'raises an exception' do
+      expect { serializer }.to raise_error(ActivityPub::ActivitySerializer::MissingIdentifierError)
+    end
+  end
+
+  context 'when the represented entity provides no type' do
+    before do
+      allow(entity_class).to receive(:represent).and_return({
+        id: 'http://something/',
+        actor: 'http://something-else/'
+      })
+    end
+
+    it 'raises an exception' do
+      expect { serializer }.to raise_error(ActivityPub::ActivitySerializer::MissingTypeError)
+    end
+  end
+
+  context 'when the represented entity provides no actor' do
+    before do
+      allow(entity_class).to receive(:represent).and_return({ id: 'http://something/', type: 'Person' })
+    end
+
+    it 'raises an exception' do
+      expect { serializer }.to raise_error(ActivityPub::ActivitySerializer::MissingActorError)
+    end
+  end
+
+  context 'when the represented entity provides no object' do
+    let(:entity_class) { intransitive_entity_class }
+
+    context 'when the caller provides the :intransitive option' do
+      let(:serializer) { implementer_class.new.represent(resource, intransitive: true) }
+
+      it_behaves_like 'activity document'
+    end
+
+    context 'when the caller does not provide the :intransitive option' do
+      it 'raises an exception' do
+        expect { serializer }.to raise_error(ActivityPub::ActivitySerializer::MissingObjectError)
+      end
+    end
+  end
+
+  context 'when the caller does provide the :intransitive option and an object' do
+    let(:serializer) { implementer_class.new.represent(resource, intransitive: true) }
+
+    it 'raises an exception' do
+      expect { serializer }.to raise_error(ActivityPub::ActivitySerializer::IntransitiveWithObjectError)
+    end
+  end
+end