Add QuoteSerializer

app/serializers/rest/quote_serializer.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class REST::QuoteSerializer < ActiveModel::Serializer
+  attributes :state
+
+  has_one :quoted_status, serializer: REST::ShallowStatusSerializer
+
+  def quoted_status
+    object.quoted_status if object.accepted?
+  end
+end

app/serializers/rest/shallow_quote_serializer.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class REST::ShallowQuoteSerializer < ActiveModel::Serializer
+  attributes :state, :quoted_status_id
+
+  def quoted_status_id
+    object.quoted_status&.id&.to_s if object.accepted?
+  end
+end

app/serializers/rest/shallow_status_serializer.rb

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+class REST::ShallowStatusSerializer < REST::StatusSerializer
+  # It looks like defining one `has_one` requires redefining all of them
+  has_one :quote, key: :quote, serializer: REST::ShallowQuoteSerializer
+  has_one :preview_card, key: :card, serializer: REST::PreviewCardSerializer
+  has_one :preloadable_poll, key: :poll, serializer: REST::PollSerializer
+end

app/serializers/rest/status_serializer.rb

@@ -29,6 +29,7 @@ class REST::StatusSerializer < ActiveModel::Serializer
   has_many :tags
   has_many :emojis, serializer: REST::CustomEmojiSerializer
 
+  has_one :quote, key: :quote, serializer: REST::QuoteSerializer
   has_one :preview_card, key: :card, serializer: REST::PreviewCardSerializer
   has_one :preloadable_poll, key: :poll, serializer: REST::PollSerializer
 

spec/serializers/rest/quote_serializer_spec.rb

@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe REST::QuoteSerializer do
+  subject do
+    serialized_record_json(
+      quote,
+      described_class,
+      options: {
+        scope: current_user,
+        scope_name: :current_user,
+      }
+    )
+  end
+
+  let(:current_user) { Fabricate(:user) }
+  let(:quote) { Fabricate(:quote) }
+
+  context 'with a pending quote' do
+    it 'returns expected values' do
+      expect(subject.deep_symbolize_keys)
+        .to include(
+          quoted_status: nil,
+          state: 'pending'
+        )
+    end
+  end
+
+  context 'with an accepted quote' do
+    let(:quote) { Fabricate(:quote, state: :accepted) }
+
+    it 'returns expected values' do
+      expect(subject.deep_symbolize_keys)
+        .to include(
+          quoted_status: be_a(Hash),
+          state: 'accepted'
+        )
+    end
+  end
+
+  context 'with a recursive accepted quote' do
+    let(:status) { Fabricate(:status) }
+    let(:quote) { Fabricate(:quote, status: status, quoted_status: status, state: :accepted) }
+
+    it 'returns expected values' do
+      expect(subject.deep_symbolize_keys)
+        .to include(
+          quoted_status: be_a(Hash),
+          state: 'accepted'
+        )
+    end
+  end
+end