Add missing fields to Upload Fabricator (#6448)

spec/fabricators/upload_fabricator.rb

@@ -5,6 +5,8 @@ Fabricator(:upload) do
   filesize 1234
   width 100
   height 200
+  thumbnail_width 30
+  thumbnail_height 60
 
   url do |attrs|
     sequence(:url) do |n|

spec/serializers/upload_serializer_spec.rb

@@ -0,0 +1,16 @@
+require 'rails_helper'
+
+RSpec.describe UploadSerializer do
+  let(:upload) { Fabricate(:upload) }
+  let(:subject) { UploadSerializer.new(upload, root: false) }
+
+  it 'should render without errors' do
+    json_data = JSON.load(subject.to_json)
+
+    expect(json_data['id']).to eql upload.id
+    expect(json_data['width']).to eql upload.width
+    expect(json_data['height']).to eql upload.height
+    expect(json_data['thumbnail_width']).to eql upload.thumbnail_width
+    expect(json_data['thumbnail_height']).to eql upload.thumbnail_height
+  end
+end