turn Storages::FileLinks::CreateContract into a ModelContract

+ display more information in test if there are contract errors

modules/storages/app/contracts/storages/file_links/create_contract.rb

@@ -26,7 +26,21 @@
 # See COPYRIGHT and LICENSE files for more details.
 #++
 
-class Storages::FileLinks::CreateContract < BaseContract
+class Storages::FileLinks::CreateContract < ModelContract
+  attribute :name
+  attribute :storage
+  attribute :creator
+  attribute :container
+  attribute :container_type
+
+  attribute :origin_id
+  attribute :origin_name
+  attribute :origin_created_by_name
+  attribute :origin_last_modified_by_name
+  attribute :origin_mime_type
+  attribute :origin_created_at
+  attribute :origin_updated_at
+
   validate :validate_storage_presence
   validate :validate_user_allowed_to_manage
   validate :validate_project_storage_link

spec/requests/api/v3/support/api_v3_collection_response.rb

@@ -60,6 +60,13 @@ shared_examples_for 'API V3 collection response' do |total, count, element_type,
   it 'returns a collection successfully' do
     aggregate_failures do
       expect(last_response.status).to eq(expected_status_code)
+      errors = JSON.parse(subject).dig("_embedded", "errors")&.map { _1["message"] }
+      expect(errors).to eq([]) if errors # make errors visible in console if any
+    end
+  end
+
+  it 'contains all elements' do
+    aggregate_failures do
       expect(subject).to be_json_eql(collection_type.to_json).at_path('_type')
       expect(subject).to be_json_eql(count_number.to_json).at_path('count')
       expect(subject).to be_json_eql(total_number.to_json).at_path('total')