[WIP] Ensure references_many no nil value

lib/ledger_sync/serialization/type/deserializer_references_many_type.rb

@@ -11,7 +11,7 @@ def cast_value(args = {})
           value                  = args.fetch(:value)
           resource               = args.fetch(:resource)
 
-          return if value.nil?
+          return [] if value.nil?
 
           first_dot = deserializer_attribute.resource_attribute_dot_parts.first.to_sym
           nested_resource = resource.class.resource_attributes[first_dot].type.resource_class.new

lib/ledger_sync/type/value_mixin.rb

@@ -22,7 +22,6 @@ def assert_valid(args = {})
       # Do not override this method.  Override private method cast_value
       def cast(args = {})
         assert_valid(args)
-        return nil if args.fetch(:value).nil?
 
         cast_value(args)
       end

spec/deserializer/acceptance_artifact_spec.rb

@@ -0,0 +1,65 @@
+# Usage: bundle exec rspec spec/deserializer/acceptance_artifact_spec.rb
+
+require 'ledger_sync'
+require 'rspec'
+
+class Package < LedgerSync::Resource
+  attribute :blabla, type: LedgerSync::Type::String
+end
+
+class Package
+  class Deserializer < LedgerSync::Deserializer
+    attribute :blabla, hash_attribute: :blabla
+  end
+end
+
+class AcceptanceArtifact < LedgerSync::Resource
+  attribute :identifier, type: LedgerSync::Type::String
+  references_many :packages, to: Package
+end
+
+class AcceptanceArtifact
+  class Deserializer < LedgerSync::Deserializer
+    attribute :identifier, hash_attribute: :identifier
+    references_many :packages, deserializer: Package::Deserializer,  hash_attribute: :packages
+  end
+end
+
+RSpec.describe AcceptanceArtifact::Deserializer do
+  describe '#deserialize' do
+    let(:deserializer) { described_class.new }
+    let(:acceptance_artifact) { AcceptanceArtifact.new }
+
+    subject(:deserialized_object) { deserializer.deserialize(hash: response, resource: acceptance_artifact) }
+
+    context "with empty `packages` in the API's response" do
+      let(:response) { { "identifier" => "42", "packages" => [] } }
+
+      it 'deserializes the identifier correctly' do
+        expect(deserialized_object.identifier).to eq("42")
+      end
+    end
+
+    context "with filled `packages` in the API's response" do
+      let(:response) { { "identifier" => "42", "packages" => [ { "blabla" => "ok" } ] } }
+
+      it 'deserializes the identifier correctly' do
+        expect(deserialized_object.identifier).to eq("42")
+      end
+    end
+
+    context "without `packages` in the API's response" do
+      let(:response) { { "identifier" => "42" } }
+
+      it 'deserializes the packages correctly' do
+        expect(deserialized_object.packages).to eq([])
+      end
+    end
+  end
+end
+
+# Manual trigger
+# deserializer = AcceptanceArtifact::Deserializer.new
+# response_1 = { "identifier" => "42", "packages" => [] }
+# response_2 = { "identifier" => "42" }
+# accept_art = deserializer.deserialize(hash: response_1, resource: AcceptanceArtifact.new)