Skip missing attributes when encrypting/decrypting event's payload

ruby_event_store/lib/ruby_event_store/mappers/transformation/encryption.rb

@@ -82,14 +82,14 @@ def encryption_metadata(data, schema)
 
         def encrypt_data(data, meta)
           meta.reduce(data) do |acc, (key, value)|
-            acc[key] = encrypt_attribute(acc, key, value)
+            acc[key] = encrypt_attribute(acc, key, value) if data.has_key?(key)
             acc
           end
         end
 
         def decrypt_data(data, meta)
           meta.reduce(data) do |acc, (key, value)|
-            acc[key] = decrypt_attribute(data, key, value)
+            acc[key] = decrypt_attribute(data, key, value) if data.has_key?(key)
             acc
           end
         end

ruby_event_store/spec/mappers/transformation/encryption_spec.rb

@@ -115,6 +115,33 @@ def decrypt(r)
           expect(event.metadata).to eq(metadata)
         end
 
+        context "when encryptable event keys are missing" do
+           let(:sender) do
+             {
+               user_id: sender_id,
+               email: sender_email,
+               twitter: '@alice'
+             }
+           end
+
+           specify 'skip missing data keys' do
+             key_repository.create(sender_id)
+             key_repository.create(recipient_id)
+
+             event = decrypt(encrypt(ticket_transferred))
+
+             expect(event.event_id).to eq(event_id)
+
+             expect(event.data).to eq({
+               ticket_id: ticket_id,
+               sender: sender,
+               recipient: recipient
+             })
+
+             expect(event.metadata).to eq(metadata)
+           end
+         end
+
         specify 'obfuscates data for missing keys on decryption' do
           key_repository.create(sender_id)
           key_repository.create(recipient_id)