fix: supporte moving default lists for xml parser (#3087)

* fix: supporte moving default lists for xml parser

Currently for all xml service, the parser inserts empty
array [] when a list member doesn't exist in xml string.
It was introduced long ago: eae5b32
This change introduce a new key in metadata called
xmlNoDefaultLists. If set to true, xml parser will not
try to insert default empty array if the member doesn't
exist. This key is only applicable to rest-xml, query
protocol services.

.changes/next-release/bugfix-parser-5e14f8ef.json

@@ -0,0 +1,5 @@
+{
+  "type": "bugfix",
+  "category": "parser",
+  "description": "Now we can disable inserting empty array in xml parser if the member doesn't exist in response."
+}

apis/metadata.json

@@ -360,7 +360,8 @@
   },
   "s3control": {
     "name": "S3Control",
-    "dualstackAvailable": true
+    "dualstackAvailable": true,
+    "xmlNoDefaultLists": true
   },
   "servicecatalog": {
     "name": "ServiceCatalog",

lib/model/api.js

@@ -3,6 +3,7 @@ var Operation = require('./operation');
 var Shape = require('./shape');
 var Paginator = require('./paginator');
 var ResourceWaiter = require('./resource_waiter');
+var metadata = require('../../apis/metadata.json');
 
 var util = require('../util');
 var property = util.property;
@@ -16,6 +17,9 @@ function Api(api, options) {
 
   api.metadata = api.metadata || {};
 
+  var serviceIdentifier = options.serviceIdentifier;
+  delete options.serviceIdentifier;
+
   property(this, 'isApi', true, false);
   property(this, 'apiVersion', api.metadata.apiVersion);
   property(this, 'endpointPrefix', api.metadata.endpointPrefix);
@@ -30,6 +34,9 @@ function Api(api, options) {
   property(this, 'abbreviation', api.metadata.serviceAbbreviation);
   property(this, 'fullName', api.metadata.serviceFullName);
   property(this, 'serviceId', api.metadata.serviceId);
+  if (serviceIdentifier) {
+      property(this, 'xmlNoDefaultLists', metadata[serviceIdentifier].xmlNoDefaultLists, false);
+  }
 
   memoizedProperty(this, 'className', function() {
     var name = api.metadata.serviceAbbreviation || api.metadata.serviceFullName;

lib/service.js

@@ -751,7 +751,9 @@ AWS.util.update(AWS.Service, {
       if (api.isApi) {
         svc.prototype.api = api;
       } else {
-        svc.prototype.api = new Api(api);
+        svc.prototype.api = new Api(api, {
+          serviceIdentifier: superclass.serviceIdentifier
+        });
       }
     }
 

lib/xml/browser_parser.js

@@ -108,7 +108,10 @@ function parseStructure(xml, shape) {
         getElementByTagName(xml, memberShape.name);
       if (xmlChild) {
         data[memberName] = parseXml(xmlChild, memberShape);
-      } else if (!memberShape.flattened && memberShape.type === 'list') {
+      } else if (
+        !memberShape.flattened &&
+        memberShape.type === 'list' &&
+        !shape.api.xmlNoDefaultLists) {
         data[memberName] = memberShape.defaultValue;
       }
     }

lib/xml/node_parser.js

@@ -70,7 +70,7 @@ function parseStructure(xml, shape) {
     } else if (memberShape.isXmlAttribute &&
                xml.$ && Object.prototype.hasOwnProperty.call(xml.$, xmlName)) {
       data[memberName] = parseScalar(xml.$[xmlName], memberShape);
-    } else if (memberShape.type === 'list') {
+    } else if (memberShape.type === 'list' && !shape.api.xmlNoDefaultLists) {
       data[memberName] = memberShape.defaultValue;
     }
   });