Modifying the es5 and es6 templates for javascript to handle default values (#6649)

for required fields better. This change ensures the required field isn't
overridden with undefined when the object is constructed - especially through
a chain of constructFromObject calls..

modules/openapi-generator/src/main/resources/Javascript/es6/partial_model_generic.mustache

@@ -26,7 +26,7 @@ class {{classname}} {{#parent}}{{^parentModel}}{{#vendorExtensions.x-is-array}}e
      * Only for internal use.
      */{{/emitJSDoc}}
     static initialize(obj{{#vendorExtensions.x-all-required}}, {{name}}{{/vendorExtensions.x-all-required}}) { {{#vars}}{{#required}}
-        obj['{{baseName}}'] = {{name}};{{/required}}{{/vars}}
+        {{#defaultValue}}obj['{{baseName}}'] = {{name}} || {{{defaultValue}}};{{/defaultValue}}{{^defaultValue}}obj['{{baseName}}'] = {{name}};{{/defaultValue}}{{/required}}{{/vars}}
     }
 
     {{#emitJSDoc}}/**

modules/openapi-generator/src/main/resources/Javascript/partial_model_generic.mustache

@@ -33,7 +33,12 @@
     {{/useInheritance}}
     {{#vars}}
     {{#required}}
+    {{#defaultValue}}
+    _this['{{baseName}}'] = {{name}} || {{{defaultValue}}};
+    {{/defaultValue}}
+    {{^defaultValue}}
     _this['{{baseName}}'] = {{name}};
+    {{/defaultValue}}
     {{/required}}
     {{/vars}}
     {{#parent}}

samples/client/petstore/javascript-es6/src/model/Category.js

@@ -35,7 +35,7 @@ class Category {
      * Only for internal use.
      */
     static initialize(obj, name) { 
-        obj['name'] = name;
+        obj['name'] = name || 'default-name';
     }
 
     /**

samples/client/petstore/javascript-promise-es6/src/model/Category.js

@@ -35,7 +35,7 @@ class Category {
      * Only for internal use.
      */
     static initialize(obj, name) { 
-        obj['name'] = name;
+        obj['name'] = name || 'default-name';
     }
 
     /**