Apply requiredOnly option; fixes #81

ts/class/OptionRegistry.ts

@@ -12,6 +12,7 @@ class OptionRegistry extends Registry<Option> {
     this.data['failOnInvalidTypes'] = true;
     this.data['defaultInvalidTypeProduct'] = null;
     this.data['useDefaultValue'] = false;
+    this.data['requiredOnly'] = false;
     this.data['maxItems'] = null;
     this.data['maxLength'] = null;
     this.data['defaultMinItems'] = 0;

ts/types/object.ts

@@ -35,6 +35,16 @@ var objectType: FTypeGenerator = function objectType(value: IObjectSchema, path,
         throw new ParseError('missing properties for:\n' + JSON.stringify(value, null, '  '), path);
     }
 
+    if (option('requiredOnly') === true) {
+        requiredProperties.forEach(function(key) {
+            if (properties[key]) {
+                props[key] = properties[key];
+            }
+        });
+
+        return traverseCallback(props, path.concat(['properties']), resolve);
+    }
+
     var min = Math.max(value.minProperties || 0, requiredProperties.length);
     var max = Math.max(value.maxProperties || random.number(min, min + 5));