[Mojo] Make javascript enums extensible.

mojo/public/js/validator.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 define("mojo/public/js/validator", [
   "mojo/public/js/codec",
 ], function(codec) {
 
   var validationError = {
     NONE: 'VALIDATION_ERROR_NONE',
     MISALIGNED_OBJECT: 'VALIDATION_ERROR_MISALIGNED_OBJECT',
     ILLEGAL_MEMORY_RANGE: 'VALIDATION_ERROR_ILLEGAL_MEMORY_RANGE',
     UNEXPECTED_STRUCT_HEADER: 'VALIDATION_ERROR_UNEXPECTED_STRUCT_HEADER',
     UNEXPECTED_ARRAY_HEADER: 'VALIDATION_ERROR_UNEXPECTED_ARRAY_HEADER',
     ILLEGAL_HANDLE: 'VALIDATION_ERROR_ILLEGAL_HANDLE',
     UNEXPECTED_INVALID_HANDLE: 'VALIDATION_ERROR_UNEXPECTED_INVALID_HANDLE',
     ILLEGAL_POINTER: 'VALIDATION_ERROR_ILLEGAL_POINTER',
     UNEXPECTED_NULL_POINTER: 'VALIDATION_ERROR_UNEXPECTED_NULL_POINTER',
     MESSAGE_HEADER_INVALID_FLAGS:
         'VALIDATION_ERROR_MESSAGE_HEADER_INVALID_FLAGS',
     MESSAGE_HEADER_MISSING_REQUEST_ID:
         'VALIDATION_ERROR_MESSAGE_HEADER_MISSING_REQUEST_ID',
     DIFFERENT_SIZED_ARRAYS_IN_MAP:
         'VALIDATION_ERROR_DIFFERENT_SIZED_ARRAYS_IN_MAP',
     INVALID_UNION_SIZE: 'VALIDATION_ERROR_INVALID_UNION_SIZE',
     UNEXPECTED_NULL_UNION: 'VALIDATION_ERROR_UNEXPECTED_NULL_UNION',
+    UNKNOWN_ENUM_VALUE: 'VALIDATION_ERROR_UNKNOWN_ENUM_VALUE',
   };
 
   var NULL_MOJO_POINTER = "NULL_MOJO_POINTER";
 
+  function isEnumClass(cls) {
+    return cls instanceof codec.Enum;
+  }
+
   function isStringClass(cls) {
     return cls === codec.String || cls === codec.NullableString;
   }
 
   function isHandleClass(cls) {
     return cls === codec.Handle || cls === codec.NullableHandle;
   }
 
   function isInterfaceClass(cls) {
     return cls === codec.Interface || cls === codec.NullableInterface;
@@ skipping 50 matching lines @@
       return true;
 
     if (index < this.handleIndex || index >= this.handleIndexLimit)
       return false;
 
     // This is safe because handle indices are uint32.
     this.handleIndex = index + 1;
     return true;
   }
 
+  Validator.prototype.validateEnum = function(offset, enumClass, nullable) {
+    // Note: Assumes that enums are always 32 bits! But this matches
+    // mojom::generate::pack::PackedField::GetSizeForKind, so it should be okay.
+    var value = this.message.buffer.getInt32(offset);
+    return enumClass.validate(value);
+  }
+
   Validator.prototype.validateHandle = function(offset, nullable) {
     var index = this.message.buffer.getUint32(offset);
 
     if (index === codec.kEncodedInvalidHandleValue)
       return nullable ?
           validationError.NONE : validationError.UNEXPECTED_INVALID_HANDLE;
 
     if (!this.claimHandle(index))
       return validationError.ILLEGAL_HANDLE;
     return validationError.NONE;
@@ skipping 229 matching lines @@
     if (isStringClass(elementType))
       return this.validateArrayElements(
           elementsOffset, numElements, codec.Uint8, nullable, [0], 0);
     if (elementType instanceof codec.PointerTo)
       return this.validateStructElements(
           elementsOffset, numElements, elementType.cls, nullable);
     if (elementType instanceof codec.ArrayOf)
       return this.validateArrayElements(
           elementsOffset, numElements, elementType.cls, nullable,
           expectedDimensionSizes, currentDimension + 1);
+    if (isEnumClass(elementType))
+      return this.validateEnum(elementsOffset, elementType.cls, nullable);
 
     return validationError.NONE;
   }
 
   // Note: the |offset + i * elementSize| computation in the validateFooElements
   // methods below is "safe" because elementSize <= 8, offset and
   // numElements are uint32, and 0 <= i < numElements.
 
   Validator.prototype.validateHandleElements =
       function(offset, numElements, nullable) {
@@ skipping 46 matching lines @@
         return err;
     }
     return validationError.NONE;
   }
 
   var exports = {};
   exports.validationError = validationError;
   exports.Validator = Validator;
   return exports;
 });