Add tests for computed __proto__ property keys (#916)

Fixes #904

test/annexB/language/expressions/object/__proto__-duplicate-computed.js

+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-__proto__-property-names-in-object-initializers
+es6id: B.3.1
+description: >
+    The syntax error for duplicate `__proto__` property is not valid if the duplicate is a
+    ComputedPropertyName
+info: |
+    B.3.1__proto__ Property Names in Object Initializers
+
+    It is a Syntax Error if PropertyNameList of PropertyDefinitionList contains any duplicate
+    entries for  "__proto__" and at least two of those entries were obtained from productions of
+    the form
+    PropertyDefinition : PropertyName : AssignmentExpression .
+
+    12.2.6.6 Static Semantics: PropertyNameList
+
+    ...
+    3. Append PropName of PropertyDefinition to the end of list.
+    ...
+
+    12.2.6.5 Static Semantics: PropName
+
+    ComputedPropertyName : [ AssignmentExpression ]
+        1. Return empty.
+---*/
+
+var obj;
+var proto = {};
+var ownProp = {};
+
+obj = {
+    __proto__: proto,
+    ['__proto__']: {},
+    ['__proto__']: ownProp
+};
+
+assert.sameValue(
+    Object.getPrototypeOf(obj),
+    proto,
+    'prototype is defined'
+);
+
+assert(
+    Object.hasOwnProperty.call(obj, '__proto__'),
+    'has own property __proto__'
+);
+
+assert.sameValue(
+    obj.__proto__,
+    ownProp,
+    'own property value'
+);

test/language/expressions/object/computed-__proto__.js

+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: prod-PropertyDefinition
+description: >
+  computed __proto__ property key is assigned to an own property
+info: |
+  12.2.6 Object Initializer
+
+  PropertyDefinition[Yield, Await] :
+    PropertyName[?Yield, ?Await] : AssignmentExpression[+In, ?Yield, ?Await]
+
+  PropertyName[Yield, Await] :
+    LiteralPropertyName
+    ComputedPropertyName[?Yield, ?Await]
+
+  ComputedPropertyName[Yield, Await] :
+    [ AssignmentExpression[+In, ?Yield, ?Await] ]
+
+  B.3.1__proto__ Property Names in Object Initializers
+
+  ...
+  5. If propKey is the String value "__proto__" and if IsComputedPropertyKey(propKey)
+    is false, then
+    a. If Type(propValue) is either Object or Null, then
+        i. Return object.[[SetPrototypeOf]](propValue).
+    b. Return NormalCompletion(empty).
+---*/
+
+var obj;
+var sample = {};
+
+obj = {
+  ['__proto__']: sample
+};
+assert.sameValue(
+  Object.getPrototypeOf(obj),
+  Object.prototype,
+  'does not change the object prototype (ordinary object)'
+);
+assert(
+  obj.hasOwnProperty('__proto__'),
+  'computed __proto__ property is set as an own property (ordinary object)'
+);
+assert.sameValue(
+  obj.__proto__,
+  sample,
+  'value is properly defined (ordinary object)'
+);
+
+obj = {
+  ['__proto__']: null
+};
+assert.sameValue(
+  Object.getPrototypeOf(obj),
+  Object.prototype,
+  'does not change the object prototype (null)'
+);
+assert(
+  obj.hasOwnProperty('__proto__'),
+  'computed __proto__ property is set as an own property (null)'
+);
+assert.sameValue(
+  obj.__proto__,
+  null,
+  'value is properly defined (null)'
+);
+
+obj = {
+  ['__proto__']: undefined
+};
+assert.sameValue(
+  Object.getPrototypeOf(obj),
+  Object.prototype,
+  'does not change the object prototype (undefined)'
+);
+assert(
+  obj.hasOwnProperty('__proto__'),
+  'computed __proto__ property is set as an own property (undefined)'
+);
+assert.sameValue(
+  obj.__proto__,
+  undefined,
+  'value is properly defined (undefined)'
+);
+
+var func = function() {};
+obj = {
+  ['__proto__']: func
+};
+assert.sameValue(
+  Object.getPrototypeOf(obj),
+  Object.prototype,
+  'does not change the object prototype (func)'
+);
+assert(
+  obj.hasOwnProperty('__proto__'),
+  'computed __proto__ property is set as an own property (func)'
+);
+assert.sameValue(
+  obj.__proto__,
+  func,
+  'value is properly defined (func)'
+);
+
+var symbol = Symbol('Leo');
+obj = {
+  ['__proto__']: symbol
+};
+assert.sameValue(
+  Object.getPrototypeOf(obj),
+  Object.prototype,
+  'does not change the object prototype (symbol)'
+);
+assert(
+  obj.hasOwnProperty('__proto__'),
+  'computed __proto__ property is set as an own property (symbol)'
+);
+assert.sameValue(
+  obj.__proto__,
+  symbol,
+  'value is properly defined (symbol)'
+);
+
+obj = {
+  ['__proto__']: 42
+};
+assert.sameValue(
+  Object.getPrototypeOf(obj),
+  Object.prototype,
+  'does not change the object prototype (number)'
+);
+assert(
+  obj.hasOwnProperty('__proto__'),
+  'computed __proto__ property is set as an own property (number)'
+);
+assert.sameValue(
+  obj.__proto__,
+  42,
+  'value is properly defined (number)'
+);
+
+obj = {
+  ['__proto__']: ''
+};
+assert.sameValue(
+  Object.getPrototypeOf(obj),
+  Object.prototype,
+  'does not change the object prototype (string)'
+);
+assert(
+  obj.hasOwnProperty('__proto__'),
+  'computed __proto__ property is set as an own property (string)'
+);
+assert.sameValue(
+  obj.__proto__,
+  '',
+  'value is properly defined (string)'
+);
+
+obj = {
+  ['__proto__']: false
+};
+assert.sameValue(
+  Object.getPrototypeOf(obj),
+  Object.prototype,
+  'does not change the object prototype (boolean)'
+);
+assert(
+  obj.hasOwnProperty('__proto__'),
+  'computed __proto__ property is set as an own property (boolean)'
+);
+assert.sameValue(
+  obj.__proto__,
+  false,
+  'value is properly defined (boolean)'
+);