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Implement Object.freeze and Object.isFrozen function #202

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136 changes: 132 additions & 4 deletions jerry-core/ecma/builtin-objects/ecma-builtin-object.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -259,10 +259,82 @@ ecma_builtin_object_object_seal (ecma_value_t this_arg __attr_unused___, /**< 't
* Returned value must be freed with ecma_free_completion_value.
*/
static ecma_completion_value_t
ecma_builtin_object_object_freeze (ecma_value_t this_arg, /**< 'this' argument */
ecma_builtin_object_object_freeze (ecma_value_t this_arg __attr_unused___, /**< 'this' argument */
ecma_value_t arg) /**< routine's argument */
{
ECMA_BUILTIN_CP_UNIMPLEMENTED (this_arg, arg);
ecma_completion_value_t ret_value = ecma_make_empty_completion_value ();

// 1.
if (!ecma_is_value_object (arg))
{
ret_value = ecma_make_throw_obj_completion_value (ecma_new_standard_error (ECMA_ERROR_TYPE));
}
else
{
// 2.
ecma_object_t *obj_p = ecma_get_object_from_value (arg);

ecma_property_t *property_p;
for (property_p = ecma_get_property_list (obj_p);
property_p != NULL && ecma_is_completion_value_empty (ret_value);
property_p = ECMA_GET_POINTER (ecma_property_t, property_p->next_property_p))
{
ecma_string_t *property_name_p;

if (property_p->type == ECMA_PROPERTY_NAMEDDATA)
{
property_name_p = ECMA_GET_NON_NULL_POINTER (ecma_string_t,
property_p->u.named_data_property.name_p);
}
else
if (property_p->type == ECMA_PROPERTY_NAMEDACCESSOR)
{
property_name_p = ECMA_GET_NON_NULL_POINTER (ecma_string_t,
property_p->u.named_accessor_property.name_p);
}
else
{
continue;
}

// 2.a
ecma_property_descriptor_t prop_desc = ecma_get_property_descriptor_from_property (property_p);

// 2.b
if (property_p->type == ECMA_PROPERTY_NAMEDDATA && ecma_is_property_writable (property_p))
{
prop_desc.is_writable = false;
}

// 2.c
if (ecma_is_property_configurable (property_p))
{
prop_desc.is_configurable = false;
}

// 2.d
ECMA_TRY_CATCH (define_own_prop_ret,
ecma_op_object_define_own_property (obj_p,
property_name_p,
&prop_desc,
true),
ret_value);
ECMA_FINALIZE (define_own_prop_ret);

ecma_free_property_descriptor (&prop_desc);
}

if (ecma_is_completion_value_empty (ret_value))
{
// 3.
ecma_set_object_extensible (obj_p, false);

// 4.
ret_value = ecma_make_normal_completion_value (ecma_copy_value (arg, true));
}
}

return ret_value;
} /* ecma_builtin_object_object_freeze */

/**
Expand Down Expand Up @@ -370,10 +442,66 @@ ecma_builtin_object_object_is_sealed (ecma_value_t this_arg __attr_unused___, /*
* Returned value must be freed with ecma_free_completion_value.
*/
static ecma_completion_value_t
ecma_builtin_object_object_is_frozen (ecma_value_t this_arg, /**< 'this' argument */
ecma_builtin_object_object_is_frozen (ecma_value_t this_arg __attr_unused___, /**< 'this' argument */
ecma_value_t arg) /**< routine's argument */
{
ECMA_BUILTIN_CP_UNIMPLEMENTED (this_arg, arg);
ecma_completion_value_t ret_value = ecma_make_empty_completion_value ();

// 1.
if (!ecma_is_value_object (arg))
{
ret_value = ecma_make_throw_obj_completion_value (ecma_new_standard_error (ECMA_ERROR_TYPE));
}
else
{
ecma_object_t *obj_p = ecma_get_object_from_value (arg);
ecma_property_t *property_p;

// This will be the result if the other steps doesn't change it.
bool frozen = false;

// 3.
// The pseudo code contains multiple early return but this way we get the same
// result.
if (!ecma_get_object_extensible (obj_p))
{
frozen = true;
}

// 2.
for (property_p = ecma_get_property_list (obj_p);
property_p != NULL && frozen;
property_p = ECMA_GET_POINTER (ecma_property_t, property_p->next_property_p))
{
if (property_p->type == ECMA_PROPERTY_INTERNAL)
{
continue;
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Could you, please, add assertion that property type is one of the types handled in the loop?

}

JERRY_ASSERT (property_p->type == ECMA_PROPERTY_NAMEDDATA || property_p->type == ECMA_PROPERTY_NAMEDACCESSOR);

// 2.b
if (property_p->type == ECMA_PROPERTY_NAMEDDATA && ecma_is_property_writable (property_p))
{
frozen = false;
break;
}

// 2.c
if (ecma_is_property_configurable (property_p))
{
frozen = false;
break;
}
}

// 4.
ret_value = ecma_make_simple_completion_value (frozen
? ECMA_SIMPLE_VALUE_TRUE
: ECMA_SIMPLE_VALUE_FALSE);
}

return ret_value;
} /* ecma_builtin_object_object_is_frozen */

/**
Expand Down
5 changes: 2 additions & 3 deletions tests/jerry/object-is-extensible.js
Original file line number Diff line number Diff line change
Expand Up @@ -42,7 +42,6 @@ try
var sealed = Object.seal({});
assert (Object.isExtensible(sealed) === false);

// The functions below are unimplemented.
// Frozen objects are also by definition non-extensible.
// var frozen = Object.freeze({});
// assert(Object.isExtensible(frozen) === false);
var frozen = Object.freeze({});
assert(Object.isExtensible(frozen) === false);
79 changes: 79 additions & 0 deletions tests/jerry/object_freeze.js
Original file line number Diff line number Diff line change
@@ -0,0 +1,79 @@
// Copyright 2015 Samsung Electronics Co., Ltd.
// Copyright 2015 University of Szeged.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

var obj = {
prop: function() {},
foo: 'bar'
};

// New properties may be added, existing properties may be changed or removed
obj.foo = 'baz';
obj.lumpy = 'woof';
delete obj.prop;

var o = Object.freeze(obj);

assert(Object.isFrozen(obj) === true);

// Now any changes will fail
obj.foo = 'quux'; // silently does nothing
assert (obj.foo === 'baz');

obj.quaxxor = 'the friendly duck'; // silently doesn't add the property
assert (obj.quaxxor === undefined);

// ...and in strict mode such attempts will throw TypeErrors
function fail(){
'use strict';

try {
obj.foo = 'sparky'; // throws a TypeError
assert (false);
} catch (e) {
assert (e instanceof TypeError);
}

try {
delete obj.foo; // throws a TypeError
assert (false);
} catch (e) {
assert (e instanceof TypeError);
}

try {
obj.sparky = 'arf'; // throws a TypeError
assert (false);
} catch (e) {
assert (e instanceof TypeError);
}
}

fail();

// Attempted changes through Object.defineProperty will also throw

try {
Object.defineProperty(obj, 'ohai', { value: 17 }); // throws a TypeError
assert (false);
} catch (e) {
assert (e instanceof TypeError);
}

try {
Object.defineProperty(obj, 'foo', { value: 'eit' }); // throws a TypeError
assert (false);
} catch (e) {
assert (e instanceof TypeError);
}