summaryrefslogtreecommitdiff
path: root/Userland/Libraries/LibJS/Runtime/ProxyConstructor.cpp
blob: 824b28eb17ceb78baf64995a944f9308c6745f4d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
/*
 * Copyright (c) 2020, Matthew Olsson <mattco@serenityos.org>
 * Copyright (c) 2021, Linus Groh <linusg@serenityos.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <LibJS/Runtime/Array.h>
#include <LibJS/Runtime/Error.h>
#include <LibJS/Runtime/GlobalObject.h>
#include <LibJS/Runtime/ProxyConstructor.h>
#include <LibJS/Runtime/ProxyObject.h>

namespace JS {

// 10.5.14 ProxyCreate ( target, handler ), https://tc39.es/ecma262/#sec-proxycreate
static ProxyObject* proxy_create(GlobalObject& global_object, Value target, Value handler)
{
    auto& vm = global_object.vm();
    if (!target.is_object()) {
        vm.throw_exception<TypeError>(global_object, ErrorType::ProxyConstructorBadType, "target", target.to_string_without_side_effects());
        return {};
    }
    if (!handler.is_object()) {
        vm.throw_exception<TypeError>(global_object, ErrorType::ProxyConstructorBadType, "handler", handler.to_string_without_side_effects());
        return {};
    }
    return ProxyObject::create(global_object, target.as_object(), handler.as_object());
}

ProxyConstructor::ProxyConstructor(GlobalObject& global_object)
    : NativeFunction(vm().names.Proxy.as_string(), *global_object.function_prototype())
{
}

void ProxyConstructor::initialize(GlobalObject& global_object)
{
    auto& vm = this->vm();
    NativeFunction::initialize(global_object);
    define_direct_property(vm.names.length, Value(2), Attribute::Configurable);
    u8 attr = Attribute::Writable | Attribute::Configurable;
    define_native_function(vm.names.revocable, revocable, 2, attr);
}

ProxyConstructor::~ProxyConstructor()
{
}

// 28.2.1.1 Proxy ( target, handler ), https://tc39.es/ecma262/#sec-proxy-target-handler
Value ProxyConstructor::call()
{
    auto& vm = this->vm();
    vm.throw_exception<TypeError>(global_object(), ErrorType::ConstructorWithoutNew, vm.names.Proxy);
    return {};
}

// 28.2.1.1 Proxy ( target, handler ), https://tc39.es/ecma262/#sec-proxy-target-handler
Value ProxyConstructor::construct(FunctionObject&)
{
    auto& vm = this->vm();
    return proxy_create(global_object(), vm.argument(0), vm.argument(1));
}

// 28.2.2.1 Proxy.revocable ( target, handler ), https://tc39.es/ecma262/#sec-proxy.revocable
JS_DEFINE_NATIVE_FUNCTION(ProxyConstructor::revocable)
{
    auto* proxy = proxy_create(global_object, vm.argument(0), vm.argument(1));
    if (vm.exception())
        return {};

    // 28.2.2.1.1 Proxy Revocation Functions, https://tc39.es/ecma262/#sec-proxy-revocation-functions
    auto* revoker = NativeFunction::create(global_object, "", [proxy_handle = make_handle(proxy)](auto&, auto&) -> Value {
        auto& proxy = const_cast<ProxyObject&>(*proxy_handle.cell());
        if (proxy.is_revoked())
            return js_undefined();
        // NOTE: The spec wants us to unset [[ProxyTarget]] and [[ProxyHandler]],
        // which is their way of revoking the Proxy - this might affect GC-ability,
        // but AFAICT not doing that should be ok compatibility-wise.
        proxy.revoke();
        return js_undefined();
    });
    revoker->define_direct_property(vm.names.length, Value(0), Attribute::Configurable);

    auto* result = Object::create(global_object, global_object.object_prototype());
    result->create_data_property_or_throw(vm.names.proxy, proxy);
    result->create_data_property_or_throw(vm.names.revoke, revoker);
    return result;
}

}