feat: SharedArrayBuffer 原型对象与构造器 meta 正式绑定

crates/oxide_builtins/src/array_buffer.rs

@@ -159,9 +159,15 @@ pub fn drop_array_buffer_native(obj: &mut JsObject) -> u64 {
     bytes
 }
 
-/// 分配定长 SharedArrayBuffer 对象（零填充字节缓冲，`max_byte_length` 存 0）。
-pub(crate) fn new_shared_array_buffer<H: VmHost>(vm: &mut H, data: Vec<u8>) -> *mut JsObject {
-    let mut obj = JsObject::new_empty(EMPTY_SHAPE_ID, JsValue::null());
+/// 默认缓冲区原型 %SharedArrayBuffer.prototype%（构造器回落路径与各定长建点共用）。
+pub(crate) fn default_shared_array_buffer_proto<H: VmHost>(vm: &H) -> JsValue {
+    JsValue::from_js_object(vm.session().builtin_world().shared_array_buffer_proto.as_ptr() as *mut JsObject)
+}
+
+/// 分配携给定 proto 与载荷形态（`max_byte_length` 恒 0 定长）的
+/// SharedArrayBuffer 对象；byteLength 经原型访问器读（不写 own 数据属性）。
+pub(crate) fn new_shared_array_buffer<H: VmHost>(vm: &mut H, data: Vec<u8>, proto: JsValue) -> *mut JsObject {
+    let mut obj = JsObject::new_empty(EMPTY_SHAPE_ID, proto);
     obj.type_tag = JsObject::OBJ_TYPE_SHARED_ARRAY_BUFFER;
     let payload = ArrayBufferPayload {
         data: Some(data),
@@ -227,8 +233,16 @@ pub fn clone_shared_array_buffer_native(old_obj: &JsObject, new_obj: &mut JsObje
 }
 
 /// `SharedArrayBuffer(length)`：构造语义仅 `new`；length 缺省 0，经 ToIndex
-/// 传播式（强转副作用原值上抛），超引擎上界 → RangeError。最小实现：字节
-/// 缓冲零填充定长，无 resizable 选项面与 `[[ArrayBufferMaxByteLength]]`。
+/// 传播式（强转副作用原值上抛），超引擎上界 → RangeError。
+///
+/// # 步骤
+/// 1. 非构造形态（普通调用，new.target 缺失）→ TypeError。
+/// 2. length = ToIndex(length) 传播式；undefined/缺省 → 0。
+/// 3. 分配期上界校验（超引擎上限 → RangeError）。
+/// 4. GetPrototypeFromConstructor：经 ordinary_get 读 new.target 的
+///    "prototype"（访问器触发，异常原值传播）；非对象结果回落
+///    %SharedArrayBuffer.prototype%。
+/// 5. 对象创建（零填充定长，无 resizable 选项面）。
 pub fn shared_array_buffer_constructor<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
     if !vm.constructing_native() {
         return NativeResult::Err(crate::error::create_type_error(vm, "SharedArrayBuffer must be called with new"));
@@ -237,10 +251,92 @@ pub fn shared_array_buffer_constructor<H: VmHost>(vm: &mut H, args: &[u8]) -> Na
     if length > MAX_ARRAY_BUFFER_LENGTH {
         return NativeResult::Err(crate::error::create_range_error(vm, "invalid SharedArrayBuffer length"));
     }
-    let obj_ptr = new_shared_array_buffer(vm, vec![0; length]);
+    // GetPrototypeFromConstructor：prototype getter 可抛错，异常原值传播；
+    // 结果非对象时回落默认原型。
+    let default_proto = default_shared_array_buffer_proto(vm);
+    let new_target = vm.reg(255);
+    let proto = if new_target.is_object() {
+        let nt_ptr = new_target.as_js_object_ptr();
+        // SAFETY: is_object 保证指针非空且对象本 session 存活。
+        let nt_obj = unsafe { &*nt_ptr };
+        let proto_si = vm.kernel_core().perm_interner().intern("prototype").0;
+        let proto_val = match vm.ordinary_get(nt_obj, proto_si, new_target) {
+            Ok(v) => v,
+            Err(err) => return NativeResult::Err(crate::iterator::engine_error(vm, &err)),
+        };
+        if proto_val.is_object() {
+            proto_val
+        } else {
+            default_proto
+        }
+    } else {
+        default_proto
+    };
+    let obj_ptr = new_shared_array_buffer(vm, vec![0; length], proto);
     NativeResult::Ok(JsValue::from_js_object(obj_ptr))
 }
 
+/// 读入口：校验 receiver 为 SharedArrayBuffer 并取载荷指针。SAB 无 detach
+/// 生产路径，载荷 `data` 恒在场（`map_or` 兜底与 AB 读入口同形）。
+pub(crate) fn shared_array_buffer_payload<H: VmHost>(
+    vm: &mut H, this_val: JsValue,
+) -> Result<*mut ArrayBufferPayload, JsValue> {
+    if !this_val.is_object() {
+        return Err(crate::error::create_type_error(
+            vm,
+            "SharedArrayBuffer method called on incompatible receiver",
+        ));
+    }
+    let obj_ptr = this_val.as_js_object_ptr();
+    if obj_ptr.is_null() {
+        return Err(crate::error::create_type_error(vm, "SharedArrayBuffer internal state invalid"));
+    }
+    let obj = unsafe { &*obj_ptr };
+    if !obj.is_shared_array_buffer_obj() {
+        return Err(crate::error::create_type_error(
+            vm,
+            "SharedArrayBuffer method called on incompatible receiver",
+        ));
+    }
+    let Some(payload_ptr) = obj.native_fn() else {
+        return Err(crate::error::create_type_error(vm, "SharedArrayBuffer internal state invalid"));
+    };
+    let payload_ptr = payload_ptr.as_ptr() as *mut ArrayBufferPayload;
+    if payload_ptr.is_null() {
+        return Err(crate::error::create_type_error(vm, "SharedArrayBuffer internal state invalid"));
+    }
+    Ok(payload_ptr)
+}
+
+/// `SharedArrayBuffer.prototype.byteLength` getter：返回缓冲区字节数
+/// （定长臂读载荷 len；growable 臂归后续面）。
+pub fn shared_array_buffer_byte_length<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
+    let this_val = vm.reg(if args.is_empty() { 0 } else { args[0] });
+    let payload_ptr = native_try!(shared_array_buffer_payload(vm, this_val));
+    // SAFETY: payload_ptr 经 shared_array_buffer_payload 校验为合法 SAB 载荷。
+    let len = unsafe { &*payload_ptr }.data.as_ref().map_or(0, |d| d.len());
+    NativeResult::Ok(JsValue::int(len as i32))
+}
+
+/// `SharedArrayBuffer.prototype.growable` getter：定长臂恒 false
+/// （载荷存储态上限 0；growable 真值臂归后续面）。
+/// 非 SAB receiver 经品牌校验抛 TypeError（RequireInternalSlot 同语义）。
+pub fn shared_array_buffer_growable<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
+    let this_val = vm.reg(if args.is_empty() { 0 } else { args[0] });
+    native_try!(shared_array_buffer_payload(vm, this_val));
+    NativeResult::Ok(JsValue::bool(false))
+}
+
+/// `SharedArrayBuffer.prototype.maxByteLength` getter：非 growable
+/// （载荷存储态上限 0）返回当前字节数；growable 臂归后续面。
+pub fn shared_array_buffer_max_byte_length<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
+    let this_val = vm.reg(if args.is_empty() { 0 } else { args[0] });
+    let payload_ptr = native_try!(shared_array_buffer_payload(vm, this_val));
+    // SAFETY: payload_ptr 经 shared_array_buffer_payload 校验为合法 SAB 载荷。
+    let payload = unsafe { &*payload_ptr };
+    NativeResult::Ok(JsValue::int(payload.data.as_ref().map_or(0, |d| d.len()) as i32))
+}
+
 /// 读入口：校验 receiver 为 ArrayBuffer 并取载荷指针。detach（载荷 `data` 为
 /// `None`）不在此分叉，由消费方现读 `data` 时按既有错误形态处理。
 pub(crate) fn array_buffer_payload<H: VmHost>(

crates/oxide_builtins/src/lib.rs

@@ -6,7 +6,7 @@
 //! 每个内置方法以 `fn xxx<H: VmHost>(vm, args: &[u8]) -> NativeResult` 形式暴露，
 //! 由上层（oxide_vm / oxide_api）注册为 JS 全局对象上的 native function。
 //! 架构性延后的特性（Proxy、WeakMap、WeakSet、WeakRef、FinalizationRegistry、
-//! SharedArrayBuffer、Atomics）在 `stubs` 中仅提供占位实现，调用时抛 TypeError。
+//! Atomics）在 `stubs` 中仅提供占位实现，调用时抛 TypeError。
 
 /// Array 内置对象实现（目录模块：common 共享助手、from 构造器与静态方法、element 元素变更、iterate 高阶迭代、sort_iterator 排序与迭代协议、immutable ES2023 不可变方法族）。
 pub mod array;

crates/oxide_vm/src/bindings/bind_shared_array_buffer.rs

@@ -0,0 +1,57 @@
+use std::sync::Arc;
+
+use crate::bind_constructor;
+use crate::bindings::{bind_accessor_getter, configure_native_constructor};
+use oxide_kernel::kernel::{KernelCore, KernelSession};
+use oxide_types::object::JsObject;
+
+/// 把 SharedArrayBuffer 构造器与原型访问器绑定到 global。
+pub fn bind_shared_array_buffer(core: &Arc<KernelCore>, session: &KernelSession, global: &mut JsObject) {
+    let ctor_ptr = session.builtin_world().shared_array_buffer_constructor.as_ptr() as *mut JsObject;
+    let ctor = unsafe { &mut *ctor_ptr };
+    let proto_ptr = session.builtin_world().shared_array_buffer_proto.as_ptr() as *mut JsObject;
+    let proto = unsafe { &mut *proto_ptr };
+
+    configure_native_constructor(
+        ctor,
+        oxide_builtins::array_buffer::shared_array_buffer_constructor::<crate::vm::Vm> as *const (),
+        1,
+    );
+
+    // SAB 原型当前无静态方法（grow/growable 臂与 slice 归后续面）；
+    // byteLength/maxByteLength 两枚访问器（set 恒 undefined）读载荷字节数。
+    bind_accessor_getter(
+        core,
+        session,
+        proto,
+        "byteLength",
+        oxide_builtins::array_buffer::shared_array_buffer_byte_length::<crate::vm::Vm> as *const (),
+    );
+
+    bind_accessor_getter(
+        core,
+        session,
+        proto,
+        "maxByteLength",
+        oxide_builtins::array_buffer::shared_array_buffer_max_byte_length::<crate::vm::Vm> as *const (),
+    );
+
+    // growable 定长臂：恒 false，品牌校验抛 TypeError（proto 自身访问即抛）。
+    bind_accessor_getter(
+        core,
+        session,
+        proto,
+        "growable",
+        oxide_builtins::array_buffer::shared_array_buffer_growable::<crate::vm::Vm> as *const (),
+    );
+
+    bind_constructor!(
+        core,
+        global,
+        "SharedArrayBuffer",
+        ctor_ptr,
+        oxide_builtins::array_buffer::shared_array_buffer_constructor::<crate::vm::Vm>,
+        1,
+        hash: true
+    );
+}

crates/oxide_vm/src/bindings/bind_stubs.rs

@@ -8,7 +8,7 @@ use oxide_types::value::JsValue;
 
 use crate::bindings::{bind_global_value, configure_native_constructor};
 
-const STUBS: [(&str, *const (), u8); 7] = [
+const STUBS: [(&str, *const (), u8); 6] = [
     ("Proxy", oxide_builtins::stubs::proxy_stub::<crate::vm::Vm> as *const (), 2),
     ("WeakMap", oxide_builtins::stubs::weakmap_stub::<crate::vm::Vm> as *const (), 0),
     ("WeakSet", oxide_builtins::stubs::weakset_stub::<crate::vm::Vm> as *const (), 0),
@@ -18,15 +18,10 @@ const STUBS: [(&str, *const (), u8); 7] = [
         oxide_builtins::stubs::finalization_registry_stub::<crate::vm::Vm> as *const (),
         1,
     ),
-    (
-        "SharedArrayBuffer",
-        oxide_builtins::array_buffer::shared_array_buffer_constructor::<crate::vm::Vm> as *const (),
-        1,
-    ),
     ("Atomics", oxide_builtins::stubs::atomics_stub::<crate::vm::Vm> as *const (), 0),
 ];
 
-/// 把未实现内置（Proxy/WeakMap/WeakSet/WeakRef/FinalizationRegistry/SharedArrayBuffer/Atomics）
+/// 把未实现内置（Proxy/WeakMap/WeakSet/WeakRef/FinalizationRegistry/Atomics）
 /// 的 stub 构造器绑定到 global，并登记到 `stub_objects` 供快照跟踪。
 pub fn bind_stubs(core: &Arc<KernelCore>, session: &mut KernelSession, global: &mut JsObject) {
     let builtin_world = Arc::get_mut(&mut session.builtin_world)

crates/oxide_vm/src/bindings/mod.rs

@@ -44,6 +44,8 @@ pub mod bind_reflect;
 pub mod bind_regexp;
 /// Set 构造器与原型的 native 方法绑定。
 pub mod bind_set;
+/// SharedArrayBuffer 构造器与原型的 native 方法绑定。
+pub mod bind_shared_array_buffer;
 /// String 构造器与原型的 native 方法绑定。
 pub mod bind_string;
 /// 未实现内置（Proxy/BigInt/WeakMap 等）的 stub 构造器绑定。
@@ -632,9 +634,10 @@ fn install_to_string_tags(core: &Arc<KernelCore>, session: &KernelSession) {
     let sh = core.shape_forge().as_ref();
     let tag_id = oxide_types::private_key::WELL_KNOWN_SYMBOL_TO_STRING_TAG;
     let tag_key = oxide_types::private_key::make_well_known_symbol_key(tag_id);
-    let cases: [(*mut JsObject, &str); 12] = [
+    let cases: [(*mut JsObject, &str); 13] = [
         (world.map_proto.as_ptr() as *mut JsObject, "Map"),
         (world.array_buffer_proto.as_ptr() as *mut JsObject, "ArrayBuffer"),
+        (world.shared_array_buffer_proto.as_ptr() as *mut JsObject, "SharedArrayBuffer"),
         (world.set_proto.as_ptr() as *mut JsObject, "Set"),
         (world.data_view_proto.as_ptr() as *mut JsObject, "DataView"),
         (world.array_iterator_proto.as_ptr() as *mut JsObject, "Array Iterator"),
@@ -884,11 +887,6 @@ fn bind_stub_globals(core: &Arc<KernelCore>, session: &KernelSession, global: &m
             oxide_builtins::stubs::finalization_registry_stub::<crate::vm::Vm> as *const (),
             1,
         ),
-        (
-            "SharedArrayBuffer",
-            oxide_builtins::array_buffer::shared_array_buffer_constructor::<crate::vm::Vm> as *const (),
-            1,
-        ),
         ("Atomics", oxide_builtins::stubs::atomics_stub::<crate::vm::Vm> as *const (), 0),
     ]
     .into_iter()
@@ -923,6 +921,11 @@ pub fn bind_global_builtin_slots(core: &Arc<KernelCore>, session: &KernelSession
         oxide_builtins::array_buffer::array_buffer_constructor::<crate::vm::Vm> as *const (),
         1,
     );
+    configure_existing_ctor(
+        &world.shared_array_buffer_constructor,
+        oxide_builtins::array_buffer::shared_array_buffer_constructor::<crate::vm::Vm> as *const (),
+        1,
+    );
     configure_existing_ctor(
         &world.data_view_constructor,
         oxide_builtins::data_view::data_view_constructor::<crate::vm::Vm> as *const (),
@@ -976,6 +979,10 @@ pub fn bind_global_builtin_slots(core: &Arc<KernelCore>, session: &KernelSession
             "ArrayBuffer",
             JsValue::from_js_object(world.array_buffer_constructor.as_ptr() as *mut JsObject),
         ),
+        (
+            "SharedArrayBuffer",
+            JsValue::from_js_object(world.shared_array_buffer_constructor.as_ptr() as *mut JsObject),
+        ),
         ("DataView", JsValue::from_js_object(world.data_view_constructor.as_ptr() as *mut JsObject)),
         ("Error", JsValue::from_js_object(world.error_constructor.as_ptr() as *mut JsObject)),
         ("String", JsValue::from_js_object(world.string_constructor.as_ptr() as *mut JsObject)),
@@ -1160,6 +1167,9 @@ pub fn rebind_dirty_builtins(core: &Arc<KernelCore>, session: &mut KernelSession
     if dirty.map_or(true, |d| d.array_buffer) {
         bind_array_buffer::bind_array_buffer(core, session, global);
     }
+    if dirty.map_or(true, |d| d.shared_array_buffer) {
+        bind_shared_array_buffer::bind_shared_array_buffer(core, session, global);
+    }
     if dirty.map_or(true, |d| d.data_view) {
         bind_data_view::bind_data_view(core, session, global);
     }

crates/oxide_vm/tests/builtins_arraybuffer_state_tests.rs

@@ -1158,3 +1158,167 @@ fn sab_constructor_and_brand_rejection() {
     .unwrap();
     assert!(result.as_bool());
 }
+
+/// 构造器 meta 面钉：length 值 1 描述符 {f,f,t}，prototype {f,f,f} 值恒等，
+/// prototype.constructor 互指 {1,0,1}，proto 链挂 Object.prototype。
+#[test]
+fn sab_ctor_meta_descriptors() {
+    let mut vm = Vm::new();
+    let result = eval(
+        &mut vm,
+        "(function () { \
+         var l = Object.getOwnPropertyDescriptor(SharedArrayBuffer, 'length'); \
+         var p = Object.getOwnPropertyDescriptor(SharedArrayBuffer, 'prototype'); \
+         var c = Object.getOwnPropertyDescriptor(SharedArrayBuffer.prototype, 'constructor'); \
+         return l.value === 1 && l.writable === false && l.enumerable === false && l.configurable === true \
+            && p.value === SharedArrayBuffer.prototype \
+            && p.writable === false && p.enumerable === false && p.configurable === false \
+            && SharedArrayBuffer.prototype.constructor === SharedArrayBuffer \
+            && c.writable === true && c.enumerable === false && c.configurable === true \
+            && Object.getPrototypeOf(SharedArrayBuffer.prototype) === Object.prototype; })()",
+    )
+    .unwrap();
+    assert!(result.as_bool());
+}
+
+/// 原型 @@toStringTag 钉：值 "SharedArrayBuffer"、{f,f,t}，Object.prototype
+/// toString 经标签链读出 "[object SharedArrayBuffer]"。
+#[test]
+fn sab_proto_to_string_tag() {
+    let mut vm = Vm::new();
+    let result = eval(
+        &mut vm,
+        "(function () { \
+         var d = Object.getOwnPropertyDescriptor(SharedArrayBuffer.prototype, Symbol.toStringTag); \
+         return d.value === 'SharedArrayBuffer' \
+            && d.writable === false && d.enumerable === false && d.configurable === true \
+            && Object.prototype.toString.call(new SharedArrayBuffer(0)) === '[object SharedArrayBuffer]'; })()",
+    )
+    .unwrap();
+    assert!(result.as_bool());
+}
+
+/// 实例 proto 挂回钉：getPrototypeOf === proto，无 own byteLength 数据属性，
+/// 构造长度经原型访问器读回，访问器描述符 {get,set 缺,e:false,c:true}。
+#[test]
+fn sab_instance_proto_and_readback() {
+    let mut vm = Vm::new();
+    let result = eval(
+        &mut vm,
+        "(function () { \
+         var sab = new SharedArrayBuffer(42); \
+         var own = Object.getOwnPropertyDescriptor(sab, 'byteLength'); \
+         var d = Object.getOwnPropertyDescriptor(SharedArrayBuffer.prototype, 'byteLength'); \
+         return Object.getPrototypeOf(sab) === SharedArrayBuffer.prototype \
+            && SharedArrayBuffer.prototype.constructor === SharedArrayBuffer \
+            && own === undefined \
+            && sab.byteLength === 42 \
+            && typeof d.get === 'function' && d.set === undefined \
+            && d.enumerable === false && d.configurable === true; })()",
+    )
+    .unwrap();
+    assert!(result.as_bool());
+}
+
+/// receiver 品牌校验钉：get.call(undefined/{} / ArrayBuffer 实例) 均 TypeError。
+#[test]
+fn sab_bytelength_this_checks() {
+    let mut vm = Vm::new();
+    let result = eval(
+        &mut vm,
+        "(function () { \
+         var d = Object.getOwnPropertyDescriptor(SharedArrayBuffer.prototype, 'byteLength'); \
+         var undef_threw = false, obj_threw = false, ab_threw = false; \
+         try { d.get.call(undefined); } catch (e) { undef_threw = e instanceof TypeError; } \
+         try { d.get.call({}); } catch (e) { obj_threw = e instanceof TypeError; } \
+         try { d.get.call(new ArrayBuffer(4)); } catch (e) { ab_threw = e instanceof TypeError; } \
+         return undef_threw && obj_threw && ab_threw; })()",
+    )
+    .unwrap();
+    assert!(result.as_bool());
+}
+
+/// maxByteLength 非 growable 臂钉：值同字节数，描述符 {get,set 缺,e:false,c:true}，
+/// getter name/length 元数据。
+#[test]
+fn sab_max_bytelength_descriptor_and_values() {
+    let mut vm = Vm::new();
+    let result = eval(
+        &mut vm,
+        "(function () { \
+         var sab8 = new SharedArrayBuffer(8); \
+         var sab0 = new SharedArrayBuffer(0); \
+         var d = Object.getOwnPropertyDescriptor(SharedArrayBuffer.prototype, 'maxByteLength'); \
+         return sab8.maxByteLength === 8 && sab0.maxByteLength === 0 \
+            && typeof d.get === 'function' && d.set === undefined \
+            && d.enumerable === false && d.configurable === true \
+            && d.get.name === 'get maxByteLength' && d.get.length === 0; })()",
+    )
+    .unwrap();
+    assert!(result.as_bool());
+}
+
+/// GetPrototypeFromConstructor 钉：newTarget.prototype 为对象时实例挂其原型；
+/// prototype 属性非对象时回落 %SharedArrayBuffer.prototype%；getter 抛错原值传播。
+#[test]
+fn sab_new_target_proto_and_fallback() {
+    let mut vm = Vm::new();
+    let result = eval(
+        &mut vm,
+        "(function () { \
+         var c = Reflect.construct(SharedArrayBuffer, [8], Object); \
+         if (Object.getPrototypeOf(c) !== Object.prototype) { return false; } \
+         var D = function () {}; \
+         D.prototype = null; \
+         var d = Reflect.construct(SharedArrayBuffer, [4], D); \
+         if (Object.getPrototypeOf(d) !== SharedArrayBuffer.prototype) { return false; } \
+         var E = function () {}; \
+         Object.defineProperty(E, 'prototype', { get: function () { throw new RangeError('x'); } }); \
+         var threw = false; \
+         try { Reflect.construct(SharedArrayBuffer, [1], E); } catch (e) { threw = e instanceof RangeError; } \
+         return threw; })()",
+    )
+    .unwrap();
+    assert!(result.as_bool());
+}
+
+/// full_reset（dirty 重建）重绑钉：重建后构造、实例读回、proto 互指、
+/// toStringTag 标签全部存活。
+#[test]
+fn sab_full_reset_rebinds() {
+    let mut vm = Vm::new();
+    eval(&mut vm, "new SharedArrayBuffer(4).byteLength; 0").expect("run1");
+    vm.full_reset();
+    let result = eval(
+        &mut vm,
+        "(function () { \
+         var sab = new SharedArrayBuffer(4); \
+         return (sab instanceof SharedArrayBuffer) + '|' \
+            + (sab.byteLength === 4) + '|' \
+            + (SharedArrayBuffer.prototype.constructor === SharedArrayBuffer) + '|' \
+            + (sab[Symbol.toStringTag] === 'SharedArrayBuffer'); })()",
+    )
+    .unwrap();
+    let text = vm.lookup_str(result).unwrap_or_default().to_string();
+    assert_eq!(text, "true|true|true|true");
+}
+
+/// STUBS 表收缩钉：剩余 6 枚 stub 全局仍为 function 且 Atomics 调用仍抛
+/// TypeError（占位行为未随 SAB 移出而漂移）。
+#[test]
+fn sab_stubs_shrunk_six_remain() {
+    let mut vm = Vm::new();
+    let result = eval(
+        &mut vm,
+        "(function () { \
+         var names = ['Proxy', 'WeakMap', 'WeakSet', 'WeakRef', 'FinalizationRegistry', 'Atomics']; \
+         for (var i = 0; i < names.length; i++) { \
+            if (typeof globalThis[names[i]] !== 'function') { return false; } \
+         } \
+         var threw = false; \
+         try { Atomics.add(new SharedArrayBuffer(4), 0, 1); } catch (e) { threw = e instanceof TypeError; } \
+         return threw; })()",
+    )
+    .unwrap();
+    assert!(result.as_bool());
+}