feat: ArrayBuffer 三访问器与 markImmutable 及 detach 宿主真化

crates/oxide_builtins/src/array_buffer.rs

@@ -107,7 +107,7 @@ pub(crate) fn new_array_buffer<H: VmHost>(
     vm.alloc_object(obj)
 }
 
-fn array_buffer_payload_ptr(obj: &JsObject) -> Option<*mut ArrayBufferPayload> {
+pub(crate) fn array_buffer_payload_ptr(obj: &JsObject) -> Option<*mut ArrayBufferPayload> {
     if !obj.is_array_buffer_obj() {
         return None;
     }
@@ -276,15 +276,14 @@ pub fn array_buffer_constructor<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeRes
     NativeResult::Ok(JsValue::from_js_object(obj_ptr))
 }
 
-/// `ArrayBuffer.prototype.byteLength` getter：返回缓冲区字节数。
+/// `ArrayBuffer.prototype.byteLength` getter：返回缓冲区字节数；
+/// detached 缓冲返回 0。
 pub fn 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!(array_buffer_payload(vm, this_val));
     // SAFETY: payload_ptr 经 array_buffer_payload 校验为合法 ArrayBuffer 载荷。
-    let Some(data) = unsafe { &*payload_ptr }.data.as_ref() else {
-        return NativeResult::Err(crate::error::create_type_error(vm, "ArrayBuffer internal state invalid"));
-    };
-    NativeResult::Ok(JsValue::int(data.len() as i32))
+    let len = unsafe { &*payload_ptr }.data.as_ref().map_or(0, |d| d.len());
+    NativeResult::Ok(JsValue::int(len as i32))
 }
 
 /// `ArrayBuffer.prototype.resizable` getter：返回缓冲区是否可 resize
@@ -297,6 +296,73 @@ pub fn array_buffer_resizable<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResul
     NativeResult::Ok(JsValue::bool(resizable))
 }
 
+/// `ArrayBuffer.prototype.maxByteLength` getter：detached → +0；定长 →
+/// 当前字节数；resizable → 真实上限（存储态 − 1 解码）。
+pub fn 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!(array_buffer_payload(vm, this_val));
+    // SAFETY: payload_ptr 经 array_buffer_payload 校验为合法 ArrayBuffer 载荷。
+    let payload = unsafe { &*payload_ptr };
+    if payload.data.is_none() {
+        return NativeResult::Ok(JsValue::int(0));
+    }
+    let value = if payload.max_byte_length == 0 {
+        payload.data.as_ref().map_or(0, |d| d.len())
+    } else {
+        payload.max_byte_length - 1
+    };
+    NativeResult::Ok(JsValue::int(value as i32))
+}
+
+/// `ArrayBuffer.prototype.immutable` getter：返回载荷 immutable 标志。
+pub fn array_buffer_immutable<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!(array_buffer_payload(vm, this_val));
+    // SAFETY: payload_ptr 经 array_buffer_payload 校验为合法 ArrayBuffer 载荷。
+    NativeResult::Ok(JsValue::bool(unsafe { &*payload_ptr }.immutable))
+}
+
+/// `ArrayBuffer.prototype.detached` getter：detached 判据即载荷 `data` 为
+/// `None`。
+pub fn array_buffer_detached<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!(array_buffer_payload(vm, this_val));
+    // SAFETY: payload_ptr 经 array_buffer_payload 校验为合法 ArrayBuffer 载荷。
+    NativeResult::Ok(JsValue::bool(unsafe { &*payload_ptr }.data.is_none()))
+}
+
+/// `ArrayBuffer.prototype.markImmutable()`：定长附着缓冲区置 immutable 标志
+/// 并返回接收者；已置位再调为幂等 no-op。
+///
+/// # 步骤
+/// 1. this 品牌校验（非对象/非 ArrayBuffer → TypeError）。
+/// 2. detached → TypeError。
+/// 3. resizable（存储态上限非 0）→ TypeError。
+/// 4. 置 immutable 标志并返回 O。
+pub fn array_buffer_mark_immutable<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!(array_buffer_payload(vm, this_val));
+    // SAFETY: payload_ptr 经 array_buffer_payload 校验为合法 ArrayBuffer 载荷。
+    let payload = unsafe { &mut *payload_ptr };
+    if payload.data.is_none() {
+        return NativeResult::Err(crate::error::create_type_error(vm, "ArrayBuffer internal state invalid"));
+    }
+    if payload.max_byte_length != 0 {
+        return NativeResult::Err(crate::error::create_type_error(vm, "ArrayBuffer is not resizable"));
+    }
+    payload.immutable = true;
+    NativeResult::Ok(this_val)
+}
+
+/// ArrayBuffer detach 生产路径：品牌守卫后载荷 `data → None`（字节缓冲随
+/// `Option` 置空释放，载荷盒本体存活至对象 drop）。返回 undefined。
+pub fn detach_array_buffer_native<H: VmHost>(vm: &mut H, this_val: JsValue) -> NativeResult {
+    let payload_ptr = native_try!(array_buffer_payload(vm, this_val));
+    // SAFETY: payload_ptr 经 array_buffer_payload 校验为合法 ArrayBuffer 载荷。
+    unsafe { (*payload_ptr).data = None };
+    NativeResult::Ok(JsValue::undefined())
+}
+
 /// `ArrayBuffer.prototype.resize(newLength)`：可 resize 缓冲区原地调整长度，
 /// 前缀保留、增补零填充、缩小截断。
 ///
@@ -304,15 +370,16 @@ pub fn array_buffer_resizable<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResul
 /// 1. this 品牌校验（非对象/非 ArrayBuffer → TypeError）。
 /// 2. 载荷三状态位（detached / immutable / max）先于任何 JS 调用拷入局部
 ///    标量。
-/// 3. detached → TypeError（detach 路径由 transfer 族激活）。
+/// 3. detached → TypeError。
 /// 4. immutable → TypeError。
 /// 5. newByteLength = ToIntegerOrInfinity(newLength) 传播式（NaN → 0，
 ///    ±Infinity 保留）。
 /// 6. 定长（存储态上限 = 0）→ TypeError，先于界判。
 /// 7. newByteLength < 0 或 > 真实上限（存储态 − 1）→ RangeError。
 /// 8. 重取载荷指针：步 5 的 JS 调用可触发 epoch 晋升，旧指针悬垂。
-/// 9. `Vec::resize` 一次调用收口目标长度。
-/// 10. 返回 undefined。
+/// 9. 载荷重检：强转调用可已 detach 本缓冲，detached 与步 3 同文本 TypeError。
+/// 10. `Vec::resize` 一次调用收口目标长度。
+/// 11. 返回 undefined。
 pub fn array_buffer_resize<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
     let this_reg = if args.is_empty() { 0 } else { args[0] };
     let this_val = vm.reg(this_reg);
@@ -343,10 +410,12 @@ pub fn array_buffer_resize<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
     // 重写，须重新读取后再取载荷指针（旧 this 值可能指向已释放 epoch 对象）。
     let this_val = vm.reg(this_reg);
     let payload_ptr = native_try!(array_buffer_payload(vm, this_val));
-    // SAFETY: 重取的 payload_ptr 指向存活载荷盒；detached 已在步 3 排除，
-    // data 必为 Some。
-    let payload = unsafe { &mut *payload_ptr };
-    payload.data.as_mut().expect("detached 已排除").resize(new_length as usize, 0);
+    // SAFETY: 重取的 payload_ptr 指向存活载荷盒。
+    let Some(data) = (unsafe { &mut *payload_ptr }).data.as_mut() else {
+        // 步 5 的强转调用可在中途 detach 本缓冲：重检不通过按步 3 同文本抛。
+        return NativeResult::Err(crate::error::create_type_error(vm, "ArrayBuffer internal state invalid"));
+    };
+    data.resize(new_length as usize, 0);
     NativeResult::Ok(JsValue::undefined())
 }
 
@@ -401,6 +470,7 @@ pub fn array_buffer_to_string<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResul
 #[cfg(test)]
 mod tests {
     use super::*;
+    use oxide_vm::vm::Vm;
 
     /// 手工构造带载荷盒的 ArrayBuffer 对象（不经 Vm，只验 GC 三自由函数）。
     fn ab_object_with_payload(payload: ArrayBufferPayload) -> JsObject {
@@ -495,4 +565,56 @@ mod tests {
         // SAFETY: 测试构造的盒，恰好释放一次。
         unsafe { drop(Box::from_raw(payload_ptr)) };
     }
+
+    /// JS 求值辅助：单脚本编译执行，返回完成值。
+    fn eval_ab(vm: &mut Vm, source: &str) -> Result<JsValue, String> {
+        let allocator = oxide_parser::Allocator::default();
+        let program = oxide_parser::parse(&allocator, source).map_err(|e| format!("parse: {:?}", e[0].message))?;
+        let module = oxide_compiler::compiler::Compiler::new()
+            .compile(&program)
+            .map_err(|e| format!("compile: {e}"))?;
+        vm.run(&std::sync::Arc::new(module))
+    }
+
+    /// markImmutable 标志面钉：置位返回 O、二调幂等、resizable/detached 两
+    /// TypeError 形。
+    #[test]
+    fn mark_immutable_flag_and_guard() {
+        let mut vm = Vm::new();
+        let r = eval_ab(
+            &mut vm,
+            "var ab = new ArrayBuffer(4); \
+             var ret = ab.markImmutable(); \
+             ret === ab && ab.immutable === true && ab.markImmutable() === ab \
+             && ab.immutable === true && ab.byteLength === 4",
+        )
+        .unwrap();
+        assert!(r.as_bool());
+        let e = eval_ab(&mut vm, "new ArrayBuffer(4, {maxByteLength: 8}).markImmutable()").unwrap_err();
+        assert!(e.contains("TypeError"), "resizable 应抛 TypeError: {e}");
+        let e = eval_ab(
+            &mut vm,
+            "var ab = new ArrayBuffer(4); $262.detachArrayBuffer(ab); \
+             try { ab.markImmutable(); 'no-throw' } catch (err) { err.name }",
+        )
+        .unwrap();
+        assert_eq!(vm.lookup_str(e).unwrap(), "TypeError");
+    }
+
+    /// resize 后置 detach 重检钉：强转调用中途 detach 后按 TypeError 抛，
+    /// 不触碰已 detach 载荷（现树 expect 臂的 abort 钉改点）。
+    #[test]
+    fn resize_recheck_after_coercion_detach() {
+        let mut vm = Vm::new();
+        let e = eval_ab(
+            &mut vm,
+            "var ab = new ArrayBuffer(64, {maxByteLength: 1024}); \
+             try { ab.resize({ valueOf() { $262.detachArrayBuffer(ab); return 0; } }); \
+                   'no-throw' } catch (err) { err.name }",
+        )
+        .unwrap();
+        assert_eq!(vm.lookup_str(e).unwrap(), "TypeError");
+        let r = eval_ab(&mut vm, "ab.detached === true && ab.byteLength === 0").unwrap();
+        assert!(r.as_bool());
+    }
 }

crates/oxide_builtins/src/typed_array.rs

@@ -6,7 +6,8 @@ use oxide_types::private_key::{int_key_value, is_int_key, make_well_known_symbol
 use oxide_types::value::JsValue;
 
 use crate::array_buffer::{
-    array_buffer_payload, default_array_buffer_proto, new_array_buffer, MAX_ARRAY_BUFFER_LENGTH,
+    array_buffer_payload, array_buffer_payload_ptr, default_array_buffer_proto, new_array_buffer,
+    MAX_ARRAY_BUFFER_LENGTH,
 };
 
 use oxide_runtime_api::{NativeResult, VmHost};
@@ -336,7 +337,8 @@ pub fn ta_index_gate<H: VmHost>(vm: &H, obj: &JsObject, key_si: u32) -> TaIndexG
 }
 
 /// 取 TypedArray 视图长度（供只需 length 不需门的枚举面消费方）；
-/// 非 TypedArray 或内部状态无效返回 0。
+/// 非 TypedArray 或内部状态无效返回 0。底层缓冲已 detach（载荷 `data`
+/// 为 `None`）时视图长度统一为 0，界内键经门归数字无效。
 pub(crate) fn ta_view_length<H: VmHost>(_vm: &H, obj: &JsObject) -> usize {
     let Some(ptr) = typed_array_data_ptr(obj) else {
         return 0;
@@ -347,6 +349,16 @@ pub(crate) fn ta_view_length<H: VmHost>(_vm: &H, obj: &JsObject) -> usize {
     // SAFETY: ptr 非空，为 TypedArray 对象 native_fn 槽内的 Box<TypedArrayData>，
     // 与对象同生命周期，此处只读拷贝视图字段。
     let view = unsafe { *ptr };
+    // 底层缓冲已 detach：视图长度统一 0。
+    let buffer_ptr = view.buffer.as_js_object_ptr();
+    if !buffer_ptr.is_null() {
+        // SAFETY: buffer 对象与视图同生命周期，此处只读载荷存活位。
+        if let Some(payload_ptr) = array_buffer_payload_ptr(unsafe { &*buffer_ptr }) {
+            if !payload_ptr.is_null() && unsafe { (*payload_ptr).data.is_none() } {
+                return 0;
+            }
+        }
+    }
     view.length
 }
 

crates/oxide_test262/src/harness.rs

@@ -70,8 +70,6 @@ fn is_blacklisted_harness(name: &str) -> bool {
             | "atomicsHelper.js"
             | "proxyTrapsHelper.js"
             | "tcoHelper.js"
-            | "detachArrayBuffer.js"
-            | "resizableArrayBufferUtils.js"
             | "byteConversionValues.js"
             | "compareIterator.js"
             | "iteratorZipUtils.js"

crates/oxide_vm/src/bindings/bind_array_buffer.rs

@@ -58,6 +58,11 @@ pub fn bind_array_buffer(core: &Arc<KernelCore>, session: &KernelSession, global
                 oxide_builtins::array_buffer::array_buffer_to_string::<crate::vm::Vm> as *const (),
                 0,
             ),
+            (
+                "markImmutable",
+                oxide_builtins::array_buffer::array_buffer_mark_immutable::<crate::vm::Vm> as *const (),
+                0,
+            ),
         ],
     );
 
@@ -79,6 +84,34 @@ pub fn bind_array_buffer(core: &Arc<KernelCore>, session: &KernelSession, global
         oxide_builtins::array_buffer::array_buffer_resizable::<crate::vm::Vm> as *const (),
     );
 
+    // maxByteLength 原型访问器（set 恒 undefined）：detached 回 +0，定长回
+    // 当前字节数，resizable 回存储态上限 − 1。
+    bind_accessor_getter(
+        core,
+        session,
+        proto,
+        "maxByteLength",
+        oxide_builtins::array_buffer::array_buffer_max_byte_length::<crate::vm::Vm> as *const (),
+    );
+
+    // immutable 原型访问器（set 恒 undefined）：读载荷 immutable 标志。
+    bind_accessor_getter(
+        core,
+        session,
+        proto,
+        "immutable",
+        oxide_builtins::array_buffer::array_buffer_immutable::<crate::vm::Vm> as *const (),
+    );
+
+    // detached 原型访问器（set 恒 undefined）：读载荷 data 存活位。
+    bind_accessor_getter(
+        core,
+        session,
+        proto,
+        "detached",
+        oxide_builtins::array_buffer::array_buffer_detached::<crate::vm::Vm> as *const (),
+    );
+
     bind_constructor!(
         core,
         global,

crates/oxide_vm/src/test262_host.rs

@@ -57,9 +57,11 @@ pub fn eval_script(vm: &mut Vm, args: &[u8]) -> NativeResult {
     }
 }
 
-/// `$262.detachArrayBuffer(buf)`：ArrayBuffer detach 未实现，抛能力缺失错误。
-pub fn detach_array_buffer(vm: &mut Vm, _args: &[u8]) -> NativeResult {
-    not_supported(vm, "detachArrayBuffer")
+/// `$262.detachArrayBuffer(buf)`：真 detach——品牌守卫后载荷 `data → None`，
+/// 返回 undefined。
+pub fn detach_array_buffer(vm: &mut Vm, args: &[u8]) -> NativeResult {
+    let this_val = if args.len() > 1 { vm.reg(args[1]) } else { JsValue::undefined() };
+    oxide_builtins::array_buffer::detach_array_buffer_native::<Vm>(vm, this_val)
 }
 
 /// `$262.createRealm()`：跨 realm 未支持，抛能力缺失错误。

crates/oxide_vm/tests/builtins_arraybuffer_state_tests.rs

@@ -475,3 +475,199 @@ fn ab_length_range_error_not_regressed() {
     .unwrap();
     assert!(result.as_bool());
 }
+
+/// maxByteLength 访问器钉：描述符 {get 函数, set undefined, e:0, c:1}、
+/// name/length、定长 42→42 / 0→0、resizable(4,{max 8})→8、detached→0、
+/// this 四形 TypeError。
+#[test]
+fn ab_maxbytelength_accessor_pins() {
+    let mut vm = Vm::new();
+    let result = eval(
+        &mut vm,
+        "var d = Object.getOwnPropertyDescriptor(ArrayBuffer.prototype, 'maxByteLength'); \
+         var ok = d.set === undefined && typeof d.get === 'function' \
+           && d.enumerable === false && d.configurable === true \
+           && d.get.name === 'get maxByteLength' && d.get.length === 0; \
+         var t1 = false, t2 = false, t3 = false, t4 = false; \
+         try { d.get.call(ArrayBuffer.prototype); } catch (e) { t1 = e instanceof TypeError; } \
+         try { d.get.call(undefined); } catch (e) { t2 = e instanceof TypeError; } \
+         try { d.get.call({}); } catch (e) { t3 = e instanceof TypeError; } \
+         try { d.get.call([]); } catch (e) { t4 = e instanceof TypeError; } \
+         ok && t1 && t2 && t3 && t4 \
+           && new ArrayBuffer(42).maxByteLength === 42 \
+           && new ArrayBuffer(0).maxByteLength === 0 \
+           && new ArrayBuffer(4, {maxByteLength: 8}).maxByteLength === 8",
+    )
+    .unwrap();
+    assert!(result.as_bool());
+    let result =
+        eval(&mut vm, "var ab = new ArrayBuffer(1); $262.detachArrayBuffer(ab); ab.maxByteLength === 0").unwrap();
+    assert!(result.as_bool());
+}
+
+/// immutable 访问器钉：描述符形、markImmutable 前后 false→true、this 两形。
+#[test]
+fn ab_immutable_accessor_pins() {
+    let mut vm = Vm::new();
+    let result = eval(
+        &mut vm,
+        "var d = Object.getOwnPropertyDescriptor(ArrayBuffer.prototype, 'immutable'); \
+         var ok = d.set === undefined && typeof d.get === 'function' \
+           && d.enumerable === false && d.configurable === true \
+           && d.get.name === 'get immutable' && d.get.length === 0; \
+         var ab = new ArrayBuffer(2); \
+         var before = ab.immutable; \
+         ab.markImmutable(); \
+         var t1 = false, t2 = false; \
+         try { d.get.call({}); } catch (e) { t1 = e instanceof TypeError; } \
+         try { d.get.call(undefined); } catch (e) { t2 = e instanceof TypeError; } \
+         ok && before === false && ab.immutable === true && t1 && t2",
+    )
+    .unwrap();
+    assert!(result.as_bool());
+}
+
+/// detached 访问器钉：描述符形、附着 false → $262 detach → true、this 两形。
+#[test]
+fn ab_detached_accessor_pins() {
+    let mut vm = Vm::new();
+    let result = eval(
+        &mut vm,
+        "var d = Object.getOwnPropertyDescriptor(ArrayBuffer.prototype, 'detached'); \
+         var ok = d.set === undefined && typeof d.get === 'function' \
+           && d.enumerable === false && d.configurable === true \
+           && d.get.name === 'get detached' && d.get.length === 0; \
+         var ab = new ArrayBuffer(1); \
+         var before = ab.detached; \
+         $262.detachArrayBuffer(ab); \
+         var t1 = false, t2 = false; \
+         try { d.get.call({}); } catch (e) { t1 = e instanceof TypeError; } \
+         try { d.get.call(undefined); } catch (e) { t2 = e instanceof TypeError; } \
+         ok && before === false && ab.detached === true && t1 && t2",
+    )
+    .unwrap();
+    assert!(result.as_bool());
+}
+
+/// byteLength detached 臂改点钉：detach 后读 0（原 TypeError 臂）。
+#[test]
+fn ab_bytelength_detached_zero() {
+    let mut vm = Vm::new();
+    let result = eval(&mut vm, "var ab = new ArrayBuffer(1); $262.detachArrayBuffer(ab); ab.byteLength === 0").unwrap();
+    assert!(result.as_bool());
+}
+
+/// resizable detached 不受影响钉：resizable(1,{max 1}) detach 后仍 true。
+#[test]
+fn ab_resizable_detached_unchanged() {
+    let mut vm = Vm::new();
+    let result = eval(
+        &mut vm,
+        "var ab = new ArrayBuffer(1, {maxByteLength: 1}); $262.detachArrayBuffer(ab); ab.resizable === true",
+    )
+    .unwrap();
+    assert!(result.as_bool());
+}
+
+/// own maxByteLength 数据属性与原型访问器并存读同值钉（resizable 专属）。
+#[test]
+fn ab_maxbytelength_own_still_resizable_only() {
+    let mut vm = Vm::new();
+    let result = eval(
+        &mut vm,
+        "var ab = new ArrayBuffer(4, {maxByteLength: 8}); \
+         Object.getOwnPropertyDescriptor(ab, 'maxByteLength').value === 8 && ab.maxByteLength === 8",
+    )
+    .unwrap();
+    assert!(result.as_bool());
+}
+
+/// markImmutable 返回接收者并置位钉：返回 === ab、immutable true、二调幂等、
+/// byteLength 不变。
+#[test]
+fn ab_markimmutable_returns_this_and_sets_flag() {
+    let mut vm = Vm::new();
+    let result = eval(
+        &mut vm,
+        "var ab = new ArrayBuffer(4); \
+         var ret = ab.markImmutable(); \
+         ret === ab && ab.immutable === true && ab.markImmutable() === ab \
+         && ab.immutable === true && ab.byteLength === 4",
+    )
+    .unwrap();
+    assert!(result.as_bool());
+}
+
+/// markImmutable resizable 源钉：TypeError。
+#[test]
+fn ab_markimmutable_resizable_type_error() {
+    let mut vm = Vm::new();
+    let result = eval(
+        &mut vm,
+        "var t = false; \
+         try { new ArrayBuffer(4, {maxByteLength: 8}).markImmutable(); } catch (e) { t = e instanceof TypeError; } \
+         t",
+    )
+    .unwrap();
+    assert!(result.as_bool());
+}
+
+/// markImmutable detached 源钉：$262 detach 后 TypeError。
+#[test]
+fn ab_markimmutable_detached_type_error() {
+    let mut vm = Vm::new();
+    let result = eval(
+        &mut vm,
+        "var ab = new ArrayBuffer(4); $262.detachArrayBuffer(ab); \
+         var t = false; \
+         try { ab.markImmutable(); } catch (e) { t = e instanceof TypeError; } \
+         t",
+    )
+    .unwrap();
+    assert!(result.as_bool());
+}
+
+/// markImmutable this 品牌校验钉：原型/undefined/{}/[] 四形 TypeError。
+#[test]
+fn ab_markimmutable_this_checks() {
+    let mut vm = Vm::new();
+    let result = eval(
+        &mut vm,
+        "var t1 = false, t2 = false, t3 = false, t4 = false; \
+         try { ArrayBuffer.prototype.markImmutable(); } catch (e) { t1 = e instanceof TypeError; } \
+         try { ArrayBuffer.prototype.markImmutable.call(undefined); } catch (e) { t2 = e instanceof TypeError; } \
+         try { ArrayBuffer.prototype.markImmutable.call({}); } catch (e) { t3 = e instanceof TypeError; } \
+         try { ArrayBuffer.prototype.markImmutable.call([]); } catch (e) { t4 = e instanceof TypeError; } \
+         t1 && t2 && t3 && t4",
+    )
+    .unwrap();
+    assert!(result.as_bool());
+}
+
+/// P2-1 门钉：TA 界内整数键 detached 前 NumericValid(0)、detached 后
+/// NumericInvalid（232.19.2 Get 臂 detached 界内键用例的前置钉）。
+#[test]
+fn ab_ta_view_length_detached_zero() {
+    let mut vm = Vm::new();
+    eval(
+        &mut vm,
+        "var ab = new ArrayBuffer(8); \
+         globalThis.__ab = ab; globalThis.__ta = new Uint8Array(ab); true",
+    )
+    .unwrap();
+    let si = vm.kernel_core().perm_interner().intern("0").0;
+    let ta_val = eval(&mut vm, "globalThis.__ta").unwrap();
+    // SAFETY: __ta 为已晋升 session 的 TypedArray 对象，借用止于断言、不跨下一次 eval。
+    let ta_obj = unsafe { &*ta_val.as_js_object_ptr() };
+    assert_eq!(
+        oxide_builtins::typed_array::ta_index_gate(&vm, ta_obj, si),
+        oxide_builtins::typed_array::TaIndexGate::NumericValid(0)
+    );
+    eval(&mut vm, "$262.detachArrayBuffer(globalThis.__ab); true").unwrap();
+    let ta_val = eval(&mut vm, "globalThis.__ta").unwrap();
+    let ta_obj = unsafe { &*ta_val.as_js_object_ptr() };
+    assert_eq!(
+        oxide_builtins::typed_array::ta_index_gate(&vm, ta_obj, si),
+        oxide_builtins::typed_array::TaIndexGate::NumericInvalid
+    );
+}

crates/oxide_vm/tests/test262_host_tests.rs

@@ -63,11 +63,6 @@ fn eval_script_syntax_error_is_catchable() {
 /// 未实现方法抛能力缺失错误（消息带 `not supported`），不抛 ReferenceError。
 #[test]
 fn unsupported_methods_throw_not_supported() {
-    let r =
-        eval("try { $262.detachArrayBuffer(new ArrayBuffer(8)); 'no-throw' } catch (e) { e.name + ':' + e.message }");
-    assert!(r.contains("TypeError"), "期望 TypeError，实际 {r}");
-    assert!(r.contains("not supported"), "期望能力缺失消息，实际 {r}");
-
     let r = eval("try { $262.createRealm(); 'no-throw' } catch (e) { e.name + ':' + e.message }");
     assert!(r.contains("TypeError"), "期望 TypeError，实际 {r}");
     assert!(r.contains("not supported"), "期望能力缺失消息，实际 {r}");
@@ -76,6 +71,15 @@ fn unsupported_methods_throw_not_supported() {
     assert!(r.contains("TypeError"), "期望 TypeError，实际 {r}");
 }
 
+/// `detachArrayBuffer` 真实现钉：detach 后 `detached` 访问器读 true、
+/// 非 ArrayBuffer 实参抛 TypeError。
+#[test]
+fn detach_array_buffer_detaches() {
+    assert_eq!(eval("var ab = new ArrayBuffer(8); $262.detachArrayBuffer(ab); ab.detached"), "true");
+    let r = eval("try { $262.detachArrayBuffer(1); 'no-throw' } catch (e) { e.name }");
+    assert_eq!(r, "TypeError");
+}
+
 /// `$262.gc()` 触发一次 session 回收且不抛错。
 #[test]
 fn gc_runs_without_error() {