feat: 九原型新增 toSource 遗留扩展方法

Cargo.lock

@@ -1160,7 +1160,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_builtins"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "chrono",
  "fast-float",
@@ -1185,7 +1185,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_bytecode"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "num-bigint",
  "oxide_log",
@@ -1193,7 +1193,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_cfg"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "oxide_bytecode",
  "oxide_emit",
@@ -1204,7 +1204,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_cli"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "ansi_term",
  "bumpalo",
@@ -1226,7 +1226,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_code_cache"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "lru",
  "oxide_bytecode",
@@ -1235,7 +1235,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_compiler"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1255,7 +1255,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_dce"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1269,7 +1269,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_emit"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "num-bigint",
  "oxc_allocator",
@@ -1284,7 +1284,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_engine"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "oxide_bytecode",
  "oxide_compiler",
@@ -1296,7 +1296,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_ir"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "oxide_bytecode",
  "oxide_log",
@@ -1305,7 +1305,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_kernel"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "bumpalo",
  "dashmap",
@@ -1319,7 +1319,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_liveness"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1331,7 +1331,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_log"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "tracing",
  "tracing-appender",
@@ -1340,7 +1340,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_parser"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "oxc_allocator",
  "oxc_ast",
@@ -1355,7 +1355,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_regalloc"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1371,7 +1371,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_runtime_api"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "num-bigint",
  "num-traits",
@@ -1384,7 +1384,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_test262"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "oxide_bytecode",
  "oxide_compiler",
@@ -1402,7 +1402,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_types"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "bumpalo",
  "dashmap",
@@ -1415,7 +1415,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_vm"
-version = "0.8.100"
+version = "0.8.101"
 dependencies = [
  "bumpalo",
  "chrono",

Cargo.toml

@@ -23,7 +23,7 @@ members = [
 ]
 
 [workspace.package]
-version = "0.8.100"
+version = "0.8.101"
 edition = "2021"
 license = "MIT"
 rust-version = "1.80"

crates/oxide_builtins/src/lib.rs

@@ -75,6 +75,8 @@ pub mod symbol;
 pub mod ta_codec;
 /// Temporal 内置对象实现（目录模块树：Now / Instant / PlainDate / PlainTime / PlainDateTime / PlainMonthDay / PlainYearMonth / ZonedDateTime / Duration）。
 pub mod temporal;
+/// toSource 遗留扩展（九原型 own 方法与 null/undefined this 门禁）。
+pub mod to_source;
 /// TypedArray 内置对象实现（元素访问、fill/slice/subarray/set 等）。
 pub mod typed_array;
 /// WeakMap 条目表实现（弱键 → 强值盒与 GC 六站点接线函数族）。

crates/oxide_builtins/src/to_source.rs

@@ -0,0 +1,173 @@
+//! toSource（SpiderMonkey 遗留扩展）：Object / Function / Array / String / Boolean /
+//! Number / Date / RegExp / Error 九原型各一个 own 方法。
+//!
+//! 关键约定：
+//! - 门禁统一走 CheckObjectCoercible 口径——this 为 null / undefined 抛 TypeError，
+//!   其余原始值与原对象放行；
+//! - 返回值取最小合理源码串（不追求 SpiderMonkey 完整序列化）：Function 空串、
+//!   Object / Array 恒形、String 带引号、Boolean / Number 字面量、Date / Error 构造形、
+//!   RegExp 斜杠形；
+//! - 本模块不提供 test262 度量面，验收靠单测钉 own 存在性与门禁抛错。
+
+use oxide_runtime_api::{NativeResult, VmHost};
+use oxide_types::value::JsValue;
+
+/// 九原型 toSource 共享门禁：this 为 null / undefined 抛 TypeError（CheckObjectCoercible
+/// 口径），其余原样返回 this 值供各臂消费。
+fn to_source_check_this<H: VmHost>(vm: &mut H, args: &[u8]) -> Result<JsValue, JsValue> {
+    let this_val = vm.reg(args[0]);
+    if this_val.is_null() || this_val.is_undefined() {
+        return Err(crate::error::create_type_error(vm, "toSource called on null or undefined"));
+    }
+    Ok(this_val)
+}
+
+/// `Object.prototype.toSource`：门禁后恒返 `"{}"`。
+pub fn to_source_object<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
+    if let Err(err) = to_source_check_this(vm, args) {
+        return NativeResult::Err(err);
+    }
+    NativeResult::Ok(vm.new_string_owned("{}".to_string()))
+}
+
+/// `Function.prototype.toSource`：引擎无函数源文本，门禁后恒返空串（不抛错）。
+pub fn to_source_function<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
+    if let Err(err) = to_source_check_this(vm, args) {
+        return NativeResult::Err(err);
+    }
+    NativeResult::Ok(vm.new_string_owned(String::new()))
+}
+
+/// `Array.prototype.toSource`：门禁后恒返 `"[]"`。
+pub fn to_source_array<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
+    if let Err(err) = to_source_check_this(vm, args) {
+        return NativeResult::Err(err);
+    }
+    NativeResult::Ok(vm.new_string_owned("[]".to_string()))
+}
+
+/// `String.prototype.toSource`：门禁后读 this 串值，双引号包裹返回。
+///
+/// # 边界与前提
+/// - this 为字符串时直读单元文本；非字符串走完整 ToString（对象经 ToPrimitive，
+///   用户转换异常原样传播）。
+pub fn to_source_string<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
+    let this_val = match to_source_check_this(vm, args) {
+        Ok(v) => v,
+        Err(err) => return NativeResult::Err(err),
+    };
+    let text = if this_val.is_string() {
+        vm.lookup_str(this_val).unwrap_or_default()
+    } else {
+        match oxide_runtime_api::to_string_full(this_val, vm) {
+            Ok(s) => s,
+            Err(e) => return NativeResult::Err(crate::iterator::engine_error(vm, &e)),
+        }
+    };
+    NativeResult::Ok(vm.new_string_owned(format!("\"{}\"", text)))
+}
+
+/// `Boolean.prototype.toSource`：门禁后按 ToBoolean 判位，返 `"true"` / `"false"`。
+pub fn to_source_boolean<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
+    let this_val = match to_source_check_this(vm, args) {
+        Ok(v) => v,
+        Err(err) => return NativeResult::Err(err),
+    };
+    let b = oxide_runtime_api::to_boolean(this_val);
+    NativeResult::Ok(vm.new_string_owned(if b { "true".to_string() } else { "false".to_string() }))
+}
+
+/// `Number.prototype.toSource`：门禁后按 ToNumber 取 double，十进制字面量返回。
+///
+/// # 边界与前提
+/// - this 为 double 时直读；非 double 走完整 ToNumber（用户转换异常原样传播）。
+pub fn to_source_number<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
+    let this_val = match to_source_check_this(vm, args) {
+        Ok(v) => v,
+        Err(err) => return NativeResult::Err(err),
+    };
+    let d = if this_val.is_double() {
+        this_val.as_double()
+    } else {
+        match oxide_runtime_api::to_number_full(this_val, vm) {
+            Ok(n) => n,
+            Err(e) => return NativeResult::Err(crate::iterator::engine_error(vm, &e)),
+        }
+    };
+    NativeResult::Ok(vm.number_to_string_cached(d))
+}
+
+/// `Date.prototype.toSource`：门禁后读时间戳（prop 0），返 `new Date(<ms>)` 形；
+/// 非 Date 对象或时间戳缺失时回退 `new Date(NaN)`。
+pub fn to_source_date<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
+    let this_val = match to_source_check_this(vm, args) {
+        Ok(v) => v,
+        Err(err) => return NativeResult::Err(err),
+    };
+    let ms = if this_val.is_object() {
+        let ptr = this_val.as_js_object_ptr();
+        if !ptr.is_null() && unsafe { &*ptr }.is_date_obj() {
+            let v = unsafe { &*ptr }.get_prop_at(0);
+            if v.is_double() {
+                v.as_double()
+            } else {
+                f64::NAN
+            }
+        } else {
+            f64::NAN
+        }
+    } else {
+        f64::NAN
+    };
+    let num_text = oxide_runtime_api::js_number_to_string(ms);
+    NativeResult::Ok(vm.new_string_owned(format!("new Date({})", num_text)))
+}
+
+/// `RegExp.prototype.toSource`：门禁后读 `[[OriginalSource]]` / `[[OriginalFlags]]` 槽，
+/// 返 `/source/flags` 形；非 RegExp 对象回退 `/(?:)/`。
+pub fn to_source_regexp<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
+    let this_val = match to_source_check_this(vm, args) {
+        Ok(v) => v,
+        Err(err) => return NativeResult::Err(err),
+    };
+    if !this_val.is_object() {
+        return NativeResult::Ok(vm.new_string_owned("/(?:)/".to_string()));
+    }
+    let ptr = this_val.as_js_object_ptr();
+    if ptr.is_null() || !unsafe { &*ptr }.is_regexp_obj() {
+        return NativeResult::Ok(vm.new_string_owned("/(?:)/".to_string()));
+    }
+    let re = unsafe { &*ptr };
+    let source = vm.lookup_str(re.get_regexp_source()).unwrap_or_default();
+    let flags = vm.lookup_str(re.get_regexp_flags()).unwrap_or_default();
+    NativeResult::Ok(vm.new_string_owned(format!("/{}/{}", source, flags)))
+}
+
+/// `Error.prototype.toSource`：门禁后读 `message` 属性，返 `new Error("message")` 形；
+/// 无 message 时 message 段为空串。
+///
+/// # 边界与前提
+/// - message 经原型链 Get 读取（访问器触发，用户异常吞掉回落空串）；
+/// - message 非 undefined 时走完整 ToString（Symbol 等不可转换场景回落空串）。
+pub fn to_source_error<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
+    let this_val = match to_source_check_this(vm, args) {
+        Ok(v) => v,
+        Err(err) => return NativeResult::Err(err),
+    };
+    let mut msg = String::new();
+    if this_val.is_object() {
+        let ptr = this_val.as_js_object_ptr();
+        if !ptr.is_null() {
+            let obj = unsafe { &*ptr };
+            let si_msg = vm.perm_intern("message");
+            if let Ok(v) = vm.ordinary_get(obj, si_msg, this_val) {
+                if !v.is_undefined() {
+                    if let Ok(s) = oxide_runtime_api::to_string_full(v, vm) {
+                        msg = s;
+                    }
+                }
+            }
+        }
+    }
+    NativeResult::Ok(vm.new_string_owned(format!("new Error({:?})", msg)))
+}

crates/oxide_vm/src/bindings/bind_array.rs

@@ -67,7 +67,10 @@ pub fn bind_array(core: &Arc<KernelCore>, session: &KernelSession, global: &mut
         session.builtin_world(),
         array_proto,
         core,
-        &[("toString", oxide_builtins::array::array_to_string::<crate::vm::Vm> as *const (), 0)],
+        &[
+            ("toString", oxide_builtins::array::array_to_string::<crate::vm::Vm> as *const (), 0),
+            ("toSource", oxide_builtins::to_source::to_source_array::<crate::vm::Vm> as *const (), 0),
+        ],
     );
     // 内置原型方法不可枚举（否则会泄漏进 for-in）。
     let si = core.perm_interner().intern("toString").0;

crates/oxide_vm/src/bindings/bind_boolean.rs

@@ -29,6 +29,7 @@ pub fn bind_boolean(core: &Arc<KernelCore>, session: &KernelSession, global: &mu
                 oxide_builtins::boolean::boolean_prototype_to_string::<crate::vm::Vm> as *const (),
                 0,
             ),
+            ("toSource", oxide_builtins::to_source::to_source_boolean::<crate::vm::Vm> as *const (), 0),
         ],
     );
 

crates/oxide_vm/src/bindings/bind_date.rs

@@ -139,6 +139,7 @@ pub fn bind_date(core: &Arc<KernelCore>, session: &KernelSession, global: &mut J
                 0,
             ),
             ("valueOf", oxide_builtins::date::date_value_of::<crate::vm::Vm> as *const (), 0),
+            ("toSource", oxide_builtins::to_source::to_source_date::<crate::vm::Vm> as *const (), 0),
         ],
     );
 

crates/oxide_vm/src/bindings/bind_error.rs

@@ -135,6 +135,20 @@ pub fn bind_error(core: &Arc<KernelCore>, session: &KernelSession, global: &mut
         );
     }
 
+    // toSource 遗留扩展（Error 原型方法不走 kernel 侧 bind_error_methods，
+    // 此处独立经 apply_binding_table 安装，描述符非枚举由绑定器内置）。
+    {
+        let proto_ptr = session.builtin_world().error_proto.as_ptr() as *mut JsObject;
+        // SAFETY: error_proto 由 session 持有，存活整个 session；本块内只改其 shape/属性区，无 reset。
+        let proto = unsafe { &mut *proto_ptr };
+        super::apply_binding_table(
+            session.builtin_world(),
+            proto,
+            core,
+            &[("toSource", oxide_builtins::to_source::to_source_error::<crate::vm::Vm> as *const (), 0)],
+        );
+    }
+
     // 全局 Error 槽位既有槽原位更新（旧家族构造器指针不得滞留在属性 vec），
     // 无槽时开新槽；描述符非枚举（规范 { writable:true, enumerable:false, configurable:true }）。
     let si_err = core.perm_interner().intern("Error").0;

crates/oxide_vm/src/bindings/bind_function.rs

@@ -6,6 +6,7 @@ use oxide_kernel::shape_forge::EMPTY_SHAPE_ID;
 use oxide_types::object::{JsObject, NativeFnPtr, PropAttributes};
 use oxide_types::value::JsValue;
 
+use super::apply_binding_table;
 use super::bind_global_value;
 use super::configure_native_constructor;
 
@@ -66,6 +67,15 @@ pub fn bind_function(core: &Arc<KernelCore>, session: &KernelSession, global: &m
     // 函数对象，任何访问抛 TypeError（AddRestrictedFunctionProperties 语义）。
     bind_function_proto_restricted(core, session, proto);
 
+    // toSource 遗留扩展（Function 原型方法不走 kernel 侧 bind_function_methods，
+    // 此处独立经 apply_binding_table 安装，描述符非枚举由绑定器内置）。
+    apply_binding_table(
+        session.builtin_world(),
+        proto,
+        core,
+        &[("toSource", oxide_builtins::to_source::to_source_function::<crate::vm::Vm> as *const (), 0)],
+    );
+
     bind_global_value(core, global, "Function", JsValue::from_js_object(function_ctor));
 }
 

crates/oxide_vm/src/bindings/bind_number.rs

@@ -59,6 +59,7 @@ pub fn bind_number(core: &Arc<KernelCore>, session: &KernelSession, global: &mut
                 0,
             ),
             ("valueOf", oxide_builtins::number::number_value_of::<crate::vm::Vm> as *const (), 0),
+            ("toSource", oxide_builtins::to_source::to_source_number::<crate::vm::Vm> as *const (), 0),
         ],
     );
 

crates/oxide_vm/src/bindings/bind_object.rs

@@ -86,6 +86,7 @@ pub fn bind_object(core: &Arc<KernelCore>, session: &KernelSession, global: &mut
                 oxide_builtins::object::object_proto_lookup_setter::<crate::vm::Vm> as *const (),
                 1,
             ),
+            ("toSource", oxide_builtins::to_source::to_source_object::<crate::vm::Vm> as *const (), 0),
         ],
     );
     // 内置原型方法不可枚举（否则会泄漏进 for-in）。
@@ -98,6 +99,7 @@ pub fn bind_object(core: &Arc<KernelCore>, session: &KernelSession, global: &mut
         "__defineSetter__",
         "__lookupGetter__",
         "__lookupSetter__",
+        "toSource",
     ] {
         let si = core.perm_interner().intern(name).0;
         if let Some(pos) = core.shape_forge().lookup_position(object_proto.shape_id(), si) {

crates/oxide_vm/src/bindings/bind_regexp.rs

@@ -38,6 +38,7 @@ pub fn bind_regexp(core: &Arc<KernelCore>, session: &KernelSession, global: &mut
             ("test", oxide_builtins::regexp::regexp_test::<crate::vm::Vm> as *const (), 1),
             ("toString", oxide_builtins::regexp::regexp_to_string::<crate::vm::Vm> as *const (), 0),
             ("compile", oxide_builtins::regexp::regexp_compile::<crate::vm::Vm> as *const (), 2),
+            ("toSource", oxide_builtins::to_source::to_source_regexp::<crate::vm::Vm> as *const (), 0),
         ],
     );
 

crates/oxide_vm/src/bindings/bind_string.rs

@@ -86,7 +86,10 @@ pub fn bind_string(core: &Arc<KernelCore>, session: &KernelSession, global: &mut
         session.builtin_world(),
         proto,
         core,
-        &[("toString", oxide_builtins::string::string_to_string::<crate::vm::Vm> as *const (), 0)],
+        &[
+            ("toString", oxide_builtins::string::string_to_string::<crate::vm::Vm> as *const (), 0),
+            ("toSource", oxide_builtins::to_source::to_source_string::<crate::vm::Vm> as *const (), 0),
+        ],
     );
     // String.prototype[@@iterator]：逐 code point 迭代字符；name 属性按规范
     // 落 "[Symbol.iterator]"。

crates/oxide_vm/tests/builtins_tosource_tests.rs

@@ -0,0 +1,142 @@
+//! toSource 遗留扩展（九原型 own 方法与 null/undefined this 门禁）单测。
+//!
+//! 验收面：九原型 own toSource 存在性、描述符非枚举、null/undefined/de-Reference
+//! 三形态门禁抛 TypeError、返回值形态抽查。
+
+use std::sync::Arc;
+
+use oxide_compiler::compiler::Compiler;
+use oxide_types::value::JsValue;
+use oxide_vm::vm::Vm;
+
+fn eval(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 error: {:?}", e))?;
+    let module = Compiler::new().compile(&program).map_err(|e| format!("Compile error: {}", e))?;
+    vm.run(&Arc::new(module))
+}
+
+fn to_str(vm: &Vm, val: JsValue) -> String {
+    vm.lookup_str(val).unwrap_or_default()
+}
+
+const CLASSES: [&str; 9] = ["Object", "Function", "Array", "String", "Boolean", "Number", "Date", "RegExp", "Error"];
+
+// 九原型 own toSource 存在且为函数。
+#[test]
+fn tosource_own_exists_on_nine_prototypes() {
+    let mut vm = Vm::new();
+    for cls in CLASSES {
+        let source = format!("typeof {}.prototype.toSource", cls);
+        let result = eval(&mut vm, &source).unwrap();
+        assert_eq!(to_str(&vm, result), "function", "toSource missing on {cls}");
+    }
+}
+
+// 九原型 toSource 描述符 { writable:true, enumerable:false, configurable:true }。
+#[test]
+fn tosource_descriptor_non_enumerable() {
+    let mut vm = Vm::new();
+    for cls in CLASSES {
+        let source = format!(
+            "(() => {{ var d = Object.getOwnPropertyDescriptor({}.prototype, 'toSource'); return d.writable + ',' + d.enumerable + ',' + d.configurable; }})()",
+            cls
+        );
+        let result = eval(&mut vm, &source).unwrap();
+        assert_eq!(to_str(&vm, result), "true,false,true", "descriptor wrong on {cls}");
+    }
+}
+
+// 九原型 toSource.call(null) 抛 TypeError（门禁核）。
+#[test]
+fn tosource_rejects_null_this() {
+    let mut vm = Vm::new();
+    for cls in CLASSES {
+        let source = format!(
+            "(() => {{ try {{ {}.prototype.toSource.call(null); return 'no-throw'; }} catch (e) {{ return e instanceof TypeError ? 'TypeError' : 'other'; }} }})()",
+            cls
+        );
+        let result = eval(&mut vm, &source).unwrap();
+        assert_eq!(to_str(&vm, result), "TypeError", "null this not rejected on {cls}");
+    }
+}
+
+// 九原型 toSource.call(undefined) 抛 TypeError（门禁核）。
+#[test]
+fn tosource_rejects_undefined_this() {
+    let mut vm = Vm::new();
+    for cls in CLASSES {
+        let source = format!(
+            "(() => {{ try {{ {}.prototype.toSource.call(undefined); return 'no-throw'; }} catch (e) {{ return e instanceof TypeError ? 'TypeError' : 'other'; }} }})()",
+            cls
+        );
+        let result = eval(&mut vm, &source).unwrap();
+        assert_eq!(to_str(&vm, result), "TypeError", "undefined this not rejected on {cls}");
+    }
+}
+
+// 九原型 (0, X.prototype.toSource)() de-Reference 形态抛 TypeError。
+#[test]
+fn tosource_rejects_dereference_call() {
+    let mut vm = Vm::new();
+    for cls in CLASSES {
+        let source = format!(
+            "(() => {{ try {{ (0, {}.prototype.toSource)(); return 'no-throw'; }} catch (e) {{ return e instanceof TypeError ? 'TypeError' : 'other'; }} }})()",
+            cls
+        );
+        let result = eval(&mut vm, &source).unwrap();
+        assert_eq!(to_str(&vm, result), "TypeError", "de-Reference not rejected on {cls}");
+    }
+}
+
+// 返回值形态抽查：Object/Array/Boolean/Number/String 五个最小合理形。
+#[test]
+fn tosource_return_value_forms() {
+    let mut vm = Vm::new();
+    let result = eval(&mut vm, "Object.prototype.toSource.call({})").unwrap();
+    assert_eq!(to_str(&vm, result), "{}");
+
+    let result = eval(&mut vm, "Array.prototype.toSource.call([])").unwrap();
+    assert_eq!(to_str(&vm, result), "[]");
+
+    let result = eval(&mut vm, "Boolean.prototype.toSource.call(true)").unwrap();
+    assert_eq!(to_str(&vm, result), "true");
+
+    let result = eval(&mut vm, "Number.prototype.toSource.call(42)").unwrap();
+    assert_eq!(to_str(&vm, result), "42");
+
+    let result = eval(&mut vm, "String.prototype.toSource.call('hi')").unwrap();
+    assert_eq!(to_str(&vm, result), "\"hi\"");
+}
+
+// Function 臂：引擎无函数源文本，恒返空串。
+#[test]
+fn tosource_function_returns_empty() {
+    let mut vm = Vm::new();
+    let result = eval(&mut vm, "Function.prototype.toSource.call(function(){})").unwrap();
+    assert_eq!(to_str(&vm, result), "");
+}
+
+// RegExp 臂：/source/flags 斜杠形。
+#[test]
+fn tosource_regexp_slash_form() {
+    let mut vm = Vm::new();
+    let result = eval(&mut vm, "RegExp.prototype.toSource.call(/ab+c/i)").unwrap();
+    assert_eq!(to_str(&vm, result), "/ab+c/i");
+}
+
+// Error 臂：new Error("message") 构造形。
+#[test]
+fn tosource_error_construction_form() {
+    let mut vm = Vm::new();
+    let result = eval(&mut vm, "Error.prototype.toSource.call(new Error('boom'))").unwrap();
+    assert_eq!(to_str(&vm, result), "new Error(\"boom\")");
+}
+
+// Date 臂：new Date(<ms>) 构造形。
+#[test]
+fn tosource_date_construction_form() {
+    let mut vm = Vm::new();
+    let result = eval(&mut vm, "Date.prototype.toSource.call(new Date(1234))").unwrap();
+    assert_eq!(to_str(&vm, result), "new Date(1234)");
+}