From 040e2ee6b13d829270a4ca1acae95518c4dae691 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=88=B1=E7=89=B9=E6=AF=8F=E7=BE=8A=E9=98=9F?=
 <t2026104239910027@eduxiji.net>
Date: Sat, 27 Jun 2026 11:22:37 +0800
Subject: [PATCH] =?UTF-8?q?feat:=20ToPrimitive=20=E9=93=BE=E6=94=AF?=
 =?UTF-8?q?=E6=8C=81=20Symbol.toPrimitive?=
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---
 crates/oxide_runtime_api/src/lib.rs | 47 +++++++++++++++++++++++++++++
 crates/oxide_vm/src/vm.rs           | 27 +++++++++++++++++
 2 files changed, 74 insertions(+)

diff --git a/crates/oxide_runtime_api/src/lib.rs b/crates/oxide_runtime_api/src/lib.rs
index 1f26cdc..6287f9f 100644
--- a/crates/oxide_runtime_api/src/lib.rs
+++ b/crates/oxide_runtime_api/src/lib.rs
@@ -448,3 +448,50 @@ pub fn to_object<H: VmHost>(val: JsValue, host: &mut H) -> Result<JsValue, Strin
     obj_ref.set_prop_count(1);
     Ok(obj_val)
 }
+
+/// Hint for the abstract ToPrimitive operation (ECMA-262 §7.1.1).
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum ToPrimitiveHint {
+    Default,
+    String,
+    Number,
+}
+
+impl ToPrimitiveHint {
+    /// OrdinaryToPrimitive method-name ordering hint: `Default`/`Number` -> "number", `String` -> "string".
+    pub fn as_str(self) -> &'static str {
+        match self {
+            ToPrimitiveHint::String => "string",
+            ToPrimitiveHint::Default | ToPrimitiveHint::Number => "number",
+        }
+    }
+}
+
+/// ToPrimitive(input, hint) per ECMA-262 §7.1.1.
+///
+/// Primitives pass through unchanged. Objects are coerced via the VM's
+/// `coerce_primitive_bounded`, which consults `obj[Symbol.toPrimitive]` first and
+/// otherwise runs OrdinaryToPrimitive (valueOf/toString in hint order). Keeping the
+/// object path in one place avoids duplicating OrdinaryToPrimitive here.
+pub fn to_primitive<H: VmHost>(val: JsValue, hint: ToPrimitiveHint, host: &mut H) -> Result<JsValue, String> {
+    if !val.is_object() {
+        return Ok(val);
+    }
+    host.coerce_primitive_bounded(val, hint == ToPrimitiveHint::String)
+}
+
+/// ToNumber(input) with full object coercion: objects go through ToPrimitive
+/// (number hint); Symbol values throw a TypeError per spec.
+pub fn to_number_full<H: VmHost>(val: JsValue, host: &mut H) -> Result<f64, String> {
+    let primitive = to_primitive(val, ToPrimitiveHint::Number, host)?;
+    if primitive.is_symbol() {
+        return Err(host.error_message_text("TypeError", "Cannot convert a Symbol value to a number"));
+    }
+    Ok(to_number(primitive))
+}
+
+/// ToString(input) with full object coercion: objects go through ToPrimitive (string hint).
+pub fn to_string_full<H: VmHost>(val: JsValue, host: &mut H) -> Result<String, String> {
+    let primitive = to_primitive(val, ToPrimitiveHint::String, host)?;
+    Ok(to_string(primitive))
+}
diff --git a/crates/oxide_vm/src/vm.rs b/crates/oxide_vm/src/vm.rs
index c57f3d6..8b69499 100644
--- a/crates/oxide_vm/src/vm.rs
+++ b/crates/oxide_vm/src/vm.rs
@@ -195,6 +195,33 @@ impl Vm {
             return Ok(value);
         }
 
+        // ECMA-262 §7.1.1 step 1: an exotic obj[Symbol.toPrimitive] takes precedence
+        // over OrdinaryToPrimitive. ponytail: symbol-object keys all collapse to
+        // to_string()="[object]" inside property_key_si (an engine-wide symbol-key
+        // limitation), so this resolves obj[@@toPrimitive] the same way the setter
+        // stores it; the real fix belongs to a dedicated symbol-key phase.
+        let sym_key = {
+            let sym_ptr = self.session.builtin_world().sym_to_primitive.as_ptr() as *mut JsObject;
+            JsValue::from_js_object(sym_ptr)
+        };
+        let sym_si = self.property_key_si(sym_key);
+        let exotic = {
+            let obj = unsafe { &*obj_ptr };
+            self.ordinary_get(obj, sym_si, value)?
+        };
+        if !exotic.is_undefined() && !exotic.is_null() {
+            let exotic_ptr = exotic.as_js_object_ptr();
+            if !exotic.is_object() || exotic_ptr.is_null() || !unsafe { &*exotic_ptr }.is_function() {
+                return Err(self.error_message_text("TypeError", "Symbol.toPrimitive is not a function"));
+            }
+            let hint_val = self.new_string(if prefer_string { "string" } else { "number" });
+            let result = self.call_function_sync(exotic, value, &[hint_val])?;
+            if result.is_object() {
+                return Err(self.error_message_text("TypeError", "Cannot convert object to primitive value"));
+            }
+            return Ok(result);
+        }
+
         let method_names = if prefer_string { ["toString", "valueOf"] } else { ["valueOf", "toString"] };
 
         for method_name in method_names {