From ad6874cd23665e67ef87801032fe943725393e86 Mon Sep 17 00:00:00 2001
From: pjh456 <147148383@qq.com>
Date: Sat, 26 Sep 2026 21:26:11 +0000
Subject: [PATCH] =?UTF-8?q?fix:=20Boolean=20=E6=9E=84=E9=80=A0=E5=99=A8?=
 =?UTF-8?q?=E5=AF=B9=E8=B1=A1=E8=87=82=E6=8C=89=20B.3.4=20=E7=89=B9?=
 =?UTF-8?q?=E5=88=A4=20DDA=20=E5=AE=BF=E4=B8=BB=E5=AF=B9=E8=B1=A1=E4=B8=BA?=
 =?UTF-8?q?=20falsy?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 crates/oxide_builtins/src/boolean.rs         |  4 ++-
 crates/oxide_builtins/tests/boolean_tests.rs | 32 ++++++++++++++++++++
 2 files changed, 35 insertions(+), 1 deletion(-)
 create mode 100644 crates/oxide_builtins/tests/boolean_tests.rs

diff --git a/crates/oxide_builtins/src/boolean.rs b/crates/oxide_builtins/src/boolean.rs
index 924900c0..7dc08fb4 100644
--- a/crates/oxide_builtins/src/boolean.rs
+++ b/crates/oxide_builtins/src/boolean.rs
@@ -18,7 +18,9 @@ pub fn boolean_constructor<H: VmHost>(vm: &mut H, args: &[u8]) -> NativeResult {
             // SAFETY: arg 已确认是字符串值。
             !unsafe { (*arg.as_string_ptr()).is_empty() }
         } else if arg.is_object() {
-            true
+            // [[IsHTMLDDA]] 宿主对象按 undefined 处理（B.3.4），falsy。
+            // SAFETY: arg 已确认是对象值，借用即时消费。
+            !unsafe { (*arg.as_js_object_ptr()).is_html_dda_obj() }
         } else if arg.is_int() {
             arg.as_int() != 0
         } else if arg.is_double() {
diff --git a/crates/oxide_builtins/tests/boolean_tests.rs b/crates/oxide_builtins/tests/boolean_tests.rs
new file mode 100644
index 00000000..034c3ec5
--- /dev/null
+++ b/crates/oxide_builtins/tests/boolean_tests.rs
@@ -0,0 +1,32 @@
+use std::sync::Arc;
+
+use oxide_compiler::compiler::Compiler;
+use oxide_types::value::JsValue;
+use oxide_vm::vm::Vm;
+
+fn eval(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))?;
+    let mut vm = Vm::new();
+    vm.run(&Arc::new(module))
+}
+
+/// 求值一个应得布尔结果的表达式并断言其类型。
+fn eval_bool(source: &str) -> bool {
+    let result = eval(source).expect("eval should succeed");
+    assert!(result.is_bool(), "expected boolean result, got {result:?}");
+    result.as_bool()
+}
+
+/// [[IsHTMLDDA]] 宿主对象按 undefined 处理（B.3.4），Boolean() 应返 false。
+#[test]
+fn boolean_html_dda_is_falsy() {
+    assert!(!eval_bool("Boolean($262.IsHTMLDDA)"));
+}
+
+/// 普通对象在 ToBoolean 下保持 truthy。
+#[test]
+fn boolean_plain_object_is_truthy() {
+    assert!(eval_bool("Boolean({})"));
+}