From bd1427b1161079dd91b6886c1f07ddf056351a81 Mon Sep 17 00:00:00 2001
From: pjh456 <147148383@qq.com>
Date: Wed, 9 Sep 2026 19:52:03 +0800
Subject: [PATCH] =?UTF-8?q?test:=20TDZ=20=E5=8D=95=E6=B5=8B=E8=A1=A5?=
 =?UTF-8?q?=E5=B5=8C=E5=A5=97=E5=9D=97/=E8=87=AA=E5=BC=95=E7=94=A8/hoisted?=
 =?UTF-8?q?=20=E8=AF=BB=E5=BD=A2=E7=8A=B6=20+=20=E5=9B=BA=E5=8C=96?=
 =?UTF-8?q?=E5=8D=95=E8=AF=AD=E5=8F=A5=E4=BD=93=20lexical=20=E5=A3=B0?=
 =?UTF-8?q?=E6=98=8E=E8=A7=A3=E6=9E=90=E6=8B=92=E7=BB=9D=E5=A5=91=E7=BA=A6?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 crates/oxide_emit/src/prepass.rs       |  5 ++--
 crates/oxide_vm/tests/scoping_tests.rs | 37 ++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/crates/oxide_emit/src/prepass.rs b/crates/oxide_emit/src/prepass.rs
index 945ce405..d6c8de2a 100644
--- a/crates/oxide_emit/src/prepass.rs
+++ b/crates/oxide_emit/src/prepass.rs
@@ -537,8 +537,9 @@ impl Emitter {
     ///
     /// # 边界与前提
     /// - 只扫描直接子语句 + 递归 switch case（switch 不推 scope，case 内 lexical
-    ///   声明属于外层作用域）；不递归块/if/for/while body（嵌套块自预声明，
-    ///   单语句 body 不含 lexical 声明）。
+    ///   声明属于外层作用域）；不递归块/if/for/while body（嵌套块自预声明；
+    ///   单语句 body 不接受 lexical 声明——lexical 属 Declaration、非 Statement
+    ///   子产生式，parser 按语法错误直接拒绝，这些形状不会进入 emit）。
     /// - 跳过 for 头声明（循环作用域由 for 分支内联 declare）。
     pub(crate) fn predeclare_lexical_declarations(&self, statements: &[Statement], ctx: &mut CompileCtx) {
         for statement in statements {
diff --git a/crates/oxide_vm/tests/scoping_tests.rs b/crates/oxide_vm/tests/scoping_tests.rs
index 5be104d3..60901751 100644
--- a/crates/oxide_vm/tests/scoping_tests.rs
+++ b/crates/oxide_vm/tests/scoping_tests.rs
@@ -158,3 +158,40 @@ fn typeof_tdz_throws() {
     let err = eval("typeof x; let x;").unwrap_err();
     assert!(err.contains("ReferenceError"), "got: {}", err);
 }
+
+#[test]
+fn tdz_nested_block_read_throws() {
+    // 嵌套块读：块内声明点前的读命中块级 TDZ 占位，抛 ReferenceError。
+    let err = eval("{ x; let x; }").unwrap_err();
+    assert!(err.contains("ReferenceError"), "got: {}", err);
+}
+
+#[test]
+fn tdz_declaration_self_reference_throws() {
+    // 声明语句自引用：初始化器读 x 时 x 尚未初始化，抛 ReferenceError。
+    let err = eval("let x = x + 1").unwrap_err();
+    assert!(err.contains("ReferenceError"), "got: {}", err);
+}
+
+#[test]
+fn tdz_hoisted_function_reads_later_let_throws() {
+    // hoisted 函数读声明点之后的 let：调用时 x 仍在 TDZ，抛 ReferenceError。
+    let err = eval("function f(){return x} f(); let x;").unwrap_err();
+    assert!(err.contains("ReferenceError"), "got: {}", err);
+}
+
+#[test]
+fn lexical_decl_in_single_statement_body_rejected_at_parse() {
+    // 文法契约：单语句体取 Statement，lexical 声明属 Declaration（非 Statement），
+    // `if (c) let x = 5;` 等无括号控制流体体直属 lexical 是语法错误，解析期即拒绝，
+    // 不会进入 emit——TDZ 窗口读在该形状上不可达。此前提若被未来 parser 变更
+    // 打破（开始接受这些形状），须同步补 lexical 预声明的体递归覆盖。
+    let err = eval("if (true) let x = 5;").unwrap_err();
+    assert!(err.contains("Parse"), "got: {}", err);
+    let err = eval("if (true) const x = 5;").unwrap_err();
+    assert!(err.contains("Parse"), "got: {}", err);
+    let err = eval("for (let i = 0; i < 1; i++) let x = 5;").unwrap_err();
+    assert!(err.contains("Parse"), "got: {}", err);
+    let err = eval("lab: let x = 5;").unwrap_err();
+    assert!(err.contains("Parse"), "got: {}", err);
+}