From 07128b0c771f71dabb8681f5f2a0fd012ae78a78 Mon Sep 17 00:00:00 2001
From: camc314 <18101008+camc314@users.noreply.github.com>
Date: Thu, 19 Mar 2026 22:11:47 +0000
Subject: [PATCH] feat(semantic): report error for `await using` in class
 static block (#20535)

---
 crates/oxc_semantic/src/checker/javascript.rs   |  4 ++++
 crates/oxc_semantic/src/diagnostics.rs          |  6 ++++++
 tasks/coverage/snapshots/parser_typescript.snap | 12 +++++++++---
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/crates/oxc_semantic/src/checker/javascript.rs b/crates/oxc_semantic/src/checker/javascript.rs
index cf52593c7a149..ae0dbd9a9a7d4 100644
--- a/crates/oxc_semantic/src/checker/javascript.rs
+++ b/crates/oxc_semantic/src/checker/javascript.rs
@@ -561,6 +561,10 @@ pub fn check_variable_declaration(decl: &VariableDeclaration, ctx: &SemanticBuil
     {
         ctx.error(diagnostics::using_declaration_not_allowed_in_script(decl.span));
     }
+    if decl.kind.is_await() && ctx.scoping.scope_flags(ctx.current_scope_id).is_class_static_block()
+    {
+        ctx.error(diagnostics::class_static_block_await_using(decl.span));
+    }
 }
 
 pub fn check_meta_property(prop: &MetaProperty, ctx: &SemanticBuilder<'_>) {
diff --git a/crates/oxc_semantic/src/diagnostics.rs b/crates/oxc_semantic/src/diagnostics.rs
index 575069b8247cb..5c948032158f8 100644
--- a/crates/oxc_semantic/src/diagnostics.rs
+++ b/crates/oxc_semantic/src/diagnostics.rs
@@ -47,6 +47,12 @@ pub fn class_static_block_for_await(span: Span) -> OxcDiagnostic {
         .with_label(span)
 }
 
+#[cold]
+pub fn class_static_block_await_using(span: Span) -> OxcDiagnostic {
+    OxcDiagnostic::error("Cannot use 'await using' in class static initialization block")
+        .with_label(span)
+}
+
 #[cold]
 pub fn reserved_keyword(x0: &str, span1: Span) -> OxcDiagnostic {
     OxcDiagnostic::error(format!("The keyword '{x0}' is reserved")).with_label(span1)
diff --git a/tasks/coverage/snapshots/parser_typescript.snap b/tasks/coverage/snapshots/parser_typescript.snap
index c1088cc0ce063..e409bbecfdadb 100644
--- a/tasks/coverage/snapshots/parser_typescript.snap
+++ b/tasks/coverage/snapshots/parser_typescript.snap
@@ -3,7 +3,7 @@ commit: c9e7428b
 parser_typescript Summary:
 AST Parsed     : 9828/9831 (99.97%)
 Positive Passed: 9817/9831 (99.86%)
-Negative Passed: 1533/2587 (59.26%)
+Negative Passed: 1534/2587 (59.30%)
 Expect Syntax Error: tasks/coverage/typescript/tests/cases/compiler/FunctionDeclaration3.ts
 
 Expect Syntax Error: tasks/coverage/typescript/tests/cases/compiler/FunctionDeclaration4.ts
@@ -1966,8 +1966,6 @@ Expect Syntax Error: tasks/coverage/typescript/tests/cases/conformance/scanner/e
 
 Expect Syntax Error: tasks/coverage/typescript/tests/cases/conformance/scanner/ecmascript5/scannerNumericLiteral9.ts
 
-Expect Syntax Error: tasks/coverage/typescript/tests/cases/conformance/statements/VariableStatements/usingDeclarations/awaitUsingDeclarations.14.ts
-
 Expect Syntax Error: tasks/coverage/typescript/tests/cases/conformance/statements/VariableStatements/usingDeclarations/awaitUsingDeclarationsInForOf.4.ts
 
 Expect Syntax Error: tasks/coverage/typescript/tests/cases/conformance/statements/for-inStatements/for-inStatementsArrayErrors.ts
@@ -25876,6 +25874,14 @@ Expect to Parse: tasks/coverage/typescript/tests/cases/conformance/parser/ecmasc
    ╰────
   help: Wrap this code in a block or use a module
 
+  × Cannot use 'await using' in class static initialization block
+   ╭─[typescript/tests/cases/conformance/statements/VariableStatements/usingDeclarations/awaitUsingDeclarations.14.ts:3:9]
+ 2 │     static {
+ 3 │         await using x = null;
+   ·         ─────────────────────
+ 4 │         {
+   ╰────
+
   × TS(1546): 'await using' declarations are not allowed in ambient contexts.
    ╭─[typescript/tests/cases/conformance/statements/VariableStatements/usingDeclarations/awaitUsingDeclarations.16.ts:2:17]
  1 │ declare namespace N {