typescript-eslint · bradzacher · Jan 12, 2024 · Sep 15, 2023 · Sep 15, 2023 · Sep 15, 2023
diff --git a/packages/ast-spec/src/statement/ForInStatement/fixtures/_error_/using-initializer/fixture.ts b/packages/ast-spec/src/statement/ForInStatement/fixtures/_error_/using-initializer/fixture.ts
@@ -0,0 +1 @@
+for(using foo in {});
diff --git a/...atement/ForInStatement/fixtures/_error_/using-initializer/snapshots/1-TSESTree-Error.shot b/...atement/ForInStatement/fixtures/_error_/using-initializer/snapshots/1-TSESTree-Error.shot
diff --git a/.../statement/ForInStatement/fixtures/_error_/using-initializer/snapshots/2-Babel-Error.shot b/.../statement/ForInStatement/fixtures/_error_/using-initializer/snapshots/2-Babel-Error.shot
diff --git a/...tement/ForInStatement/fixtures/_error_/using-initializer/snapshots/3-Alignment-Error.shot b/...tement/ForInStatement/fixtures/_error_/using-initializer/snapshots/3-Alignment-Error.shot
diff --git a/packages/typescript-estree/src/convert.ts b/packages/typescript-estree/src/convert.ts
@@ -933,6 +933,7 @@ export class Converter {
         });
 
       case SyntaxKind.ForInStatement:
+        this.#checkForStatementDeclaration(node.initializer);
         return this.createNode<TSESTree.ForInStatement>(node, {
           type: AST_NODE_TYPES.ForInStatement,
           left: this.convertPattern(node.initializer),
@@ -3510,4 +3511,14 @@ export class Converter {
 
     throw createError(message, this.ast, start, end);
   }
+  #checkForStatementDeclaration(initializer: ts.ForInitializer): void {
+    if (ts.isVariableDeclarationList(initializer)) {
+      if ((initializer.flags & ts.NodeFlags.Using) !== 0) {
+        this.#throwError(
+          initializer,
+          "The left-hand side of a 'for...in' statement cannot be a 'using' declaration.",
+        );
+      }
+    }
+  }
 }