From a85e445b6f41f953884297af0b95ace4027483d2 Mon Sep 17 00:00:00 2001
From: Cold Fry <coldfry.business@gmail.com>
Date: Thu, 16 Apr 2026 14:22:20 +0000
Subject: [PATCH] apply pilaoda's fix

---
 src/transformation/utils/typescript/index.ts |  6 ++++--
 test/unit/using.spec.ts                      | 20 ++++++++++++++++++++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/src/transformation/utils/typescript/index.ts b/src/transformation/utils/typescript/index.ts
index e5984b08f..f12bf4721 100644
--- a/src/transformation/utils/typescript/index.ts
+++ b/src/transformation/utils/typescript/index.ts
@@ -14,12 +14,14 @@ export function hasExportEquals(sourceFile: ts.SourceFile): boolean {
  * Search up until finding a node satisfying the callback
  */
 export function findFirstNodeAbove<T extends ts.Node>(node: ts.Node, callback: (n: ts.Node) => n is T): T | undefined {
-    let current = node;
+    // Synthetic nodes (created by pre-transformers like usingTransformer) may have an unset .parent.
+    // Fall back to ts.getOriginalNode so we can still walk the source-parsed parent chain.
+    let current = ts.getOriginalNode(node);
     while (current.parent) {
         if (callback(current.parent)) {
             return current.parent;
         } else {
-            current = current.parent;
+            current = ts.getOriginalNode(current.parent);
         }
     }
 }
diff --git a/test/unit/using.spec.ts b/test/unit/using.spec.ts
index bfe5312b0..60364f680 100644
--- a/test/unit/using.spec.ts
+++ b/test/unit/using.spec.ts
@@ -194,6 +194,26 @@ test("await using no extra diagnostics (#1571)", () => {
     `.expectToHaveNoDiagnostics();
 });
 
+// https://github.com/TypeScriptToLua/TypeScriptToLua/issues/1622
+test("await-using with nested async arrow that also has await-using (runtime divergence)", () => {
+    util.testFunction`
+        const logs: any[] = [];
+        async function getA(): Promise<AsyncDisposable> {
+            return { [Symbol.asyncDispose]: async () => {} };
+        }
+        async function outer(): Promise<number> {
+            await using a = await getA();
+            const inner = async (): Promise<number> => {
+                await using b = await getA();
+                return 42;
+            };
+            return inner();
+        }
+        outer().then(v => logs.push(v));
+        return logs;
+    `.expectToEqual([42]);
+});
+
 // https://github.com/TypeScriptToLua/TypeScriptToLua/issues/1584
 test("works with disposable classes (#1584)", () => {
     util.testFunction`