From ffa3726af5e94f34469f6555063de23c86447bd8 Mon Sep 17 00:00:00 2001
From: burgerni10 <nicolas.burger@optimistik.com>
Date: Mon, 28 Sep 2026 14:33:28 +0200
Subject: [PATCH] fix: treat private class methods as function boundaries in
 TLA detection

`detectESMFeatures` did not stop at `ClassPrivateMethod` when climbing from
an `await` / `for await`, so `await` inside `async #method()` was reported as
top-level await. Combined with exports, the module was left untransformed,
bytecode generation failed and the file was skipped from the executable
(e.g. node-opcua >= 2.184). Use Babel's `isFunction()` alias, which covers
every function-like node.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 lib/esm-transformer.ts            | 16 ++--------------
 test/unit/esm-transformer.test.ts | 15 +++++++++++++++
 2 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/lib/esm-transformer.ts b/lib/esm-transformer.ts
index fa331ad3..2939efa6 100644
--- a/lib/esm-transformer.ts
+++ b/lib/esm-transformer.ts
@@ -103,13 +103,7 @@ function detectESMFeatures(
         let isTopLevel = true;
 
         while (parent) {
-          if (
-            parent.isFunctionDeclaration() ||
-            parent.isFunctionExpression() ||
-            parent.isArrowFunctionExpression() ||
-            parent.isObjectMethod() ||
-            parent.isClassMethod()
-          ) {
+          if (parent.isFunction()) {
             isTopLevel = false;
             break;
           }
@@ -132,13 +126,7 @@ function detectESMFeatures(
           let isTopLevel = true;
 
           while (parent) {
-            if (
-              parent.isFunctionDeclaration() ||
-              parent.isFunctionExpression() ||
-              parent.isArrowFunctionExpression() ||
-              parent.isObjectMethod() ||
-              parent.isClassMethod()
-            ) {
+            if (parent.isFunction()) {
               isTopLevel = false;
               break;
             }
diff --git a/test/unit/esm-transformer.test.ts b/test/unit/esm-transformer.test.ts
index 2325f916..46141b6b 100644
--- a/test/unit/esm-transformer.test.ts
+++ b/test/unit/esm-transformer.test.ts
@@ -128,6 +128,21 @@ describe('transformESMtoCJS', () => {
     assert.doesNotMatch(res.code, /async\s*\(\s*\)\s*=>/);
   });
 
+  it('await inside a private class method does NOT trigger IIFE wrap', () => {
+    // `async #m()` is a ClassPrivateMethod, not a ClassMethod — the climber
+    // must treat it as a function boundary too, otherwise any module using
+    // private async methods is reported as TLA + exports and left untransformed.
+    const src = [
+      'export class C {',
+      '  async #m() { await 1; }',
+      '  async #n() { for await (const x of []) {} }',
+      '}',
+    ].join('\n');
+    const res = transformESMtoCJS(src, 'private-method.mjs');
+    assert.equal(res.isTransformed, true);
+    assert.doesNotMatch(res.code, /async\s*\(\s*\)\s*=>/);
+  });
+
   it('import.meta: esbuild emits shim, we inject the real implementation', () => {
     const res = transformESMtoCJS(
       'export const here = import.meta.url;\n',