From 445837851bd8e8395f1de2358fe55fb3b967988d Mon Sep 17 00:00:00 2001
From: Anna Henningsen <anna@addaleax.net>
Date: Wed, 23 Oct 2019 16:06:16 +0200
Subject: [PATCH] async_hooks: only emit `after` for AsyncResource if stack not
 empty

We clear the async id stack inside the uncaught exception handler and
emit `after` events in the process, so we should not emit `after`
a second time from the `runInAsyncScope()` code.

This should match the behaviour we have in C++.

Fixes: https://github.com/nodejs/node/issues/30080

PR-URL: https://github.com/nodejs/node/pull/30087
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>
---
 lib/async_hooks.js                            |  4 ++-
 ...est-queue-microtask-uncaught-asynchooks.js | 36 +++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)
 create mode 100644 test/parallel/test-queue-microtask-uncaught-asynchooks.js

diff --git a/lib/async_hooks.js b/lib/async_hooks.js
index 0c177055364e41..c18a902c2ace84 100644
--- a/lib/async_hooks.js
+++ b/lib/async_hooks.js
@@ -17,6 +17,7 @@ const {
   executionAsyncId,
   triggerAsyncId,
   // Private API
+  hasAsyncIdStack,
   getHookArrays,
   enableHooks,
   disableHooks,
@@ -172,7 +173,8 @@ class AsyncResource {
         return fn(...args);
       return Reflect.apply(fn, thisArg, args);
     } finally {
-      emitAfter(asyncId);
+      if (hasAsyncIdStack())
+        emitAfter(asyncId);
     }
   }
 
diff --git a/test/parallel/test-queue-microtask-uncaught-asynchooks.js b/test/parallel/test-queue-microtask-uncaught-asynchooks.js
new file mode 100644
index 00000000000000..ee64c6e68ab7ab
--- /dev/null
+++ b/test/parallel/test-queue-microtask-uncaught-asynchooks.js
@@ -0,0 +1,36 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const async_hooks = require('async_hooks');
+
+// Regression test for https://github.com/nodejs/node/issues/30080:
+// An uncaught exception inside a queueMicrotask callback should not lead
+// to multiple after() calls for it.
+
+let µtaskId;
+const events = [];
+
+async_hooks.createHook({
+  init(id, type, triggerId, resoure) {
+    if (type === 'Microtask') {
+      µtaskId = id;
+      events.push('init');
+    }
+  },
+  before(id) {
+    if (id === µtaskId) events.push('before');
+  },
+  after(id) {
+    if (id === µtaskId) events.push('after');
+  },
+  destroy(id) {
+    if (id === µtaskId) events.push('destroy');
+  }
+}).enable();
+
+queueMicrotask(() => { throw new Error(); });
+
+process.on('uncaughtException', common.mustCall());
+process.on('exit', () => {
+  assert.deepStrictEqual(events, ['init', 'after', 'before', 'destroy']);
+});