From ab1d0dc9160851d88f08ad3853b243299247a967 Mon Sep 17 00:00:00 2001
From: Benjamin Gruenbaum <benjamingr@gmail.com>
Date: Wed, 16 Feb 2022 21:36:20 +0200
Subject: [PATCH] events: set default handler value
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Event handler like BroadcastChannel.onmessage and AbortSignal.onabort
have a default value of `null` but we return `undefined`.
Return `null` and add a test.
PR-URL: https://github.com/nodejs/node/pull/41970
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Mestery <mestery@protonmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
---
lib/internal/event_target.js | 2 +-
test/parallel/test-eventtarget.js | 11 +++++++++--
2 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/lib/internal/event_target.js b/lib/internal/event_target.js
index bc6f91fbe82159..7c539db2eb3c2a 100644
--- a/lib/internal/event_target.js
+++ b/lib/internal/event_target.js
@@ -929,7 +929,7 @@ function defineEventHandler(emitter, name) {
// 8.1.5.1 Event handlers - basically `on[eventName]` attributes
ObjectDefineProperty(emitter, `on${name}`, {
get() {
- return this[kHandlers]?.get(name)?.handler;
+ return this[kHandlers]?.get(name)?.handler ?? null;
},
set(value) {
if (!this[kHandlers]) {
diff --git a/test/parallel/test-eventtarget.js b/test/parallel/test-eventtarget.js
index d3b1ee7358a104..0211dc964d253a 100644
--- a/test/parallel/test-eventtarget.js
+++ b/test/parallel/test-eventtarget.js
@@ -408,6 +408,13 @@ let asyncTest = Promise.resolve();
target.onfoo = common.mustCall();
target.dispatchEvent(new Event('foo'));
}
+
+{
+ const target = new EventTarget();
+ defineEventHandler(target, 'foo');
+ strictEqual(target.onfoo, null);
+}
+
{
const target = new EventTarget();
defineEventHandler(target, 'foo');
@@ -623,14 +630,14 @@ let asyncTest = Promise.resolve();
strictEqual(et.constructor.name, 'EventTarget');
}
{
- // Weak event handlers work
+ // Weak event listeners work
const et = new EventTarget();
const listener = common.mustCall();
et.addEventListener('foo', listener, { [kWeakHandler]: et });
et.dispatchEvent(new Event('foo'));
}
{
- // Weak event handlers can be removed and weakness is not part of the key
+ // Weak event listeners can be removed and weakness is not part of the key
const et = new EventTarget();
const listener = common.mustNotCall();
et.addEventListener('foo', listener, { [kWeakHandler]: et });