Deoptimize custom event detail (#5123)

rollup · Sep 6, 2023 · 884e678 · 884e678
1 parent c6aa575
commit 884e678
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Showing 4 changed files with 24 additions and 1 deletion.
diff --git a/src/ast/nodes/shared/knownGlobals.ts b/src/ast/nodes/shared/knownGlobals.ts
@@ -478,7 +478,17 @@ const knownGlobals: GlobalDescription = {
 	CSSSupportsRule: C,
 	CustomElementRegistry: C,
 	customElements: O,
-	CustomEvent: C,
+	CustomEvent: {
+		__proto__: null,
+		[ValueProperties]: {
+			deoptimizeArgumentsOnCall({ args }: NodeInteractionCalled) {
+				args[2]?.deoptimizePath(['detail']);
+			},
+			getLiteralValue: getTruthyLiteralValue,
+			hasEffectsWhenCalled: returnFalse
+		},
+		prototype: O
+	},
 	DataTransfer: C,
 	DataTransferItem: C,
 	DataTransferItemList: C,

diff --git a/test/form/samples/custom-event-detail/_config.js b/test/form/samples/custom-event-detail/_config.js
@@ -0,0 +1,3 @@
+module.exports = defineTest({
+	description: 'observes side effects for custom event payloads'
+});
diff --git a/test/form/samples/custom-event-detail/_expected.js b/test/form/samples/custom-event-detail/_expected.js
@@ -0,0 +1,5 @@
+const detail = { value: null };
+const event = new CustomEvent('test', { detail });
+event.detail.value = true;
+if (detail.value) console.log('ok');
+else console.log('failed');
diff --git a/test/form/samples/custom-event-detail/main.js b/test/form/samples/custom-event-detail/main.js
@@ -0,0 +1,5 @@
+const detail = { value: null };
+const event = new CustomEvent('test', { detail });
+event.detail.value = true;
+if (detail.value) console.log('ok');
+else console.log('failed');