From 06008628a2348f2825d6231cbe73ea18011bc967 Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Thu, 6 Nov 2025 11:51:35 +0800
Subject: [PATCH 1/2] types(defineProps): avoid never props becoming boolean
 flags

---
 packages-private/dts-test/setupHelpers.test-d.ts | 10 ++++++++++
 packages/runtime-core/src/apiSetupHelpers.ts     |  4 +++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/packages-private/dts-test/setupHelpers.test-d.ts b/packages-private/dts-test/setupHelpers.test-d.ts
index 656f1da79f2..0cf713ab9b1 100644
--- a/packages-private/dts-test/setupHelpers.test-d.ts
+++ b/packages-private/dts-test/setupHelpers.test-d.ts
@@ -33,6 +33,16 @@ describe('defineProps w/ type declaration', () => {
   expectType<boolean>(props.boolAndUndefined)
 })
 
+describe('defineProps w/ never prop', () => {
+  const props = defineProps<{
+    foo?: never
+    bar: number
+  }>()
+
+  expectType<never | undefined>(props.foo)
+  expectType<number>(props.bar)
+})
+
 describe('defineProps w/ generics', () => {
   function test<T extends boolean>() {
     const props = defineProps<{ foo: T; bar: string; x?: boolean }>()
diff --git a/packages/runtime-core/src/apiSetupHelpers.ts b/packages/runtime-core/src/apiSetupHelpers.ts
index 67e1d550387..7515a984610 100644
--- a/packages/runtime-core/src/apiSetupHelpers.ts
+++ b/packages/runtime-core/src/apiSetupHelpers.ts
@@ -99,7 +99,9 @@ export type DefineProps<T, BKeys extends keyof T> = Readonly<T> & {
 
 type BooleanKey<T, K extends keyof T = keyof T> = K extends any
   ? [T[K]] extends [boolean | undefined]
-    ? K
+    ? boolean extends T[K]
+      ? K
+      : never
     : never
   : never
 

From 6079bdbf0ca036e21c642bc8b22d080df9a7c60e Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Sat, 8 Nov 2025 20:04:25 +0800
Subject: [PATCH 2/2] chore: update

---
 packages/runtime-core/src/apiSetupHelpers.ts | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/runtime-core/src/apiSetupHelpers.ts b/packages/runtime-core/src/apiSetupHelpers.ts
index 7515a984610..250f4f5fea0 100644
--- a/packages/runtime-core/src/apiSetupHelpers.ts
+++ b/packages/runtime-core/src/apiSetupHelpers.ts
@@ -98,10 +98,10 @@ export type DefineProps<T, BKeys extends keyof T> = Readonly<T> & {
 }
 
 type BooleanKey<T, K extends keyof T = keyof T> = K extends any
-  ? [T[K]] extends [boolean | undefined]
-    ? boolean extends T[K]
-      ? K
-      : never
+  ? T[K] extends boolean | undefined
+    ? T[K] extends never | undefined
+      ? never
+      : K
     : never
   : never