From 97e569aa8078b4b181640b5158c6d689aee0eb8e Mon Sep 17 00:00:00 2001
From: zhiyuanzmj <260480378@qq.com>
Date: Mon, 6 Apr 2026 19:03:03 +0800
Subject: [PATCH 1/2] fix(types): infer emits from SetupContext

---
 .../dts-test/defineComponent.test-d.tsx       |  7 ++++++
 packages/runtime-core/src/component.ts        | 22 +++++++------------
 2 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/packages-private/dts-test/defineComponent.test-d.tsx b/packages-private/dts-test/defineComponent.test-d.tsx
index 6188b102b31..585b693b4f6 100644
--- a/packages-private/dts-test/defineComponent.test-d.tsx
+++ b/packages-private/dts-test/defineComponent.test-d.tsx
@@ -1175,6 +1175,13 @@ describe('componentOptions setup should be `SetupContext`', () => {
   )
 })
 
+describe('infer emits from SetupContext', () => {
+  const Foo = defineComponent({
+    setup(_, _ctx: SetupContext<['foo']>) {},
+  })
+  ;<Foo onFoo={() => {}}></Foo>
+})
+
 describe('extract instance type', () => {
   const Base = defineComponent({
     props: {
diff --git a/packages/runtime-core/src/component.ts b/packages/runtime-core/src/component.ts
index c46741bee80..7c9a6ab661b 100644
--- a/packages/runtime-core/src/component.ts
+++ b/packages/runtime-core/src/component.ts
@@ -284,20 +284,14 @@ export type { ComponentOptions }
 
 export type LifecycleHook<TFn = Function> = (TFn & SchedulerJob)[] | null
 
-// use `E extends any` to force evaluating type to fix #2362
-export type SetupContext<
-  E = EmitsOptions,
-  S extends SlotsType = {},
-> = E extends any
-  ? {
-      attrs: Attrs
-      slots: UnwrapSlotsType<S>
-      emit: EmitFn<E>
-      expose: <Exposed extends Record<string, any> = Record<string, any>>(
-        exposed?: Exposed,
-      ) => void
-    }
-  : never
+export type SetupContext<E = EmitsOptions, S extends SlotsType = {}> = {
+  attrs: Attrs
+  slots: UnwrapSlotsType<S>
+  emit: EmitFn<E>
+  expose: <Exposed extends Record<string, any> = Record<string, any>>(
+    exposed?: Exposed,
+  ) => void
+}
 
 /**
  * @internal

From 0f93ce1a787d6a28bf156876a9a81a3707e10169 Mon Sep 17 00:00:00 2001
From: zhiyuanzmj <260480378@qq.com>
Date: Tue, 7 Apr 2026 08:20:52 +0800
Subject: [PATCH 2/2] chore: update test

---
 packages-private/dts-test/defineComponent.test-d.tsx | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/packages-private/dts-test/defineComponent.test-d.tsx b/packages-private/dts-test/defineComponent.test-d.tsx
index 585b693b4f6..12da320c244 100644
--- a/packages-private/dts-test/defineComponent.test-d.tsx
+++ b/packages-private/dts-test/defineComponent.test-d.tsx
@@ -1176,10 +1176,15 @@ describe('componentOptions setup should be `SetupContext`', () => {
 })
 
 describe('infer emits from SetupContext', () => {
+  // options
   const Foo = defineComponent({
     setup(_, _ctx: SetupContext<['foo']>) {},
   })
   ;<Foo onFoo={() => {}}></Foo>
+
+  // functional
+  const Bar = defineComponent((_, _ctx: SetupContext<['foo']>) => () => {})
+  ;<Bar onFoo={() => {}}></Bar>
 })
 
 describe('extract instance type', () => {