From d7d0371e74707ee601020f67de88e091cdae2673 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=B1=B1=E5=90=B9=E8=89=B2=E5=BE=A1=E5=AE=88?=
 <85992002+KazariEX@users.noreply.github.com>
Date: Thu, 15 Aug 2024 17:49:43 +0800
Subject: [PATCH] fix(runtime-core): correct type inference for PascalCase
 emits (#11579)

fix vuejs/language-tools#4269
---
 .../dts-test/defineComponent.test-d.tsx          | 15 +++++++++++++++
 packages/runtime-core/src/componentEmits.ts      | 16 +++++++---------
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/packages-private/dts-test/defineComponent.test-d.tsx b/packages-private/dts-test/defineComponent.test-d.tsx
index 810310bac..79ce6d695 100644
--- a/packages-private/dts-test/defineComponent.test-d.tsx
+++ b/packages-private/dts-test/defineComponent.test-d.tsx
@@ -906,12 +906,15 @@ describe('emits', () => {
     emits: {
       click: (n: number) => typeof n === 'number',
       input: (b: string) => b.length > 1,
+      Focus: (f: boolean) => !!f,
     },
     setup(props, { emit }) {
       expectType<((n: number) => boolean) | undefined>(props.onClick)
       expectType<((b: string) => boolean) | undefined>(props.onInput)
+      expectType<((f: boolean) => boolean) | undefined>(props.onFocus)
       emit('click', 1)
       emit('input', 'foo')
+      emit('Focus', true)
       //  @ts-expect-error
       emit('nope')
       //  @ts-expect-error
@@ -922,6 +925,10 @@ describe('emits', () => {
       emit('input')
       //  @ts-expect-error
       emit('input', 1)
+      //  @ts-expect-error
+      emit('focus')
+      //  @ts-expect-error
+      emit('focus', true)
     },
     created() {
       this.$emit('click', 1)
@@ -936,6 +943,10 @@ describe('emits', () => {
       this.$emit('input')
       //  @ts-expect-error
       this.$emit('input', 1)
+      //  @ts-expect-error
+      this.$emit('focus')
+      //  @ts-expect-error
+      this.$emit('focus', true)
     },
     mounted() {
       // #3599
@@ -954,6 +965,10 @@ describe('emits', () => {
         this.$emit('input')
         //  @ts-expect-error
         this.$emit('input', 1)
+        //  @ts-expect-error
+        this.$emit('focus')
+        //  @ts-expect-error
+        this.$emit('focus', true)
       })
     },
   })
diff --git a/packages/runtime-core/src/componentEmits.ts b/packages/runtime-core/src/componentEmits.ts
index 4c3912e05..dddb2e945 100644
--- a/packages/runtime-core/src/componentEmits.ts
+++ b/packages/runtime-core/src/componentEmits.ts
@@ -47,15 +47,13 @@ export type EmitsToProps<T extends EmitsOptions | ComponentTypeEmits> =
       }
     : T extends ObjectEmitsOptions
       ? {
-          [K in `on${Capitalize<string & keyof T>}`]?: K extends `on${infer C}`
-            ? (
-                ...args: T[Uncapitalize<C>] extends (...args: infer P) => any
-                  ? P
-                  : T[Uncapitalize<C>] extends null
-                    ? any[]
-                    : never
-              ) => any
-            : never
+          [K in string & keyof T as `on${Capitalize<K>}`]?: (
+            ...args: T[K] extends (...args: infer P) => any
+              ? P
+              : T[K] extends null
+                ? any[]
+                : never
+          ) => any
         }
       : {}