fix(type): convert emits to props

types/test/v3/define-component-test.tsx

@@ -966,6 +966,47 @@ describe('emits', () => {
       }
     }
   })
+
+  // should have `onXXX` props for emits
+  const a = defineComponent({
+    props: {
+      bar: String
+    },
+    emits: {
+      foo: (n: number) => n > 0
+    },
+    setup(props) {
+      expectType<((n: number) => boolean) | undefined>(props.onFoo)
+    }
+  })
+
+  const b = defineComponent({
+    extends: a,
+    props: {
+      bar2: String
+    },
+    emits: {
+      foo2: (n: number) => n > 0
+    },
+    setup(props) {
+      expectType<((n: number) => boolean) | undefined>(props.onFoo)
+    }
+  })
+
+  defineComponent({
+    mixins: [a, b],
+    props: {
+      bar3: String
+    },
+    emits: {
+      foo3: (n: number) => n > 0
+    },
+    setup(props) {
+      expectType<((n: number) => boolean) | undefined>(props.onFoo)
+      expectType<((n: number) => boolean) | undefined>(props.onFoo2)
+      expectType<((n: number) => boolean) | undefined>(props.onFoo3)
+    }
+  })
 })
 
 // describe('componentOptions setup should be `SetupContext`', () => {

types/v3-component-options.d.ts

@@ -1,7 +1,7 @@
 import { Vue } from './vue'
 import { VNode } from './vnode'
 import { ComponentOptions as Vue2ComponentOptions } from './options'
-import { EmitsOptions, SetupContext } from './v3-setup-context'
+import { EmitsOptions, EmitsToProps, SetupContext } from './v3-setup-context'
 import { Data, LooseRequired, UnionToIntersection } from './common'
 import {
   ComponentPropsOptions,
@@ -52,7 +52,7 @@ export type SetupFunction<
   Emits extends EmitsOptions = {}
 > = (
   this: void,
-  props: Readonly<Props>,
+  props: Readonly<Props & EmitsToProps<Emits>>,
   ctx: SetupContext<Emits>
 ) => RawBindings | (() => VNode | null) | void
 

types/v3-define-component.d.ts

@@ -17,7 +17,7 @@ import {
   CreateComponentPublicInstance
 } from './v3-component-public-instance'
 import { Data, HasDefined } from './common'
-import { EmitsOptions } from './v3-setup-context'
+import { EmitsOptions, EmitsToProps } from './v3-setup-context'
 import { CreateElement, RenderContext } from './umd'
 
 export type DefineComponent<
@@ -31,9 +31,9 @@ export type DefineComponent<
   E extends EmitsOptions = {},
   EE extends string = string,
   Props = Readonly<
-    PropsOrPropOptions extends ComponentPropsOptions
+    (PropsOrPropOptions extends ComponentPropsOptions
       ? ExtractPropTypes<PropsOrPropOptions>
-      : PropsOrPropOptions
+      : PropsOrPropOptions) & EmitsToProps<E>
   >,
   Defaults = ExtractDefaultPropTypes<PropsOrPropOptions>
 > = ComponentPublicInstanceConstructor<

types/v3-setup-context.d.ts

@@ -13,6 +13,25 @@ export type ObjectEmitsOptions = Record<
 
 export type EmitsOptions = ObjectEmitsOptions | string[]
 
+export type EmitsToProps<T extends EmitsOptions> = T extends string[]
+  ? {
+      [K in string & `on${Capitalize<T[number]>}`]?: (...args: any[]) => any
+    }
+  : T extends ObjectEmitsOptions
+  ? {
+      [K in string &
+        `on${Capitalize<string & keyof T>}`]?: K extends `on${infer C}`
+        ? T[Uncapitalize<C>] extends null
+          ? (...args: any[]) => any
+          : (
+              ...args: T[Uncapitalize<C>] extends (...args: infer P) => any
+                ? P
+                : never
+            ) => any
+        : never
+    }
+  : {}
+
 export type EmitFn<
   Options = ObjectEmitsOptions,
   Event extends keyof Options = keyof Options,