fix(runtime-core): return boolean type when use defineProps to set optional boolean prop

packages/runtime-core/src/apiSetupHelpers.ts

@@ -58,7 +58,19 @@ export function defineProps<
   PP extends ComponentObjectPropsOptions = ComponentObjectPropsOptions
 >(props: PP): Readonly<ExtractPropTypes<PP>>
 // overload 3: typed-based declaration
-export function defineProps<TypeProps>(): Readonly<TypeProps>
+// the Boolean absent props will be cast to false, so the return type
+// must be a boolean type
+export function defineProps<TypeProps>(): Readonly<
+  {
+    [K in keyof TypeProps as TypeProps[K] extends boolean | undefined
+      ? K
+      : never]-?: NotUndefined<TypeProps[K]>
+  } & {
+    [K in keyof TypeProps as TypeProps[K] extends boolean | undefined
+      ? never
+      : K]: TypeProps[K]
+  }
+>
 // implementation
 export function defineProps() {
   if (__DEV__) {
@@ -142,13 +154,27 @@ type InferDefault<P, T> = T extends
   ? T | ((props: P) => T)
   : (props: P) => T
 
-type PropsWithDefaults<Base, Defaults> = Base & {
-  [K in keyof Defaults]: K extends keyof Base
+type PropsWithDefaults<Base, Defaults> = {
+  [K in keyof Base as K extends keyof Defaults
+    ? Defaults[K] extends undefined
+      ? never
+      : K
+    : K]: Base[K];
+} & {
+  [K in keyof Base as K extends keyof Defaults
+    ? Defaults[K] extends undefined
+      ? K
+      : never
+    : never]?: Base[K] | undefined;
+} & Readonly<{
+  [K in keyof Defaults as Defaults[K] extends undefined
+    ? never
+    : K]: K extends keyof Base
     ? Defaults[K] extends undefined
       ? Base[K]
       : NotUndefined<Base[K]>
-    : never
-}
+    : never;
+}>
 
 /**
  * Vue `<script setup>` compiler macro for providing props default values when

test-dts/setupHelpers.test-d.ts

@@ -13,16 +13,23 @@ describe('defineProps w/ type declaration', () => {
   // type declaration
   const props = defineProps<{
     foo: string
+    bool?: boolean
+    boolAndUndefined: boolean | undefined
   }>()
   // explicitly declared type should be refined
   expectType<string>(props.foo)
+  // the Boolean absent props will be cast to false
+  expectType<boolean>(props.bool)
+  expectType<boolean>(props.boolAndUndefined)
   // @ts-expect-error
   props.bar
 })
 
 describe('defineProps w/ type declaration + withDefaults', () => {
   const res = withDefaults(
     defineProps<{
+      bool?: boolean
+      boolAndUndefined: boolean | undefined
       number?: number
       arr?: string[]
       obj?: { x: number }
@@ -33,6 +40,7 @@ describe('defineProps w/ type declaration + withDefaults', () => {
       z?: string
     }>(),
     {
+      bool: undefined,
       number: 123,
       arr: () => [],
       obj: () => ({ x: 123 }),
@@ -53,6 +61,8 @@ describe('defineProps w/ type declaration + withDefaults', () => {
   // @ts-expect-error
   res.y.slice()
 
+  expectType<boolean | undefined>(res.bool)
+  expectType<boolean | undefined>(res.boolAndUndefined)
   expectType<string | undefined>(res.x)
   expectType<string | undefined>(res.y)
   expectType<string>(res.z)
@@ -70,7 +80,7 @@ describe('defineProps w/ union type declaration + withDefaults', () => {
       union1: 123,
       union2: () => [123],
       union3: () => ({ x: 123 }),
-      union4: () => 123,
+      union4: () => 123
     }
   )
 })