fix(types): correct handling of required props with undefined type

Author: jh-leong

packages-private/dts-test/defineComponent.test-d.tsx

@@ -22,6 +22,7 @@ describe('with object props', () => {
     a?: number | undefined
     aa: number
     aaa: number | null
+    aaaa: number | undefined
     b: string
     e?: Function
     h: boolean
@@ -63,6 +64,11 @@ describe('with object props', () => {
       type: Number as PropType<number | null>,
       default: 1,
     },
+    aaaa: {
+      type: Number as PropType<number | undefined>,
+      // `as const` prevents widening to `boolean` (keeps literal `true` type)
+      required: true as const,
+    },
     // required should make property non-void
     b: {
       type: String,
@@ -158,6 +164,11 @@ describe('with object props', () => {
       expectType<ExpectedProps['a']>(props.a)
       expectType<ExpectedProps['aa']>(props.aa)
       expectType<ExpectedProps['aaa']>(props.aaa)
+
+      // @ts-expect-error should included `undefined`
+      expectType<number>(props.aaaa)
+      expectType<ExpectedProps['aaaa']>(props.aaaa)
+
       expectType<ExpectedProps['b']>(props.b)
       expectType<ExpectedProps['e']>(props.e)
       expectType<ExpectedProps['h']>(props.h)
@@ -285,6 +296,7 @@ describe('with object props', () => {
   expectType<JSX.Element>(
     <MyComponent
       a={1}
+      aaaa={1}
       b="b"
       bb="bb"
       e={() => {}}
@@ -311,6 +323,7 @@ describe('with object props', () => {
 
   expectType<Component>(
     <MyComponent
+      aaaa={1}
       b="b"
       dd={{ n: 1 }}
       ddd={['ddd']}

packages/runtime-core/src/componentProps.ts

@@ -143,7 +143,9 @@ type InferPropType<T, NullAsAny = true> = [T] extends [null]
 export type ExtractPropTypes<O> = {
   // use `keyof Pick<O, RequiredKeys<O>>` instead of `RequiredKeys<O>` to
   // support IDE features
-  [K in keyof Pick<O, RequiredKeys<O>>]: Exclude<InferPropType<O[K]>, undefined>
+  [K in keyof Pick<O, RequiredKeys<O>>]: O[K] extends { default: any }
+    ? Exclude<InferPropType<O[K]>, undefined>
+    : InferPropType<O[K]>
 } & {
   // use `keyof Pick<O, OptionalKeys<O>>` instead of `OptionalKeys<O>` to
   // support IDE features