fix(types): respect props with default on instance type when using __typeProps

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

@@ -1972,3 +1972,24 @@ createApp({}).component(
     },
   }),
 )
+
+const Comp = defineComponent({
+  props: {
+    actionText: {
+      type: {} as PropType<string>,
+      default: 'Become a sponsor',
+    },
+  },
+  __typeProps: {} as {
+    actionText?: string
+  },
+})
+
+const instance = new Comp()
+function expectString(s: string) {}
+// instance prop with default should be non-null
+expectString(instance.actionText)
+
+// public prop on $props should be optional
+// @ts-expect-error
+expectString(instance.$props.actionText)

packages/runtime-core/src/componentPublicInstance.ts

@@ -292,7 +292,7 @@ export type ComponentPublicInstance<
   C extends ComputedOptions = {},
   M extends MethodOptions = {},
   E extends EmitsOptions = {},
-  PublicProps = P,
+  PublicProps = {},
   Defaults = {},
   MakeDefaultsOptional extends boolean = false,
   Options = ComponentOptionsBase<any, any, any, any, any, any, any, any, any>,
@@ -323,7 +323,11 @@ export type ComponentPublicInstance<
     options?: WatchOptions,
   ): WatchStopHandle
 } & ExposedKeys<
-  IfAny<P, P, Omit<P, keyof ShallowUnwrapRef<B>>> &
+  IfAny<
+    P,
+    P,
+    Readonly<Defaults> & Omit<P, keyof ShallowUnwrapRef<B> | keyof Defaults>
+  > &
     ShallowUnwrapRef<B> &
     UnwrapNestedRefs<D> &
     ExtractComputedReturns<C> &