From 9c9f8e885a6e7d1d1651998e3761345b091df3fd Mon Sep 17 00:00:00 2001
From: Kirill Romanov <djaler1@gmail.com>
Date: Tue, 5 Oct 2021 03:19:19 +0300
Subject: [PATCH] fix: correct prop type inference when using PropType<unknown>
 (#825)

---
 src/component/componentProps.ts    | 4 +++-
 test-dts/defineComponent.test-d.ts | 7 +++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/component/componentProps.ts b/src/component/componentProps.ts
index bcd7e737..d522f2ff 100644
--- a/src/component/componentProps.ts
+++ b/src/component/componentProps.ts
@@ -63,7 +63,9 @@ type InferPropType<T> = T extends null
                 ? Function
                 : T extends Prop<infer V, infer D>
                   ? unknown extends V
-                    ? D
+                    ? D extends null | undefined
+                      ? V
+                      : D
                     : ExtractCorrectPropType<V>
                   : T
 
diff --git a/test-dts/defineComponent.test-d.ts b/test-dts/defineComponent.test-d.ts
index 8856d832..f1305dfb 100644
--- a/test-dts/defineComponent.test-d.ts
+++ b/test-dts/defineComponent.test-d.ts
@@ -28,6 +28,7 @@ describe('with object props', () => {
     ffff: (a: number, b: string) => { a: boolean }
     validated?: string
     date: Date
+    unknown: unknown
   }
 
   type GT = string & { __brand: unknown }
@@ -100,6 +101,10 @@ describe('with object props', () => {
         type: Date,
         required: true,
       },
+      unknown: {
+        type: Object as PropType<unknown>,
+        default: null,
+      },
     },
     setup(props) {
       // type assertion. See https://github.com/SamVerschueren/tsd
@@ -121,6 +126,7 @@ describe('with object props', () => {
       expectType<ExpectedProps['ffff']>(props.ffff)
       expectType<ExpectedProps['validated']>(props.validated)
       expectType<ExpectedProps['date']>(props.date)
+      expectType<typeof props.unknown>({} as ExpectedProps['unknown'])
 
       isNotAnyOrUndefined(props.a)
       isNotAnyOrUndefined(props.b)
@@ -171,6 +177,7 @@ describe('with object props', () => {
       expectType<ExpectedProps['hhh']>(props.hhh)
       expectType<ExpectedProps['ffff']>(props.ffff)
       expectType<ExpectedProps['validated']>(props.validated)
+      expectType<typeof props.unknown>({} as ExpectedProps['unknown'])
 
       // @ts-expect-error props should be readonly
       expectError((props.a = 1))