fix: avoid accessing undeclared instance fields on type level (vuejs#189)

* fix: avoid accessing undeclared instance fields on type level

* fix: inherit vue constructor type for constructor proxy

fix vuejs#187 
fix vuejs#185

Author: ktsn

src/component/component.ts

@@ -22,8 +22,8 @@ export type ComponentRenderProxy<P = {}, S = {}, PublicProps = P> = {
   S;
 
 // for Vetur and TSX support
-type VueConstructorProxy<PropsOptions, RawBindings> = {
-  new (): ComponentRenderProxy<
+type VueConstructorProxy<PropsOptions, RawBindings> = VueConstructor & {
+  new (...args: any[]): ComponentRenderProxy<
     ExtractPropTypes<PropsOptions>,
     UnwrapRef<RawBindings>,
     ExtractPropTypes<PropsOptions, false>
@@ -65,15 +65,15 @@ interface ComponentOptionsWithProps<
   setup?: SetupFunction<Props, RawBindings>;
 }
 
-interface ComponentOptionsWithoutProps<Props = never, RawBindings = Data> {
+interface ComponentOptionsWithoutProps<Props = unknown, RawBindings = Data> {
   props?: undefined;
   setup?: SetupFunction<Props, RawBindings>;
 }
 
 // overload 1: object format with no props
 export function createComponent<RawBindings>(
-  options: ComponentOptionsWithoutProps<never, RawBindings>
-): VueProxy<never, RawBindings>;
+  options: ComponentOptionsWithoutProps<unknown, RawBindings>
+): VueProxy<unknown, RawBindings>;
 // overload 2: object format with object props declaration
 // see `ExtractPropTypes` in ./componentProps.ts
 export function createComponent<

test/types/createComponent.spec.ts

@@ -89,7 +89,7 @@ describe('createComponent', () => {
     const App = createComponent({
       setup(props, ctx) {
         isTypeEqual<SetupContext, typeof ctx>(true);
-        isTypeEqual<never, typeof props>(true);
+        isTypeEqual<unknown, typeof props>(true);
         return () => null;
       },
     });