kerosene-ui: Make the UnwrapComponent utility type actually recursive

Author: nhardy

packages/kerosene-ui/src/types/index.ts

@@ -1,34 +1,21 @@
 /**
- * Used internally by `UnwrapComponent<T>` to unwrap a single layer decorator-wrapped component
- * @private
+ * Unwraps the decorated typings from a decorator-wrapped components to provide the original type of the underlying
+ * component. Useful in unit testing when stubbing decorators with the identity function.
  */
-export type _UnwrapComponent<T> = T extends React.MemoExoticComponent<
+type UnwrapComponent<T> = T extends React.MemoExoticComponent<
   infer TMemoComponent
 >
-  ? TMemoComponent
+  ? { 0: UnwrapComponent<TMemoComponent> }[TMemoComponent extends any
+      ? 0
+      : never]
   : T extends React.LazyExoticComponent<infer TLazyComponent>
-  ? TLazyComponent
+  ? { 0: UnwrapComponent<TLazyComponent> }[TLazyComponent extends any
+      ? 0
+      : never]
   : "WrappedComponent" extends keyof T
-  // @ts-ignore
-  ? T["WrappedComponent"]
+  ? {
+      // @ts-ignore
+      0: UnwrapComponent<T["WrappedComponent"]>;
+      // @ts-ignore
+    }[T["WrappedComponent"] extends any ? 0 : never]
   : T;
-
-/**
- * Unwraps the decorated typings from a decorator-wrapped components to provide the original type of the underlying
- * component. Useful in unit testing when stubbing decorators with the identity function.
- *
- * Note: This will unwrap up to 8 layers of decorators as although TypeScript supports recursive types, it does not
- * allow recursive type arguments. If more levels are required, you may use the `_UnwrapComponent<T>` type to unwrap
- * a single layer at a time.
- */
-export type UnwrapComponent<T> = _UnwrapComponent<
-  _UnwrapComponent<
-    _UnwrapComponent<
-      _UnwrapComponent<
-        _UnwrapComponent<
-          _UnwrapComponent<_UnwrapComponent<_UnwrapComponent<T>>>
-        >
-      >
-    >
-  >
->;