From a6125c1579f70106f5dfedffb77dcc8f6dda6f30 Mon Sep 17 00:00:00 2001
From: Alejandro Celaya <alejandro.celaya@hypothes.is>
Date: Mon, 23 Oct 2023 16:34:45 +0200
Subject: [PATCH] Migrate typing util to TypeScript

---
 src/util/{typing.js => typing.ts} | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)
 rename src/util/{typing.js => typing.ts} (57%)

diff --git a/src/util/typing.js b/src/util/typing.ts
similarity index 57%
rename from src/util/typing.js
rename to src/util/typing.ts
index b471ae285..ed182557f 100644
--- a/src/util/typing.js
+++ b/src/util/typing.ts
@@ -1,7 +1,4 @@
-/**
- * @template T
- * @typedef {import('preact').Ref<T>} Ref
- */
+import type { Ref } from 'preact';
 
 /**
  * Helper for downcasting a ref to a more specific type, where that is safe
@@ -10,12 +7,7 @@
  * This is mainly useful to cast a generic `Ref<HTMLElement>` to a more specific
  * element type (eg. `Ref<HTMLDivElement>`) for use with the `ref` prop of a JSX element.
  * Since Preact only writes to the `ref` prop, such a cast is safe.
- *
- * @template T
- * @template {T} U
- * @param {Ref<T>|undefined} ref
- * @return {Ref<U>|undefined}
  */
-export function downcastRef(ref) {
-  return /** @type {Ref<U>|undefined} */ (ref);
+export function downcastRef<T, U>(ref: Ref<T> | undefined): Ref<U> | undefined {
+  return ref as Ref<U> | undefined;
 }