Use object for initial cache key in memoize again

observablehq · May 26, 2022 · 30da5cb · 30da5cb
1 parent d692adb
commit 30da5cb
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/src/memoize.ts b/src/memoize.ts
@@ -1,8 +1,8 @@
 export function memoize1<R extends Array<unknown>, T>(compute: (...rest: R) => T): (...rest: R) => T {
   let cacheValue: T;
-  let cacheKeys: R | null = null;
+  let cacheKeys: R | {length?: undefined} = {};
   return (...keys: R) => {
-    if (cacheKeys?.length !== keys.length || cacheKeys.some((k, i) => k !== keys[i])) {
+    if (cacheKeys.length !== keys.length || cacheKeys.some((k, i) => k !== keys[i])) {
       cacheKeys = keys;
       cacheValue = compute(...keys);
     }