mark return value of range as readonly to avoid corrupting internal state

Author: webstrand

packages/range/src/repeat.ts

@@ -22,7 +22,7 @@ export function repeat<T>(
   times: Accessor<number>,
   mapFn: (i: number) => T,
   options: { fallback?: Accessor<T> } = {},
-): Accessor<T[]> {
+): Accessor<readonly T[]> {
   let prev: readonly T[] = [];
   let prevLen: number | undefined;
   const disposers: (() => void)[] = [];
@@ -35,9 +35,9 @@ export function repeat<T>(
   // Truncate toward zero and force positive
   const memoLen = createMemo(() => Math.max(times() | 0, 0));
 
-  return function mapLength(): T[] {
+  return function mapLength(): readonly T[] {
     const len = memoLen();
-    if (len === prevLen) return prev as T[];
+    if (len === prevLen) return prev;
 
     // Dispose of fallback or unnecessarry elements
     if (prevLen === 0) disposers[0]?.();