feat(notify): throw RangeError for invalid n

Author: lambdalisue

notify.ts

@@ -35,8 +35,14 @@ export class Notify {
   /**
    * Notifies `n` waiters that are waiting for notification. Resolves each of the notified waiters.
    * If there are fewer than `n` waiters, all waiters are notified.
+   *
+   * @param n The number of waiters to notify.
+   * @throws {RangeError} if `n` is not a positive safe integer.
    */
   notify(n = 1): void {
+    if (n <= 0 || !Number.isSafeInteger(n)) {
+      throw new RangeError(`n must be a positive safe integer, got ${n}`);
+    }
     const it = iter(this.#waiters);
     for (const waiter of take(it, n)) {
       waiter.resolve();

notify_test.ts

@@ -1,5 +1,5 @@
 import { delay } from "@std/async/delay";
-import { assertEquals, assertRejects } from "@std/assert";
+import { assertEquals, assertRejects, assertThrows } from "@std/assert";
 import { promiseState } from "./promise_state.ts";
 import { Notify } from "./notify.ts";
 
@@ -109,4 +109,17 @@ Deno.test("Notify", async (t) => {
       );
     },
   );
+
+  await t.step(
+    "'notify' throws RangeError if size is not a positive safe integer",
+    () => {
+      const notify = new Notify();
+      assertThrows(() => notify.notify(NaN), RangeError);
+      assertThrows(() => notify.notify(Infinity), RangeError);
+      assertThrows(() => notify.notify(-Infinity), RangeError);
+      assertThrows(() => notify.notify(-1), RangeError);
+      assertThrows(() => notify.notify(1.1), RangeError);
+      assertThrows(() => notify.notify(0), RangeError);
+    },
+  );
 });