Deno KV: Limitation of backoffSchedule and confusing error message

[kitsonk]

Version: Deno 2.1.4

Deno has a limit of a backoff schedule of 5 or less intervals. This limit is not documented and the error is uniformative and requires reading the code to actually determine the limit.

For example the following code:

const db = await Deno.open();
await db.enqueue("test", {
  backoffSchedule: [1000, 2000, 4000, 8000, 16000, 32000]
});

Will produce the following error, giving the user no indication of what the problem is:

TypeError: Invalid backoffSchedule
    await db.enqueue("test", {
             ^
    at validateBackoffSchedule (ext:deno_kv/01_db.ts:29:11)
    at Kv.enqueue (ext:deno_kv/01_db.ts:161:7)
    at Router.enqueue (file:///Users/kitsonk/github/herd/mod.ts:285:21)
    at test.ts:1:10

Also, the limitation of 5 intervals makes it difficult to implement a standard 32 or 64 second exponential backoff (as it would require 6 or 7 intervals). It maybe worth considering catering to allow a common pattern of backoff.