Is there a way to inspect the pending queue size?

Question

RepoPilot · Accepted Answer

Yes, there is. You can inspect the pending queue size using the **`pendingCount`** property on the limit function.

According to the TypeScript definitions [index.d.ts:L8-L10], `pendingCount` is a read-only property that represents:

> "The number of promises that are waiting to run (i.e. their internal `fn` was not called yet)."

Here's a practical example from the test suite [test.js:L180-L190]:

```javascript
const limit = pLimit(1);

Array.from({length: 1}, () => limit(() => delay(1000)));
Array.from({length: 3}, () => limit(() => delay(1000)));

await Promise.resolve();
t.is(limit.pendingCount, 3);  // Check the pending count
limit.clearQueue();
t.is(limit.pendingCount, 0);
```

This is useful for monitoring how many tasks are queued and waiting to execute. The library also provides `activeCount` [index.d.ts:L4-L6] if you need to know how many promises are currently running.

FOLLOW_UPS:
- What does activeCount tell you about running tasks?
- How can you dynamically change the concurrency limit?
- What happens when you call clearQueue with rejectOnClear enabled?