What types does the main pLimit function expect for its concurrency argument?

The pLimit function accepts two types for its concurrency argument:

1. number — A direct concurrency limit value (minimum: 1)
2. object — An options object with a concurrency property and optional rejectOnClear boolean

According to [index.d.ts:L89], the function signature is:

export default function pLimit(concurrency: number | Options): LimitFunction;

Where the Options type [index.d.ts:L91-L109] defines:

• concurrency (required): number — minimum 1
• rejectOnClear (optional): boolean — defaults to false

In the implementation [index.js:L3-L10], the function handles both cases by checking if the argument is an object and destructuring accordingly:

if (typeof concurrency === 'object') {
	({concurrency, rejectOnClear = false} = concurrency);
}

So you can pass either pLimit(1) for a simple concurrency limit, or pLimit({concurrency: 1, rejectOnClear: true}) for more control over behavior.

FOLLOW_UPS:

• How does the validation work for concurrency values?
• What happens when rejectOnClear is enabled?
• How do activeCount and pendingCount differ?