API · Consume

each()

Start a stream and run a synchronous side-effect callback for every successful value.

Signature

each(fn: (value: T, context: C) => void): void

Example

stream.each((value) => console.log(value))

Behavior

each() attaches and resumes a terminal consumer immediately. The callback runs in input order. Context is supplied only when the callback declares a second parameter, and is materialized when needed. The method returns undefined and offers no completion promise.

The callback is synchronous: returned promises are ignored and do not apply backpressure. Use mapAsync(...).drain() for awaited side effects. Record errors are emitted on the end-of-chain 'error' event; without a listener they can escape as uncaught failures. Prefer drain() or toAsyncIterator() when structured completion/error handling matters.

Related

tap(), drain(), toArray(), pull()