isAsyncIterable

Checks whether a value is asynchronously iterable. A value is async iterable if it is not null or undefined and has a callable [Symbol.asyncIterator] method. This matches the behavior of await and other async iteration constructs.

Signature

function isAsyncIterable<T = unknown>(value: unknown): value is AsyncIterable<T>

Parameters

Name	Data type	Description
value	unknown	The value to check. Must implement the async iterable protocol to return true.

Returns

A boolean:

• true: If the value is async iterable.
• false: Otherwise.

Examples

async function* gen() { yield 1 }
isAsyncIterable(gen())          // true

isAsyncIterable([])             // false
isAsyncIterable('abc')          // false
isAsyncIterable(null)           // false

Notes

• This helper checks only for the presence of a callable [Symbol.asyncIterator] method.
• It does not attempt to call the async iterator.
• Sync iterables are not considered async iterables.
• Use validateAsyncIterable if you need a Result<T> instead of a boolean.

Next up

isIterable