ReadableBase.prototype.map - node__stream.d.ts - Node

method ReadableBase.prototype.map

Usage in Deno

```typescript import { ReadableBase } from "node:node__stream.d.ts"; ```



ReadableBase.prototype.map(fn: (data: any,
options?: Pick<ArrayOptions, "signal">,
) => any,
options?: ArrayOptions,
): Readable

This method allows mapping over the stream. The *fn* function will be called for every chunk in the stream. If the *fn* function returns a promise - that promise will be `await`ed before being passed to the result stream.

Parameters



fn: (data: any,
options?: Pick<ArrayOptions, "signal">,
) => any

a function to map over every chunk in the stream. Async or not.

optional



options: ArrayOptions

Return Type

Readable

a stream mapped with the function *fn*.