/// <reference types="node" />
/// <reference types="node" />
import { Transform } from 'stream';
import type * as stream from 'stream';
declare type GetPropValue<T, K extends PropertyKey> = K extends (keyof T) ? T[K] : undefined;
declare type IfNeverThenUnknown<T> = [T] extends [never] ? unknown : T;
/**
 * If the `objectMode` and `writableObjectMode` options is not `true`,
 * the chunk value is always an instance of Buffer.
 */
export declare type InputChunkType<T extends stream.TransformOptions> = (true extends GetPropValue<T, 'objectMode' | 'writableObjectMode'> ? unknown : Buffer);
/**
 * If the `objectMode` and `readableObjectMode` options is not `true`,
 * the chunk value must be of type string or an instance of Buffer or Uint8Array.
 * @see https://github.com/nodejs/node/blob/v12.17.0/lib/_stream_readable.js#L226-L244
 */
export declare type OutputChunkType<T extends stream.TransformOptions> = IfNeverThenUnknown<T extends ({
    objectMode: true;
} | {
    readableObjectMode: true;
}) ? never : string | Buffer | Uint8Array>;
export declare type SourceIterator<TOpts extends stream.TransformOptions> = (AsyncIterableIterator<{
    chunk: InputChunkType<TOpts>;
    encoding: BufferEncoding;
}>);
export declare type TransformFunction<TOpts extends stream.TransformOptions> = ((source: SourceIterator<TOpts>) => Iterable<OutputChunkType<TOpts>> | AsyncIterable<OutputChunkType<TOpts>>);
export declare class TransformFromAsyncIterable<TOpts extends stream.TransformOptions = Record<string, never>> extends Transform {
    private transformCallback;
    private isFinished;
    private receiveData?;
    private readonly receivedDataList;
    constructor(transformFn: TransformFunction<TOpts>, opts?: TOpts);
    _transform(chunk: InputChunkType<TOpts>, encoding: BufferEncoding, callback: stream.TransformCallback): void;
    _flush(callback: stream.TransformCallback): void;
    private finish;
    private callTransformCallback;
    private createSource;
    private emitToSource;
    private emitFinishEventAfterCallback;
}
export declare function transformFrom<TOpts extends stream.TransformOptions = Record<string, never>>(transformFn: TransformFunction<TOpts>, options?: TOpts): stream.Transform;
export {};