alcaeus/helpers/fetchToStream.js

Hydra Core hypermedia-aware client library

import buffer from 'buffer';
import stream from 'readable-stream';
// from https://github.com/bergos/nodeify-fetch/blob/master/lib/WhatwgReadable.js
class WhatwgReadable extends stream.Readable {
    constructor(body) {
        let reader;
        function getReader() {
            if (!reader) {
                reader = body.getReader();
            }
            return reader;
        }
        super({
            read: () => {
                getReader().read().then((chunk) => {
                    if (chunk.done) {
                        this.push(null);
                    }
                    else {
                        this.push(buffer.Buffer.from(chunk.value));
                    }
                }).catch((err) => {
                    this.emit('error', err);
                });
            },
        });
    }
}
class ArrayBufferReadable extends stream.Readable {
    constructor(callback) {
        let done = false;
        super({
            read: () => {
                if (done) {
                    return;
                }
                done = true;
                callback().then((arrayBuffer) => {
                    this.push(buffer.Buffer.from(arrayBuffer));
                    this.push(null);
                });
            },
        });
    }
}
export function patchResponseBody(body) {
    if (body.body && 'readable' in body.body) {
        return body.body;
    }
    if (body.body && 'getReader' in body.body) {
        return new WhatwgReadable(body.body);
    }
    return new ArrayBufferReadable(() => {
        return body.arrayBuffer();
    });
}