@whatwg-node/node-fetch/esm/fetchUndici.js

Fetch API implementation for Node

import { PassThrough, Readable } from 'node:stream';
import { isUint8Array } from 'node:util/types';
import { createBrotliDecompress, createGunzip, createInflate, createInflateRaw } from 'node:zlib';
import { fetchNodeHttp } from './fetchNodeHttp.js';
import { PonyfillRequest } from './Request.js';
import { PonyfillResponse } from './Response.js';
import { PonyfillURL } from './URL.js';
import { createDeferredPromise, getHeadersObj, isNodeReadable } from './utils.js';
export function createFetchUndici(getGlobalDispatcher) {
    return function fetchUndici(fetchRequest) {
        const dispatcher = fetchRequest.dispatcher || getGlobalDispatcher();
        if (!dispatcher) {
            if (process.env.DEBUG) {
                console.debug('[@whatwg-node/node-fetch] - native undici dispatcher not available, falling back to node:http');
            }
            return fetchNodeHttp(fetchRequest);
        }
        const deferred = createDeferredPromise();
        let abortListener;
        let passthrough;
        let response;
        let body = null;
        const bodyInit = fetchRequest['bodyInit'];
        if (bodyInit != null) {
            if (typeof bodyInit === 'string' ||
                Buffer.isBuffer(bodyInit) ||
                isUint8Array(bodyInit) ||
                bodyInit instanceof Readable) {
                body = bodyInit;
            }
            else if (fetchRequest.body != null) {
                if (isNodeReadable(fetchRequest.body?.readable)) {
                    body = fetchRequest.body.readable;
                }
                else {
                    body = Readable.from(fetchRequest.body);
                }
            }
        }
        function setPassthrough(contentEncoding) {
            switch (contentEncoding) {
                case 'x-gzip':
                case 'gzip':
                    passthrough = createGunzip();
                    break;
                case 'x-deflate':
                case 'deflate':
                    passthrough = createInflate();
                    break;
                case 'x-deflate-raw':
                case 'deflate-raw':
                    passthrough = createInflateRaw();
                    break;
                case 'br':
                    passthrough = createBrotliDecompress();
                    break;
                default:
                    passthrough = new PassThrough();
            }
            return passthrough;
        }
        function onAbort(e) {
            fetchRequest['_signal']?.removeEventListener('abort', abortListener);
            passthrough?.destroy(e);
            deferred.reject(e);
        }
        const headersSerializer = fetchRequest.headersSerializer || getHeadersObj;
        const nodeHeaders = headersSerializer(fetchRequest.headers);
        if (nodeHeaders['accept-encoding'] == null) {
            nodeHeaders['accept-encoding'] = 'gzip, deflate, br';
        }
        const dispatcherReturn = dispatcher.dispatch({
            origin: fetchRequest.parsedUrl.origin,
            path: fetchRequest.parsedUrl.pathname,
            query: Object.fromEntries(fetchRequest.parsedUrl.searchParams),
            method: fetchRequest.method,
            headers: nodeHeaders,
            body,
        }, {
            onRequestStart(controller) {
                abortListener = function abortListener() {
                    onAbort(fetchRequest['_signal']?.reason);
                    controller.abort(fetchRequest['_signal']?.reason);
                };
                fetchRequest['_signal']?.addEventListener('abort', abortListener, { once: true });
            },
            onRequestUpgrade(_controller, statusCode, headers, socket) {
                response = new PonyfillResponse(socket, {
                    status: statusCode,
                    headers: headers,
                    url: fetchRequest.url,
                });
                deferred.resolve(response);
                fetchRequest['_signal']?.removeEventListener('abort', abortListener);
            },
            onResponseStart(controller, statusCode, headers, statusMessage) {
                if (headers.location) {
                    if (fetchRequest.redirect === 'error') {
                        const redirectError = new Error('Redirects are not allowed');
                        deferred.reject(redirectError);
                        controller.resume();
                        return;
                    }
                    if (fetchRequest.redirect === 'follow') {
                        const redirectedUrl = new PonyfillURL(headers.location, fetchRequest.parsedUrl || fetchRequest.url);
                        const redirectResponse$ = fetchUndici(new PonyfillRequest(redirectedUrl, fetchRequest));
                        deferred.resolve(redirectResponse$.then(redirectResponse => {
                            redirectResponse.redirected = true;
                            return redirectResponse;
                        }));
                        controller.resume();
                        return;
                    }
                }
                passthrough = setPassthrough(headers['content-encoding']);
                deferred.resolve(new PonyfillResponse(passthrough, {
                    status: statusCode,
                    statusText: statusMessage,
                    headers: headers,
                    url: fetchRequest.url,
                }));
            },
            onResponseData(controller, chunk) {
                passthrough.write(chunk);
                if (controller.reason) {
                    onAbort(controller.reason);
                }
            },
            onResponseEnd(controller, _trailers) {
                if (controller.reason) {
                    onAbort(controller.reason);
                }
                else {
                    passthrough.end();
                    fetchRequest['_signal']?.removeEventListener('abort', abortListener);
                }
            },
            onResponseError(controller, error) {
                onAbort(error || controller.reason);
            },
            // Old Undici support
            onConnect(abort) {
                abortListener = function abortListener() {
                    abort(fetchRequest['_signal']?.reason);
                    onAbort(fetchRequest['_signal']?.reason);
                };
                fetchRequest['_signal']?.addEventListener('abort', abortListener, { once: true });
            },
            onError(error) {
                onAbort(error);
            },
            // TODO: onUpgrade
            onHeaders(statusCode, headersBuf, _resume, statusText) {
                const headers = headersBuf.map(headerBuf => {
                    const header = headerBuf
                        .toString('utf-8')
                        .split(/:\s(.+)/)
                        .slice(0, 2);
                    if (header[0] === 'content-encoding') {
                        const contentEncoding = header[1];
                        setPassthrough(contentEncoding);
                    }
                    return header;
                });
                passthrough ||= new PassThrough();
                deferred.resolve(new PonyfillResponse(passthrough, {
                    status: statusCode,
                    statusText,
                    headers,
                    url: fetchRequest.url,
                }));
                return true;
            },
            onData(chunk) {
                return passthrough.write(chunk);
            },
            onComplete() {
                passthrough.end();
                fetchRequest['_signal']?.removeEventListener('abort', abortListener);
            },
        });
        if (!dispatcherReturn) {
            console.warn('Undici dispatcher returned false');
        }
        return deferred.promise;
    };
}