expresspayments/esm/net/FetchHttpClient.js

ExpressPayments API wrapper

import { HttpClient, HttpClientResponse, } from './HttpClient.js';
/**
 * HTTP client which uses a `fetch` function to issue requests.
 *
 * By default, relies on the global `fetch` function, but an optional function
 * can be passed in. If passing in a function, it is expected to match the Web
 * Fetch API. As an example, this could be the function provided by the
 * node-fetch package (https://github.com/node-fetch/node-fetch).
 */
export class FetchHttpClient extends HttpClient {
    constructor(fetchFn) {
        super();
        this._fetchFn = fetchFn;
    }
    /** @override. */
    getClientName() {
        return 'fetch';
    }
    makeRequest(host, port, path, method, headers, requestData, protocol, timeout) {
        const isInsecureConnection = protocol === 'http';
        const url = new URL(path, `${isInsecureConnection ? 'http' : 'https'}://${host}`);
        url.port = port;
        // For methods which expect payloads, we should always pass a body value
        // even when it is empty. Without this, some JS runtimes (e.g. Deno) will
        // inject a second Content-Length header. See https://github.com/expresspayments/expresspayments-node/issues/1519
        // for more details.
        const methodHasPayload = method == 'POST' || method == 'PUT' || method == 'PATCH';
        const body = requestData || (methodHasPayload ? '' : undefined);
        const fetchFn = this._fetchFn || fetch;
        const fetchPromise = fetchFn(url.toString(), {
            method,
            // @ts-ignore
            headers,
            // @ts-ignore
            body,
        });
        // The Fetch API does not support passing in a timeout natively, so a
        // timeout promise is constructed to race against the fetch and preempt the
        // request, simulating a timeout.
        //
        // This timeout behavior differs from Node:
        // - Fetch uses a single timeout for the entire length of the request.
        // - Node is more fine-grained and resets the timeout after each stage of
        //   the request.
        //
        // As an example, if the timeout is set to 30s and the connection takes 20s
        // to be established followed by 20s for the body, Fetch would time out but
        // Node would not. The more fine-grained timeout cannot be implemented with
        // fetch.
        let pendingTimeoutId;
        const timeoutPromise = new Promise((_, reject) => {
            pendingTimeoutId = setTimeout(() => {
                pendingTimeoutId = null;
                reject(HttpClient.makeTimeoutError());
            }, timeout);
        });
        return Promise.race([fetchPromise, timeoutPromise])
            .then((res) => {
            return new FetchHttpClientResponse(res);
        })
            .finally(() => {
            if (pendingTimeoutId) {
                clearTimeout(pendingTimeoutId);
            }
        });
    }
}
export class FetchHttpClientResponse extends HttpClientResponse {
    constructor(res) {
        super(res.status, FetchHttpClientResponse._transformHeadersToObject(res.headers));
        this._res = res;
    }
    getRawResponse() {
        return this._res;
    }
    toStream(streamCompleteCallback) {
        // Unfortunately `fetch` does not have event handlers for when the stream is
        // completely read. We therefore invoke the streamCompleteCallback right
        // away. This callback emits a response event with metadata and completes
        // metrics, so it's OK to do this without waiting for the stream to be
        // completely read.
        streamCompleteCallback();
        // Fetch's `body` property is expected to be a readable stream of the body.
        return this._res.body;
    }
    toJSON() {
        return this._res.json();
    }
    static _transformHeadersToObject(headers) {
        // Fetch uses a Headers instance so this must be converted to a barebones
        // JS object to meet the HttpClient interface.
        const headersObj = {};
        for (const entry of headers) {
            if (!Array.isArray(entry) || entry.length != 2) {
                throw new Error('Response objects produced by the fetch function given to FetchHttpClient do not have an iterable headers map. Response#headers should be an iterable object.');
            }
            headersObj[entry[0]] = entry[1];
        }
        return headersObj;
    }
}