102 lines
4.3 KiB
JavaScript
102 lines
4.3 KiB
JavaScript
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 (eg. Deno) will
|
|
// inject a second Content-Length header. See https://github.com/stripe/stripe-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 timeout 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;
|
|
}
|
|
}
|