Drop fetch-ponyfill in favor of native fetch

Change-type: minor

lib/progress.ts

@@ -94,17 +94,10 @@ export interface BalenaRequestPassThroughStream extends Stream.PassThrough {
  * 		stream.on 'progress', (state) ->
  * 			console.log(state)
  */
-export function estimate(
-	requestAsync?: ReturnType<typeof getRequestAsync>,
-	isBrowser?: boolean,
-) {
+export function estimate(requestAsync: ReturnType<typeof getRequestAsync>) {
 	return async function (
 		options: BalenaRequestOptions,
 	): Promise<BalenaRequestPassThroughStream> {
-		if (requestAsync == null) {
-			requestAsync = utils.getRequestAsync();
-		}
-
 		options.gzip = false;
 		options.headers!['Accept-Encoding'] = 'gzip, deflate';
 
@@ -155,51 +148,7 @@ export function estimate(
 			output.emit('progress', state),
 		);
 
-		if (!isBrowser && utils.isResponseCompressed(response)) {
-			// eslint-disable-next-line @typescript-eslint/no-var-requires
-			const zlib = require('zlib') as typeof import('zlib');
-
-			// Be more lenient with decoding compressed responses, since (very rarely)
-			// servers send slightly invalid gzip responses that are still accepted
-			// by common browsers.
-			// Always using Z_SYNC_FLUSH is what cURL does.
-			let zlibOptions = {
-				flush: zlib.constants.Z_SYNC_FLUSH,
-				finishFlush: zlib.constants.Z_SYNC_FLUSH,
-			};
-
-			// Allow overriding this behaviour by setting the ZLIB_FLUSH env var
-			// to one of the allowed zlib flush values (process.env.ZLIB_FLUSH="Z_NO_FLUSH").
-			// https://github.com/nodejs/node/blob/master/doc/api/zlib.md#zlib-constants
-			if (process.env.ZLIB_FLUSH && process.env.ZLIB_FLUSH in zlib.constants) {
-				zlibOptions = {
-					flush:
-						zlib.constants[
-							process.env.ZLIB_FLUSH as keyof typeof zlib.constants
-						],
-					finishFlush:
-						zlib.constants[
-							process.env.ZLIB_FLUSH as keyof typeof zlib.constants
-						],
-				};
-			}
-
-			const gunzip = zlib.createGunzip(zlibOptions);
-			gunzip.on('error', (e) => output.emit('error', e));
-
-			// Uncompress after or before piping through progress
-			// depending on the response length available to us
-			if (
-				responseLength.compressed != null &&
-				responseLength.uncompressed == null
-			) {
-				responseStream.pipe(progressStream).pipe(gunzip).pipe(output);
-			} else {
-				responseStream.pipe(gunzip).pipe(progressStream).pipe(output);
-			}
-		} else {
-			responseStream.pipe(progressStream).pipe(output);
-		}
+		responseStream.pipe(progressStream).pipe(output);
 
 		// Stream any request errors on downstream
 		responseStream.on('error', (e: Error) => output.emit('error', e));

lib/request.ts

@@ -351,10 +351,7 @@ export function getRequest({
 		return prepareOptions(options)
 			.then(interceptRequestOptions, interceptRequestError)
 			.then(async (opts) => {
-				const download = await progress.estimate(
-					requestStream,
-					isBrowser,
-				)(opts);
+				const download = await progress.estimate(requestStream)(opts);
 
 				if (!utils.isErrorCode(download.response.statusCode)) {
 					// TODO: Move this to balena-image-manager

lib/utils.ts

@@ -13,11 +13,6 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */
-
-const { fetch: normalFetch, Headers: HeadersPonyfill } =
-	// eslint-disable-next-line @typescript-eslint/no-var-requires
-	(require('fetch-ponyfill') as typeof import('fetch-ponyfill'))({ Promise });
-
 import * as urlLib from 'url';
 import * as qs from 'qs';
 import * as errors from 'balena-errors';
@@ -31,6 +26,8 @@ import type {
 } from './request';
 import { Readable } from 'stream';
 
+const nativeFetch = fetch;
+
 const IS_BROWSER = typeof window !== 'undefined' && window !== null;
 
 /**
@@ -311,7 +308,7 @@ const processRequestOptions = function (options: BalenaRequestOptions) {
 		compress: options.gzip,
 		signal: options.signal,
 		body,
-		headers: new HeadersPonyfill(headers),
+		headers: new Headers(headers),
 		mode: 'cors',
 		redirect: options.followRedirect === false ? 'manual' : 'follow',
 	};
@@ -399,7 +396,7 @@ const getForm = (): FormDataNodeType | FormData => {
 
 // This is the actual implementation that hides the internal `retriesRemaining` parameter
 async function requestAsync(
-	fetch: typeof normalFetch,
+	$fetch: typeof nativeFetch,
 	options: BalenaRequestOptions,
 	retriesRemaining?: number,
 ): Promise<BalenaRequestResponse> {
@@ -409,7 +406,7 @@ async function requestAsync(
 	}
 
 	// When streaming, prefer using the native Headers object if available
-	if (fetch !== normalFetch && typeof Headers === 'function') {
+	if ($fetch !== nativeFetch && typeof Headers === 'function') {
 		// Edge's Headers(args) ctor doesn't work as expected when passed in a headers object
 		// from fetch-ponyfill, treating it as a plain object instead of using the iterator symbol.
 		// As a result when fetch-readablestream uses the native fetch on Edge, the headers sent
@@ -451,6 +448,15 @@ async function requestAsync(
 
 			const encoder = new FormDataEncoder(form as FormDataNodeType);
 			opts.headers.set('Content-Type', encoder.headers['Content-Type']);
+			// future proofing in case the user has already defined this
+			if (!('duplex' in opts)) {
+				// The spec requires setting this when uploading files.
+				// See: https://fetch.spec.whatwg.org/#enumdef-requestduplex
+				// @ts-expect-error The RequestInit type in @types/node/global.d.ts does include
+				// the duplex property, but lib.dom.d.ts does not, so since this lib needs to run
+				// on both node & browsers, the types used need to satisfy both.
+				opts.duplex = 'half';
+			}
 			const length = encoder.headers['Content-Length'];
 			if (length != null) {
 				opts.headers.set('Content-Length', length);
@@ -462,8 +468,8 @@ async function requestAsync(
 
 	try {
 		const requestTime = Date.now();
-		let p = fetch(url, opts);
-		if (opts.timeout && IS_BROWSER) {
+		let p = $fetch(url, opts);
+		if (opts.timeout) {
 			p = new Promise((resolve, reject) => {
 				setTimeout(() => {
 					reject(new Error('network timeout'));
@@ -488,7 +494,7 @@ async function requestAsync(
 		return response;
 	} catch (err) {
 		if (retriesRemaining > 0) {
-			return await requestAsync(fetch, options, retriesRemaining - 1);
+			return await requestAsync($fetch, options, retriesRemaining - 1);
 		}
 		throw err;
 	}
@@ -531,7 +537,7 @@ function handleAbortIfNotSupported(
  * @function
  * @protected
  *
- * @param {Function} [fetch] - the fetch implementation, defaults to that returned by `fetch-ponyfill`.
+ * @param {Function} [$fetch] - the fetch implementation, defaults to native node/browser fetch.
  *
  * @description The returned function keeps partial compatibility with promisified `request`
  * but uses `fetch` behind the scenes.
@@ -541,7 +547,7 @@ function handleAbortIfNotSupported(
  * utils.getRequestAsync()({ url: 'http://example.com' }).then (response) ->
  * 	console.log(response)
  */
-export function getRequestAsync($fetch: typeof fetch = normalFetch) {
+export function getRequestAsync($fetch = nativeFetch) {
 	return (options: BalenaRequestOptions) => requestAsync($fetch, options);
 }
 

package.json

@@ -69,7 +69,6 @@
   "dependencies": {
     "@balena/node-web-streams": "^0.2.3",
     "balena-errors": "^4.9.0",
-    "fetch-ponyfill": "^7.1.0",
     "fetch-readablestream": "^0.2.0",
     "form-data-encoder": "1.7.2",
     "formdata-node": "^4.0.0",

tests/utils.spec.ts

@@ -1,13 +1,11 @@
 import { expect } from 'chai';
 import { TokenType } from 'balena-auth/build/token';
 import setup from './setup';
-import * as fetchPonyfill from 'fetch-ponyfill';
 import * as sinon from 'sinon';
 import * as tokens from './tokens.json';
 import * as utils from '../build/utils';
 import type { BalenaRequestResponse } from '../build/request';
 
-const { Headers } = fetchPonyfill({ Promise });
 const { auth } = setup();
 const johnDoeFixture = tokens.johndoe;