Fix hanging promise on timeout on HTTP error

Fixes #1341

source/as-promise/index.ts

@@ -148,9 +148,7 @@ export default function asPromise<T>(options: NormalizedOptions): CancelableRequ
 				resolve(options.resolveBodyOnly ? response.body as T : response as unknown as T);
 			};
 
-			request.once('response', onResponse);
-
-			request.once('error', async (error: RequestError) => {
+			const onError = async (error: RequestError) => {
 				if (promise.isCanceled) {
 					return;
 				}
@@ -219,14 +217,22 @@ export default function asPromise<T>(options: NormalizedOptions): CancelableRequ
 				if (error instanceof HTTPError) {
 					// The error will be handled by the `response` event
 					onResponse(request._response as Response);
+
+					// Reattach the error handler, because there may be a timeout later.
+					process.nextTick(() => {
+						request.once('error', onError);
+					});
 					return;
 				}
 
 				// Don't emit the `response` event
 				request.destroy();
 
 				reject(error);
-			});
+			};
+
+			request.once('response', onResponse);
+			request.once('error', onError);
 
 			proxyEvents(request, emitter, proxiedRequestEvents);
 		};

test/error.ts

@@ -2,7 +2,7 @@ import {promisify} from 'util';
 import http = require('http');
 import stream = require('stream');
 import test from 'ava';
-import got, {RequestError, HTTPError} from '../source';
+import got, {RequestError, HTTPError, TimeoutError} from '../source';
 import withServer from './helpers/with-server';
 
 const pStreamPipeline = promisify(stream.pipeline);
@@ -204,6 +204,19 @@ test('errors can have request property', withServer, async (t, server, got) => {
 	t.truthy(error.request.downloadProgress);
 });
 
+test('promise does not hang on timeout on HTTP error', withServer, async (t, server, got) => {
+	server.get('/', (_request, response) => {
+		response.statusCode = 404;
+		response.write('asdf');
+	});
+
+	await t.throwsAsync(got({
+		timeout: 100
+	}), {
+		instanceOf: TimeoutError
+	});
+});
+
 // Fails randomly on Node 10:
 // Blocked by https://github.com/istanbuljs/nyc/issues/619
 // eslint-disable-next-line ava/no-skip-test