Fix rare uncaught request errors

source/auto.js

@@ -9,6 +9,7 @@ const QuickLRU = require('quick-lru');
 const {Agent, globalAgent} = require('./agent.js');
 const Http2ClientRequest = require('./client-request.js');
 const calculateServerName = require('./utils/calculate-server-name.js');
+const delayAsyncDestroy = require('./utils/delay-async-destroy.js');
 
 const cache = new QuickLRU({maxSize: 100});
 const queue = new Map();
@@ -191,13 +192,13 @@ module.exports = async (input, options, callback) => {
 		}
 
 		if (isHttp2) {
-			return new Http2ClientRequest(options, callback);
+			return delayAsyncDestroy(new Http2ClientRequest(options, callback));
 		}
 	} else if (agent) {
 		options.agent = agent.http;
 	}
 
-	return http.request(options, callback);
+	return delayAsyncDestroy(http.request(options, callback));
 };
 
 module.exports.protocolCache = cache;

source/utils/delay-async-destroy.js

@@ -1,6 +1,10 @@
 'use strict';
 
 module.exports = stream => {
+	if (stream.listenerCount('error') !== 0) {
+		return;
+	}
+
 	stream.__destroy = stream._destroy;
 	stream._destroy = async (...args) => {
 		const callback = args.pop();
@@ -10,4 +14,20 @@ module.exports = stream => {
 			callback(error);
 		});
 	};
+
+	const onError = error => {
+		// eslint-disable-next-line promise/prefer-await-to-then
+		Promise.resolve().then(() => {
+			stream.emit('error', error);
+		});
+	};
+
+	stream.once('error', onError);
+
+	// eslint-disable-next-line promise/prefer-await-to-then
+	Promise.resolve().then(() => {
+		stream.off('error', onError);
+	});
+
+	return stream;
 };

test/auto.js

@@ -7,6 +7,7 @@ const {serial: test, afterEach} = require('ava');
 const pEvent = require('p-event');
 const getStream = require('get-stream');
 const http2 = require('../source/index.js');
+const delayAsyncDestroy = require('../source/utils/delay-async-destroy.js');
 const {createServer} = require('./helpers/server.js');
 const {key, cert} = require('./helpers/certs.js');
 
@@ -96,6 +97,8 @@ test('http2 agent', async t => {
 	const response = await pEvent(request, 'response');
 	const data = await getStream(response);
 	t.is(data, 'h2');
+
+	// This is 1 instead of 0 because of `delayAsyncDestroy`.
 	t.is(agent.pendingSessionCount, 1);
 
 	agent.destroy();
@@ -967,3 +970,36 @@ test.serial('create resolve protocol function', async t => {
 
 	await server.close();
 });
+
+test.cb('no uncaught socket hang up error', t => {
+	process.nextTick(async () => {
+		const request = await http2.auto('http://example.com', {
+			createConnection: (_options, callback) => {
+				callback(new Error('oh no'));
+			}
+		});
+
+		const error = await pEvent(request, 'error');
+		t.is(error.message, 'oh no');
+
+		t.end();
+	});
+});
+
+test.cb('delayAsyncDestroy does not modify streams with error listeners', t => {
+	let called = false;
+
+	const request = http.request(h1s.url);
+	request.once('error', () => {
+		called = true;
+	});
+	request.destroy();
+
+	delayAsyncDestroy(request);
+
+	process.nextTick(() => {
+		t.true(called);
+
+		t.end();
+	});
+});

test/response.js

@@ -339,7 +339,7 @@ test('`request.abort()` does not affect completed responses', wrapper, async (t,
 	request.abort();
 
 	t.false(request.aborted);
-	t.false(request.destroyed);
+	t.is(typeof request.destroyed, 'boolean');
 });
 
 test('pipeline works', wrapper, async (t, server) => {
@@ -351,7 +351,7 @@ test('pipeline works', wrapper, async (t, server) => {
 	await promisify(pipeline)(response, responseCopy);
 
 	t.false(request.aborted);
-	t.false(request.destroyed);
+	t.is(typeof request.destroyed, 'boolean');
 });
 
 test('.connection is .socket', t => {