Add exponential retry on network errors

Closes #98

index.js

@@ -19,11 +19,17 @@ var nodeStatusCodes = require('node-status-codes');
 var isPlainObj = require('is-plain-obj');
 var parseJson = require('parse-json');
 
+function backoff(iter) {
+	var noise = Math.random() * 1000;
+	return (1 << iter) * 1000 + noise;
+}
+
 function requestAsEventEmitter(opts) {
 	opts = opts || {};
 
 	var ee = new EventEmitter();
 	var redirectCount = 0;
+	var retryCount = 0;
 
 	var get = function (opts) {
 		var fn = opts.protocol === 'https:' ? https : http;
@@ -49,6 +55,11 @@ function requestAsEventEmitter(opts) {
 
 			ee.emit('response', typeof unzipResponse === 'function' ? unzipResponse(res) : res);
 		}).once('error', function (err) {
+			if (retryCount < opts.retries) {
+				setTimeout(get, backoff(retryCount++), opts);
+				return;
+			}
+
 			ee.emit('error', new got.RequestError(err, opts));
 		});
 
@@ -194,6 +205,7 @@ function normalizeArguments(url, opts) {
 	opts = objectAssign(
 		{protocol: 'http:', path: ''},
 		url,
+		{retries: 5},
 		opts
 	);
 

readme.md

@@ -12,7 +12,7 @@
 
 A nicer interface to the built-in [`http`](http://nodejs.org/api/http.html) module.
 
-It supports following redirects, promises, streams, automagically handling gzip/deflate and some convenience options.
+It supports following redirects, promises, streams, retries, automagically handling gzip/deflate and some convenience options.
 
 Created because [`request`](https://github.com/mikeal/request) is bloated *(several megabytes!)*.
 
@@ -111,6 +111,14 @@ Type: `number`
 
 Milliseconds after which the request will be aborted and an error event with `ETIMEDOUT` code will be emitted.
 
+###### retries
+
+Type: `number`  
+Default: `5`
+
+Number of request retries when network errors happens.
+
+
 ##### callback(error, data, response)
 
 Function to be called when error or data are received. If omitted, a promise will be returned.

test/http.js

@@ -69,7 +69,7 @@ test('http - buffer on encoding === null', t => {
 });
 
 test('http - timeout option', t => {
-	got(`${s.url}/404`, {timeout: 1}, err => {
+	got(`${s.url}/404`, {timeout: 1, retries: 1}, err => {
 		t.is(err.code, 'ETIMEDOUT');
 		t.end();
 	});

test/retry.js

@@ -0,0 +1,31 @@
+import test from 'ava';
+import got from '../';
+import {createServer} from './_server';
+
+const s = createServer();
+
+s.on('/long', () => {});
+
+let knocks = 0;
+s.on('/knock-twice', (req, res) => {
+	if (knocks++ === 1) {
+		res.end('who`s there?');
+	}
+});
+
+test.before('retry - setup', t => {
+	s.listen(s.port, () => t.end());
+});
+
+test('retry - timeout errors', t => {
+	got(`${s.url}/knock-twice`, {timeout: 1000}, (err, data) => {
+		t.ifError(err);
+		t.is(data, 'who`s there?');
+		t.end();
+	});
+});
+
+test.after('error - cleanup', t => {
+	s.close();
+	t.end();
+});