Don't throw HTTPError on 304 responses (#252)

index.js

@@ -119,7 +119,7 @@ function asPromise(opts) {
 						}
 					}
 
-					if (statusCode < 200 || statusCode > limitStatusCode) {
+					if (statusCode !== 304 && (statusCode < 200 || statusCode > limitStatusCode)) {
 						throw new got.HTTPError(statusCode, opts);
 					}
 
@@ -178,7 +178,7 @@ function asStream(opts) {
 
 		res.pipe(output);
 
-		if (statusCode < 200 || statusCode > 299) {
+		if (statusCode !== 304 && (statusCode < 200 || statusCode > 299)) {
 			proxy.emit('error', new got.HTTPError(statusCode, opts), null, res);
 			return;
 		}

readme.md

@@ -340,7 +340,9 @@ request(`https://${config.host}/production/`, {
 ```
 
 
-## Tip
+## Tips
+
+### User Agent
 
 It's a good idea to set the `'user-agent'` header so the provider can more easily see how their resource is used. By default, it's the URL to this repo.
 
@@ -355,6 +357,10 @@ got('todomvc.com', {
 });
 ```
 
+### 304 Responses
+
+Bear in mind, if you send an `if-modified-since` header and receive a `304 Not Modified` response, the body will be empty. It's your responsibility to cache and retrieve the body contents.
+
 
 ## Related
 

test/http.js

@@ -15,6 +15,11 @@ test.before('setup', async () => {
 		res.end();
 	});
 
+	s.on('/304', (req, res) => {
+		res.statusCode = 304;
+		res.end();
+	});
+
 	s.on('/404', (req, res) => {
 		res.statusCode = 404;
 		res.end('not');
@@ -54,6 +59,14 @@ test('error with code', async t => {
 	}
 });
 
+test('status code 304 doesn\'t throw', async t => {
+	const p = got(`${s.url}/304`);
+	await t.notThrows(p);
+	const response = await p;
+	t.is(response.statusCode, 304);
+	t.is(response.body, '');
+});
+
 test('buffer on encoding === null', async t => {
 	const data = (await got(s.url, {encoding: null})).body;
 	t.truthy(Buffer.isBuffer(data));