Add support for Brotli encoding (#15)

Fixes #12

index.js

@@ -5,16 +5,22 @@ const mimicResponse = require('mimic-response');
 
 module.exports = response => {
 	// TODO: Use Array#includes when targeting Node.js 6
-	if (['gzip', 'deflate'].indexOf(response.headers['content-encoding']) === -1) {
+	if (['gzip', 'deflate', 'br'].indexOf(response.headers['content-encoding']) === -1) {
 		return response;
 	}
 
-	const unzip = zlib.createUnzip();
+	const isBrotli = response.headers['content-encoding'] === 'br';
+
+	if (isBrotli && typeof zlib.createBrotliDecompress !== 'function') {
+		return response;
+	}
+
+	const decompress = isBrotli ? zlib.createBrotliDecompress() : zlib.createUnzip();
 	const stream = new PassThrough();
 
 	mimicResponse(response, stream);
 
-	unzip.on('error', err => {
+	decompress.on('error', err => {
 		// Ignore empty response
 		if (err.code === 'Z_BUF_ERROR') {
 			stream.end();
@@ -24,7 +30,7 @@ module.exports = response => {
 		stream.emit('error', err);
 	});
 
-	response.pipe(unzip).pipe(stream);
+	response.pipe(decompress).pipe(stream);
 
 	return stream;
 };

readme.md

@@ -2,7 +2,7 @@
 
 > Decompress a HTTP response if needed
 
-Decompresses the [response](https://nodejs.org/api/http.html#http_class_http_incomingmessage) from [`http.request`](https://nodejs.org/api/http.html#http_http_request_options_callback) if it's gzipped or deflated, otherwise just passes it through.
+Decompresses the [response](https://nodejs.org/api/http.html#http_class_http_incomingmessage) from [`http.request`](https://nodejs.org/api/http.html#http_http_request_options_callback) if it's gzipped, deflated or compressed with Brotli, otherwise just passes it through.
 
 Used by [`got`](https://github.com/sindresorhus/got).
 

test/test.js

@@ -29,6 +29,13 @@ test.before('setup', async () => {
 		res.end(await zlibP.deflate(fixture));
 	});
 
+	s.on('/brotli', async (req, res) => {
+		res.statusCode = 200;
+		res.setHeader('content-type', 'text/plain');
+		res.setHeader('content-encoding', 'br');
+		res.end(await zlibP.brotliCompress(fixture));
+	});
+
 	s.on('/missing-data', async (req, res) => {
 		res.statusCode = 200;
 		res.setHeader('content-encoding-type', 'text/plain');
@@ -75,6 +82,19 @@ test('decompress deflated content', async t => {
 	t.is(await getStream(res), fixture);
 });
 
+if (typeof zlib.brotliCompress === 'function') {
+	test('decompress brotli content', async t => {
+		const res = m(await httpGetP(`${s.url}/brotli`));
+
+		t.is(typeof res.httpVersion, 'string');
+		t.truthy(res.headers);
+
+		res.setEncoding('utf8');
+
+		t.is(await getStream(res), fixture);
+	});
+}
+
 test('ignore missing data', async t => {
 	const res = m(await httpGetP(`${s.url}/missing-data`));