Adding Brotli Support (#598)

* adding brotli support
* support old node versions
* better test

.gitignore

@@ -37,3 +37,6 @@ lib
 # Ignore package manager lock files
 package-lock.json
 yarn.lock
+
+# Ignore IDE
+.idea

src/index.js

@@ -244,6 +244,14 @@ export default function fetch(url, opts) {
 				return;
 			}
 
+			// for br
+			if (codings == 'br' && typeof zlib.createBrotliDecompress === 'function') {
+				body = body.pipe(zlib.createBrotliDecompress());
+				response = new Response(body, response_options);
+				resolve(response);
+				return;
+			}
+
 			// otherwise, use response as-is
 			response = new Response(body, response_options);
 			resolve(response);

test/server.js

@@ -94,6 +94,18 @@ export default class TestServer {
 			});
 		}
 
+		if (p === '/brotli') {
+			res.statusCode = 200;
+			res.setHeader('Content-Type', 'text/plain');
+			if (typeof zlib.createBrotliDecompress === 'function') {
+				res.setHeader('Content-Encoding', 'br');
+				zlib.brotliCompress('hello world', function (err, buffer) {
+					res.end(buffer);
+				});
+			}
+		}
+
+
 		if (p === '/deflate-raw') {
 			res.statusCode = 200;
 			res.setHeader('Content-Type', 'text/plain');
@@ -308,6 +320,12 @@ export default class TestServer {
 			res.end();
 		}
 
+		if (p === '/no-content/brotli') {
+			res.statusCode = 204;
+			res.setHeader('Content-Encoding', 'br');
+			res.end();
+		}
+
 		if (p === '/not-modified') {
 			res.statusCode = 304;
 			res.end();

test/test.js

@@ -50,6 +50,7 @@ import RequestOrig from '../src/request.js';
 import ResponseOrig from '../src/response.js';
 import Body from '../src/body.js';
 import Blob from '../src/blob.js';
+import zlib from "zlib";
 
 const supportToString = ({
 	[Symbol.toStringTag]: 'z'
@@ -664,6 +665,33 @@ describe('node-fetch', () => {
 		});
 	});
 
+	it('should decompress brotli response', function() {
+		if(typeof zlib.createBrotliDecompress !== 'function') this.skip();
+		const url = `${base}brotli`;
+		return fetch(url).then(res => {
+			expect(res.headers.get('content-type')).to.equal('text/plain');
+			return res.text().then(result => {
+				expect(result).to.be.a('string');
+				expect(result).to.equal('hello world');
+			});
+		});
+	});
+
+	it('should handle no content response with brotli encoding', function() {
+		if(typeof zlib.createBrotliDecompress !== 'function') this.skip();
+		const url = `${base}no-content/brotli`;
+		return fetch(url).then(res => {
+			expect(res.status).to.equal(204);
+			expect(res.statusText).to.equal('No Content');
+			expect(res.headers.get('content-encoding')).to.equal('br');
+			expect(res.ok).to.be.true;
+			return res.text().then(result => {
+				expect(result).to.be.a('string');
+				expect(result).to.be.empty;
+			});
+		});
+	});
+
 	it('should skip decompression if unsupported', function() {
 		const url = `${base}sdch`;
 		return fetch(url).then(res => {