Fixed decompression for responses without Content-Length header (#5306)

* Fixed decompression for responses without `content-length` header;

* Add Brotli encoding to the `Accept-Encoding` header only if it is supported.

* `content-length` header transformation moved up;

Co-authored-by: Jay <jasonsaayman@gmail.com>

test/unit/adapters/http.js

@@ -33,6 +33,7 @@ function setTimeoutAsync(ms) {
 
 const pipelineAsync = util.promisify(stream.pipeline);
 const finishedAsync = util.promisify(stream.finished);
+const gzip = util.promisify(zlib.gzip);
 
 function toleranceRange(positive, negative) {
   const p = (1 + 1 / positive);
@@ -497,6 +498,23 @@ describe('supports http with nodejs', function () {
 
       await axios.get(LOCAL_SERVER_URL);
     });
+
+    it('should not fail if response content-length header is missing', async () => {
+      this.timeout(10000);
+
+      const str = 'zipped';
+      const zipped = await gzip(str);
+
+      server = await startHTTPServer((req, res) => {
+        res.setHeader('Content-Encoding', 'gzip');
+        res.removeHeader('Content-Length');
+        res.end(zipped);
+      });
+
+      const {data} = await axios.get(LOCAL_SERVER_URL);
+
+      assert.strictEqual(data, str);
+    });
   });
 
   it('should support UTF8', function (done) {
@@ -1411,7 +1429,6 @@ describe('supports http with nodejs', function () {
 
   it('should omit a user-agent if one is explicitly disclaimed', function (done) {
     server = http.createServer(function (req, res) {
-      console.log(req.headers);
       assert.equal("user-agent" in req.headers, false);
       assert.equal("User-Agent" in req.headers, false);
       res.end();