http2: add bytesWritten test for Http2Stream

note that this is for the `Http2Server` class. I'll soon be
adding one for `Http2SecureServer` as well.
Refs: #29829
PR-URL: #33162
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: rexagod

test/parallel/test-http2-byteswritten-server.js

@@ -0,0 +1,28 @@
+'use strict';
+
+constcommon=require('../common');
+if(!common.hasCrypto)
+common.skip('missing crypto');
+constassert=require('assert');
+consthttp2=require('http2');
+
+consthttp2Server=http2.createServer(common.mustCall(function(req,res){
+res.socket.on('finish',common.mustCall(()=>{
+assert(req.socket.bytesWritten>0);// 1094
+}));
+res.writeHead(200,{'Content-Type': 'text/plain'});
+res.write(Buffer.from('1'.repeat(1024)));
+res.end();
+}));
+
+http2Server.listen(0,common.mustCall(function(){
+constURL=`http://localhost:${http2Server.address().port}`;
+consthttp2client=http2.connect(URL,{protocol: 'http:'});
+constreq=http2client.request({':method': 'GET',':path': '/'});
+req.on('data',common.mustCall());
+req.on('end',common.mustCall(function(){
+http2client.close();
+http2Server.close();
+}));
+req.end();
+}));