test: deflake test-http-remove-header-stays-removed

Instead of relying on a timer, verify that `socket.end()` is called when
the `'finish'` event is emitted on the `ServerResponse` object.
PR-URL: #55004
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Jake Yuesong Li <jake.yuesong@gmail.com>

Author: lpinca

test/parallel/test-http-remove-header-stays-removed.js

@@ -25,7 +25,9 @@ const assert = require('assert');
 
 consthttp=require('http');
 
-constserver=http.createServer(function(request,response){
+constserver=http.createServer(common.mustCall(function(request,response){
+constsocket=response.socket;
+
 // Removed headers should stay removed, even if node automatically adds them
 // to the output:
 response.removeHeader('connection');
@@ -36,32 +38,29 @@ const server = http.createServer(function(request, response) {
 response.removeHeader('date');
 response.setHeader('date','coffee o clock');
 
-response.end('beep boop\n');
-});
-
-letresponse='';
+response.on('finish',common.mustCall(function(){
+// The socket should be closed immediately, with no keep-alive, because
+// no content-length or transfer-encoding are used.
+assert.strictEqual(socket.writableEnded,true);
+}));
 
-process.on('exit',function(){
-assert.strictEqual(response,'beep boop\n');
-console.log('ok');
-});
+response.end('beep boop\n');
+}));
 
 server.listen(0,function(){
 http.get({port: this.address().port},function(res){
 assert.strictEqual(res.statusCode,200);
 assert.deepStrictEqual(res.headers,{date: 'coffee o clock'});
 
+letresponse='';
 res.setEncoding('ascii');
 res.on('data',function(chunk){
 response+=chunk;
-if(response==='beep boop\n'){
-setTimeout(function(){
-// The socket should be closed immediately, with no keep-alive, because
-// no content-length or transfer-encoding are used:
-assert.strictEqual(res.socket.closed,true);
-server.close();
-},common.platformTimeout(15));
-}
+});
+
+res.on('end',function(){
+assert.strictEqual(response,'beep boop\n');
+server.close();
 });
 });
 });