test: make HTTP/1.0 connection test more robust

[FliegendeWurst]

Fixes: #47200

This is a more robust alternative to #47316

[lpinca]

Suggested change

socket.end(); // we are done sending data

This invalidate the test. The socket should be closed by the server.

[FliegendeWurst]

This only closes one end of the socket, as I understand it. But I will remove it.

[github-actions]

Failed to start CI

   ⚠  Something was pushed to the Pull Request branch since the last approving review.
   ✘  Refusing to run CI on potentially unsafe PR

https://github.com/nodejs/node/actions/runs/11986219813

[FliegendeWurst]

(lint failed due to unused common)

[lpinca]

Use require('../common');. Do not remove it completely, it is mandatory.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/63660/

[FliegendeWurst]

parallel.test-http-server-headers-timeout-keepalive failed. I don't see how it relates to this change.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 87.99%. Comparing base (3178a76) to head (401f5f2).
Report is 560 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff            @@
##             main   #55959    +/-   ##
========================================
  Coverage   87.99%   87.99%            
========================================
  Files         653      653            
  Lines      187852   188091   +239     
  Branches    35888    35945    +57     
========================================
+ Hits       165295   165514   +219     
- Misses      15729    15742    +13     
- Partials     6828     6835     +7     

see 29 files with indirect coverage changes

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/63666/

[lpinca]

@FliegendeWurst to actually verify that the socket is closed immediately after sending the response, I would refactor the test as follows

diff --git a/test/parallel/test-http-remove-connection-header-persists-connection.js b/test/parallel/test-http-remove-connection-header-persists-connection.js
index df7e39ae94..4afb863c44 100644
--- a/test/parallel/test-http-remove-connection-header-persists-connection.js
+++ b/test/parallel/test-http-remove-connection-header-persists-connection.js
@@ -10,6 +10,13 @@ const server = http.createServer(function(request, response) {
   // For HTTP/1.0, the connection should be closed after the response automatically.
   response.removeHeader('connection');
 
+  if (request.httpVersion === '1.0') {
+    const socket = request.socket;
+    response.on('finish', common.mustCall(function() {
+      assert.ok(socket.writableEnded);
+    }));
+  }
+
   response.end('beep boop\n');
 });
 
@@ -49,10 +56,7 @@ function makeHttp10Request(cb) {
                'Host: localhost:' + server.address().port + '\r\n' +
                 '\r\n');
     socket.resume(); // Ignore the response itself
-
-    setTimeout(function() {
-      cb(socket);
-    }, common.platformTimeout(50));
+    socket.on('close', cb);
   });
 }
 
@@ -62,9 +66,7 @@ server.listen(0, function() {
       // Both HTTP/1.1 requests should have used the same socket:
       assert.strictEqual(firstSocket, secondSocket);
 
-      makeHttp10Request(function(socket) {
-        // The server should have immediately closed the HTTP/1.0 socket:
-        assert.strictEqual(socket.closed, true);
+      makeHttp10Request(function() {
         server.close();
       });
     });

[FliegendeWurst]

Done as suggested. I also checked the http server: the socket should be closed before our 'finish' handler is called.