net: inline and simplify onSocketEnd

PR-URL: https://github.com/nodejs/node/pull/18607
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/net.js

@@ -256,7 +256,7 @@ function Socket(options) {
   }
 
   // shut down the socket when we're finished with it.
-  this.on('_socketEnd', onSocketEnd);
+  this.on('end', onReadableStreamEnd);
 
   initSocketHandle(this);
 
@@ -360,32 +360,6 @@ function afterShutdown(status, handle) {
   }
 }
 
-// the EOF has been received, and no more bytes are coming.
-// if the writable side has ended already, then clean everything
-// up.
-function onSocketEnd() {
-  // XXX Should not have to do as much in this function.
-  // ended should already be true, since this is called *after*
-  // the EOF errno and onread has eof'ed
-  debug('onSocketEnd', this._readableState);
-  this._readableState.ended = true;
-  if (this._readableState.endEmitted) {
-    this.readable = false;
-    maybeDestroy(this);
-  } else {
-    this.once('end', function end() {
-      this.readable = false;
-      maybeDestroy(this);
-    });
-    this.read(0);
-  }
-
-  if (!this.allowHalfOpen) {
-    this.write = writeAfterFIN;
-    this.destroySoon();
-  }
-}
-
 // Provide a better error message when we call end() as a result
 // of the other side sending a FIN.  The standard 'write after end'
 // is overly vague, and makes it seem like the user's code is to blame.
@@ -537,6 +511,12 @@ Socket.prototype.end = function(data, encoding, callback) {
 };
 
 
+// Called when the 'end' event is emitted.
+function onReadableStreamEnd() {
+  maybeDestroy(this);
+}
+
+
 // Call whenever we set writable=false or readable=false
 function maybeDestroy(socket) {
   if (!socket.readable &&
@@ -651,10 +631,11 @@ function onread(nread, buffer) {
   // Do it before `maybeDestroy` for correct order of events:
   // `end` -> `close`
   self.push(null);
+  self.read(0);
 
-  if (self.readableLength === 0) {
-    self.readable = false;
-    maybeDestroy(self);
+  if (!self.allowHalfOpen) {
+    self.write = writeAfterFIN;
+    self.destroySoon();
   }
 
   // internal end event so that we know that the actual socket

test/parallel/test-http-connect.js

@@ -65,7 +65,8 @@ server.listen(0, common.mustCall(() => {
 
     // the stream.Duplex onend listener
     // allow 0 here, so that i can run the same test on streams1 impl
-    assert(socket.listeners('end').length <= 1);
+    assert(socket.listenerCount('end') <= 2,
+           `Found ${socket.listenerCount('end')} end listeners`);
 
     assert.strictEqual(socket.listeners('free').length, 0);
     assert.strictEqual(socket.listeners('close').length, 0);