test: add maxConnections close reopen test

src/js/node/net.ts

@@ -89,6 +89,7 @@ function isIP(s): 0 | 4 | 6 {
 
 const bunTlsSymbol = Symbol.for("::buntls::");
 const bunSocketServerConnections = Symbol.for("::bunnetserverconnections::");
+const bunSocketServerDropped = Symbol.for("::bunnetserverdropped::");
 const bunSocketServerOptions = Symbol.for("::bunnetserveroptions::");
 const owner_symbol = Symbol("owner_symbol");
 
@@ -342,16 +343,17 @@ const ServerHandlers: SocketHandler = {
     const data = this.data;
     if (!data) return;
 
-    data.server[bunSocketServerConnections]--;
-    {
-      if (!data[kclosed]) {
-        data[kclosed] = true;
-        //socket cannot be used after close
-        detachSocket(data);
-        SocketEmitEndNT(data, err);
-        data.data = null;
-        socket[owner_symbol] = null;
-      }
+    if (!data[bunSocketServerDropped]) {
+      data.server[bunSocketServerConnections]--;
+    }
+
+    if (!data[kclosed]) {
+      data[kclosed] = true;
+      //socket cannot be used after close
+      detachSocket(data);
+      SocketEmitEndNT(data, err);
+      data.data = null;
+      socket[owner_symbol] = null;
     }
 
     data.server._emitCloseIfDrained();
@@ -383,6 +385,7 @@ const ServerHandlers: SocketHandler = {
           remotePort: _socket.remotePort,
           remoteFamily: _socket.remoteFamily || "IPv4",
         };
+        _socket[bunSocketServerDropped] = true;
         socket.end();
         self.emit("drop", data);
         return;
@@ -398,6 +401,7 @@ const ServerHandlers: SocketHandler = {
         remoteFamily: _socket.remoteFamily || "IPv4",
       };
 
+      _socket[bunSocketServerDropped] = true;
       socket.end();
 
       self.emit("drop", data);

test/js/node/test/parallel/test-net-server-max-connections-close-makes-more-available.js

@@ -0,0 +1,84 @@
+require("../common");
+const assert = require("assert");
+
+const net = require("net");
+
+// Sets the server's maxConnections property to 1.
+// Open 2 connections (connection 0 and connection 1).
+// Connection 0  should be accepted.
+// Connection 1 should be rejected.
+// Closes connection 0.
+// Open 2 more connections (connection 2 and 3).
+// Connection 2 should be accepted.
+// Connection 3 should be rejected.
+
+const connections = [];
+const received = [];
+const sent = [];
+
+function createConnection(index) {
+  console.error(`creating connection ${index}`);
+
+  return new Promise(function (resolve, reject) {
+    const connection = net.createConnection(server.address().port, function () {
+      const msg = String(index);
+      console.error(`sending message: ${msg}`);
+      this.write(msg);
+      sent.push(msg);
+    });
+
+    connection.on("error", function (err) {
+      assert.strictEqual(err.code, "ECONNRESET");
+      resolve();
+    });
+
+    connection.on("data", function (e) {
+      console.error(`connection ${index} received response`);
+      resolve();
+    });
+
+    connection.on("end", function () {
+      console.error(`ending ${index}`);
+      resolve();
+    });
+
+    connections[index] = connection;
+  });
+}
+
+function closeConnection(index) {
+  console.error(`closing connection ${index}`);
+  return new Promise(function (resolve, reject) {
+    connections[index].on("end", function () {
+      resolve();
+    });
+    connections[index].end();
+  });
+}
+
+const server = net.createServer(function (socket) {
+  socket.on("data", function (data) {
+    console.error(`received message: ${data}`);
+    received.push(String(data));
+    socket.write("acknowledged");
+  });
+});
+
+server.maxConnections = 1;
+
+server.listen(0, function () {
+  createConnection(0)
+    .then(createConnection.bind(null, 1))
+    .then(closeConnection.bind(null, 0))
+    .then(createConnection.bind(null, 2))
+    .then(createConnection.bind(null, 3))
+    .then(server.close.bind(server))
+    .then(closeConnection.bind(null, 2));
+});
+
+process.on("exit", function () {
+  // Confirm that all connections tried to send data...
+  assert.deepStrictEqual(sent, ["0", "1", "2", "3"]);
+  // ...but that only connections 0 and 2 were successful.
+  assert.deepStrictEqual(received, ["0", "2"]);
+});