net_uv: throw when people construct net.Socket(fd)

Easier to catch compatibility errors.

lib/net_uv.js

@@ -84,6 +84,17 @@ function Socket(options) {
 
   stream.Stream.call(this);
 
+  if (typeof options == 'number') {
+    // Legacy interface. Uncomment the following lines after
+    // libuv backend is stable and API compatibile with legaacy.
+    //   console.error('Deprecated interface net.Socket(fd).');
+    //   console.trace();
+    // Must support legacy interface. NPM depends on it.
+    // https://github.com/isaacs/npm/blob/c7824f412f0cb59d6f55cf0bc220253c39e6029f/lib/utils/output.js#L110
+    // TODO Before we can do this we need a way to open a uv_stream_t by fd.
+    throw new Error("Not yet implemented")
+  }
+
   // private
   this._handle = options && options.handle;
   initSocketHandle(this);
@@ -245,7 +256,7 @@ Socket.prototype.destroy = function(exception) {
 
   self._connectQueueCleanUp();
 
-  debug('destroy ' + this.fd);
+  debug('destroy');
 
   this.readable = this.writable = false;
 
@@ -256,7 +267,7 @@ Socket.prototype.destroy = function(exception) {
     this.server._emitCloseIfDrained();
   }
 
-  debug('close ' + this.fd);
+  debug('close');
   if (this._handle) {
     this._handle.close();
     this._handle = null;