net: fix bufferSize

doc/api/deprecations.md

@@ -2751,6 +2751,19 @@ const moduleParents = Object.values(require.cache)
   .filter((m) => m.children.includes(module));
 ```
 
+<a id="DEP0XXX"></a>
+### DEP0XXX: `socket.bufferSize`
+<!-- YAML
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/REPLACEME
+    description: Documentation-only deprecation.
+-->
+
+Type: Documentation-only
+
+[`socket.bufferSize`][] is just an alias for [`writable.writableLength`][].
+
 [`--pending-deprecation`]: cli.html#cli_pending_deprecation
 [`--throw-deprecation`]: cli.html#cli_throw_deprecation
 [`Buffer.allocUnsafeSlow(size)`]: buffer.html#buffer_class_method_buffer_allocunsafeslow_size
@@ -2824,6 +2837,7 @@ const moduleParents = Object.values(require.cache)
 [`script.createCachedData()`]: vm.html#vm_script_createcacheddata
 [`setInterval()`]: timers.html#timers_setinterval_callback_delay_args
 [`setTimeout()`]: timers.html#timers_settimeout_callback_delay_args
+[`socket.bufferSize`]: net.html#net_socket_buffersize
 [`timeout.ref()`]: timers.html#timers_timeout_ref
 [`timeout.refresh()`]: timers.html#timers_timeout_refresh
 [`timeout.unref()`]: timers.html#timers_timeout_unref
@@ -2860,6 +2874,7 @@ const moduleParents = Object.values(require.cache)
 [`util`]: util.html
 [`worker.exitedAfterDisconnect`]: cluster.html#cluster_worker_exitedafterdisconnect
 [`worker.terminate()`]: worker_threads.html#worker_threads_worker_terminate
+[`writable.writableLength`]: stream.html#stream_writable_writablelength
 [`zlib.bytesWritten`]: zlib.html#zlib_zlib_byteswritten
 [Legacy URL API]: url.html#url_legacy_url_api
 [NIST SP 800-38D]: https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38d.pdf

doc/api/net.md

@@ -529,8 +529,12 @@ socket as reported by the operating system:
 ### `socket.bufferSize`
 <!-- YAML
 added: v0.3.8
+deprecated:
+  - REPLACEME
 -->
 
+> Stability: 0 - Deprecated: Use [`writable.writableLength`][] instead.
+
 * {integer}
 
 This property shows the number of characters buffered for writing. The buffer
@@ -1268,6 +1272,7 @@ Returns `true` if input is a version 6 IP address, otherwise returns `false`.
 [`socket.setEncoding()`]: #net_socket_setencoding_encoding
 [`socket.setTimeout()`]: #net_socket_settimeout_timeout_callback
 [`socket.setTimeout(timeout)`]: #net_socket_settimeout_timeout_callback
+[`writable.writableLength`]: stream.html#stream_writable_writablelength
 [`writable.destroyed`]: stream.html#stream_writable_destroyed
 [`writable.destroy()`]: stream.html#stream_writable_destroy_error
 [`writable.end()`]: stream.html#stream_writable_end_chunk_encoding_callback

lib/net.js

@@ -541,7 +541,7 @@ ObjectDefineProperty(Socket.prototype, 'readyState', {
 ObjectDefineProperty(Socket.prototype, 'bufferSize', {
   get: function() {
     if (this._handle) {
-      return this[kLastWriteQueueSize] + this.writableLength;
+      return this.writableLength;
     }
   }
 });

test/parallel/test-tls-buffersize.js

@@ -31,7 +31,7 @@ server.listen(0, common.mustCall(() => {
 
     for (let i = 1; i < iter; i++) {
       client.write('a');
-      assert.strictEqual(client.bufferSize, i + 1);
+      assert.strictEqual(client.bufferSize, i);
     }
 
     client.on('finish', common.mustCall(() => {

test/parallel/test-tls-streamwrap-buffersize.js

@@ -56,7 +56,7 @@ const net = require('net');
 
         for (let i = 1; i < iter; i++) {
           client.write('a');
-          assert.strictEqual(client.bufferSize, i + 1);
+          assert.strictEqual(client.bufferSize, i);
         }
 
         client.on('end', common.mustCall());