net: return this from destroy()

doc/api/net.md

@@ -643,6 +643,8 @@ callback.
 added: v0.1.90
 -->
 
+* Returns: {net.Socket}
+
 Ensures that no more I/O activity happens on this socket. Only necessary in
 case of errors (parse error or so).
 

doc/api/stream.md

@@ -515,8 +515,10 @@ A Writable stream in object mode will always ignore the `encoding` argument.
 added: v8.0.0
 -->
 
+* Returns: `this`
+
 Destroy the stream, and emit the passed error. After this call, the
-writible stream has ended. Implementors should not override this method,
+writable stream has ended. Implementors should not override this method,
 but instead implement [`writable._destroy`][writable-_destroy].
 
 ### Readable Streams

lib/internal/streams/destroy.js

@@ -14,7 +14,7 @@ function destroy(err, cb) {
  (!this._writableState || !this._writableState.errorEmitted)) {
  process.nextTick(emitErrorNT, this, err);
  }
- return;
+ return this;
  }
 
  // we set destroyed to true before firing error callbacks in order
@@ -39,6 +39,8 @@ function destroy(err, cb) {
  cb(err);
  }
  });
+
+ return this;
 }
 
 function undestroy() {

test/parallel/test-net-socket-destroy-send.js

@@ -10,7 +10,8 @@ server.listen(0, common.mustCall(function() {
  const conn = net.createConnection(port);
 
  conn.on('connect', common.mustCall(function() {
- conn.destroy();
+ // Test destroy returns this, even on multiple calls when it short-circuits.
+ assert.strictEqual(conn, conn.destroy().destroy());
  conn.on('error', common.mustCall(function(err) {
  assert.strictEqual(err.message, 'This socket is closed');
  }));