fs: remove undocumented .destroy callbacks

The destroy() method of fs.ReadStream and fs.WriteStream takes a callback.
It's a leftover from the node 0.1 days, undocumented and not part of the
streams API. Remove it.

lib/fs.js

@@ -1364,25 +1364,19 @@ ReadStream.prototype._emitData = function(d) {
 };
 
 
-ReadStream.prototype.destroy = function(cb) {
+ReadStream.prototype.destroy = function() {
   var self = this;
 
-  if (!this.readable) {
-    if (cb) process.nextTick(function() { cb(null); });
-    return;
-  }
+  if (!this.readable) return;
   this.readable = false;
 
   function close() {
     fs.close(self.fd, function(err) {
       if (err) {
-        if (cb) cb(err);
         self.emit('error', err);
-        return;
+      } else {
+        self.emit('close');
       }
-
-      if (cb) cb(null);
-      self.emit('close');
     });
   }
 
@@ -1570,25 +1564,19 @@ WriteStream.prototype.end = function(data, encoding, cb) {
   this.flush();
 };
 
-WriteStream.prototype.destroy = function(cb) {
+WriteStream.prototype.destroy = function() {
   var self = this;
 
-  if (!this.writable) {
-    if (cb) process.nextTick(function() { cb(null); });
-    return;
-  }
+  if (!this.writable) return;
   this.writable = false;
 
   function close() {
     fs.close(self.fd, function(err) {
       if (err) {
-        if (cb) { cb(err); }
         self.emit('error', err);
-        return;
+      } else {
+        self.emit('close');
       }
-
-      if (cb) { cb(null); }
-      self.emit('close');
     });
   }
 

test/simple/test-fs-read-stream.js

@@ -34,7 +34,7 @@ var fs = require('fs');
 var fn = path.join(common.fixturesDir, 'elipses.txt');
 var rangeFile = path.join(common.fixturesDir, 'x.txt');
 
-var callbacks = { open: 0, end: 0, close: 0, destroy: 0 };
+var callbacks = { open: 0, end: 0, close: 0 };
 
 var paused = false;
 
@@ -82,17 +82,6 @@ file.on('close', function() {
   //assert.equal(fs.readFileSync(fn), fileContent);
 });
 
-var file2 = fs.createReadStream(fn);
-file2.destroy(function(err) {
-  assert.ok(!err);
-  callbacks.destroy++;
-
-  file2.destroy(function(err) {
-    assert.ok(!err);
-    callbacks.destroy++;
-  });
-});
-
 var file3 = fs.createReadStream(fn, {encoding: 'utf8'});
 file3.length = 0;
 file3.on('data', function(data) {
@@ -112,10 +101,7 @@ file3.on('close', function() {
 process.on('exit', function() {
   assert.equal(1, callbacks.open);
   assert.equal(1, callbacks.end);
-  assert.equal(2, callbacks.destroy);
-
   assert.equal(2, callbacks.close);
-
   assert.equal(30000, file.length);
   assert.equal(10000, file3.length);
 });