Ensure fd is closed in the following cases:

1. The `res` ends before it is passed to `send().pipe()`
2. The `res` ends after pipe but before the `open` event

index.js

@@ -24,6 +24,7 @@ var fs = require('fs')
 var mime = require('mime')
 var ms = require('ms')
 var onFinished = require('on-finished')
+var isFinished = onFinished.isFinished
 var parseRange = require('range-parser')
 var path = require('path')
 var statuses = require('statuses')
@@ -181,6 +182,8 @@ function SendStream (req, path, options) {
     ? opts.fd
     : null
 
+  this.autoClose = opts.autoClose !== false
+
   if (!this._root && opts.from) {
     this.from(opts.from)
   }
@@ -476,7 +479,35 @@ SendStream.prototype.redirect = function redirect (path) {
 }
 
 /**
- * Pipe to `res.
+ * End the stream.
+ *
+ * @private
+ */
+
+SendStream.prototype.end = function end () {
+  this.send = this.close
+  if (this._stream) this._stream.destroy()
+  if (this.autoClose) this.close()
+}
+
+/**
+ * Close the file descriptor.
+ *
+ * @private
+ */
+
+SendStream.prototype.close = function close () {
+  if (typeof this.fd !== 'number') return
+  var self = this
+  fs.close(this.fd, function (err) { /* istanbul ignore next */
+    if (err && !BAD_FD_REGEXP.test(err.code)) return self.onFileSystemError(err)
+    self.fd = null
+    self.emit('close')
+  })
+}
+
+/**
+ * Pipe to `res`.
  *
  * @param {Stream} res
  * @return {Stream} res
@@ -492,18 +523,12 @@ SendStream.prototype.pipe = function pipe (res) {
   this.res = res
 
   // response finished, done with the fd
-  onFinished(res, function onfinished () {
-    var autoClose = self.options.autoClose !== false
-    if (self._stream) self._stream.destroy()
-    if (typeof self.fd === 'number' && autoClose) {
-      fs.close(self.fd, function (err) {
-        /* istanbul ignore next */
-        if (err && !BAD_FD_REGEXP.test(err.code)) return self.onFileSystemError(err)
-        self.fd = null
-        self.emit('close')
-      })
-    }
-  })
+  if (isFinished(res)) {
+    this.end()
+    return res
+  }
+
+  onFinished(res, this.end.bind(this))
 
   if (typeof this.fd === 'number') {
     fs.fstat(this.fd, function (err, stat) {
@@ -608,6 +633,8 @@ SendStream.prototype.send = function send (path, stat) {
   var ranges = req.headers.range
   var offset = options.start || 0
 
+  if (isFinished(res)) return this.end()
+
   if (res._header) {
     // impossible to send now
     this.headersAlreadySent()

test/send.js

@@ -24,6 +24,7 @@ var app = http.createServer(function (req, res) {
   .pipe(res)
 })
 
+var noop = Function.prototype
 var fsOpen = fs.open
 var fsClose = fs.close
 var fds = { opened: 0, closed: 0 }
@@ -934,10 +935,43 @@ describe('send(file, options)', function () {
       .get('/anything')
       .expect(500, done)
     })
+
+    it('should close the file descriptor if the response ends before pipe', function (done) {
+      fs.open(path.join(fixtures, '/name.txt'), 'r', function (err, fd) {
+        if (err) return done(err)
+        var app = http.createServer(function (req, res) {
+          res.end()
+          send(req, req.url, req.url === '/fd' ? {fd: fd} : {root: 'test/fixtures'})
+          .on('close', done)
+          .pipe(res)
+        })
+
+        request(app)
+        .get('/nums')
+        .expect(200, function () {
+          request(app)
+          .get('/fd')
+          .expect(200, noop)
+        })
+      })
+    })
+
+    it('should close the file descriptor if the response ends immediately after pipe', function (done) {
+      var app = http.createServer(function (req, res) {
+        send(req, req.url, {root: 'test/fixtures'})
+        .on('close', done)
+        .pipe(res)
+        res.end()
+      })
+
+      request(app)
+      .get('/name.txt')
+      .expect(200, noop)
+    })
   })
 
   describe('autoClose', function () {
-    it('should prevent the file descriptor from being closed automatically', function (done) {
+    it('should prevent the file descriptor from being closed automatically if set to `false`', function (done) {
       var resource = '/nums'
       fs.open(path.join(fixtures, resource), 'r', function (err, fd) {
         if (err) return done(err)