Fix resourse cleaning

.travis.yml

@@ -1,5 +1,6 @@
 sudo: false
 language: node_js
 node_js:
+  - '8'
   - '6'
   - '4'

lib/middleware.js

@@ -22,10 +22,30 @@ module.exports = function createMiddleware (setup) {
         var appendFile = createFileAppender(options.fileStrategy, req, options.fields)
 
         result.files.forEach(function (file) {
-          file.stream = fs.createReadStream(file.path)
-
-          file.stream.on('open', function () {
+          var flushFn = function () {
             fs.unlink(file.path, function () {})
+            if (res) {
+              res.removeListener('finish', flushFn)
+              res.removeListener('close', flushFn)
+            }
+          }
+
+          if (res) {
+            res.on('finish', flushFn)
+            res.on('close', flushFn)
+          }
+
+          var stream
+
+          Object.defineProperty(file, 'stream', {
+            get: function () {
+              if (stream) {
+                return stream
+              }
+              stream = fs.createReadStream(file.path)
+              stream.on('open', flushFn)
+              return stream
+            }
           })
 
           appendFile(file)

package.json

@@ -23,20 +23,20 @@
     "busboy": "^0.2.13",
     "fs-temp": "^1.1.1",
     "on-finished": "^2.3.0",
-    "pify": "^2.3.0",
-    "pump": "^1.0.1",
+    "pify": "^3.0.0",
+    "pump": "^3.0.0",
     "stream-file-type": "^0.1.1",
-    "type-is": "^1.6.13"
+    "type-is": "^1.6.16"
   },
   "devDependencies": {
-    "assert-rejects": "^0.1.0",
-    "express": "^4.14.0",
-    "form-data": "^2.1.0",
-    "get-stream": "^2.3.1",
-    "hasha": "^2.2.0",
-    "mocha": "^3.1.0",
-    "standard": "^8.3.0",
-    "testdata-w3c-json-form": "^0.2.0"
+    "assert-rejects": "^0.1.1",
+    "express": "^4.16.3",
+    "form-data": "^2.3.2",
+    "get-stream": "^3.0.0",
+    "hasha": "^3.0.0",
+    "mocha": "^5.0.4",
+    "standard": "^11.0.0",
+    "testdata-w3c-json-form": "^0.2.1"
   },
   "engines": {
     "node": ">= 4.0.0"

test/express-integration.js

@@ -16,10 +16,15 @@ var port = 34279
 
 describe('Express Integration', function () {
   var app
+  var server
 
   before(function (done) {
     app = express()
-    app.listen(port, done)
+    server = app.listen(port, done)
+  })
+
+  after(function (done) {
+    server.close(done)
   })
 
   function submitForm (form, path) {
@@ -34,15 +39,15 @@ describe('Express Integration', function () {
         var finished = onFinished(req)
 
         resolve(Promise.all([body, finished]).then(function (result) {
-          return { res: res, body: result[0] }
+          return {res: res, body: result[0]}
         }))
       })
     })
   }
 
   it('should work with express error handling', function () {
-    var limits = { fileSize: 200 }
-    var upload = multer({ limits: limits })
+    var limits = {fileSize: 200}
+    var upload = multer({limits: limits})
     var router = new express.Router()
     var form = new FormData()