test: express integration

package.json

@@ -27,6 +27,7 @@
     "xtend": "^4.0.0"
   },
   "devDependencies": {
+    "express": "^4.13.1",
     "form-data": "^1.0.0-rc1",
     "fs-temp": "^0.1.2",
     "mocha": "^2.2.5",

test/express-integration.js

@@ -0,0 +1,53 @@
+/* eslint-env mocha */
+
+var assert = require('assert')
+
+var multer = require('../')
+var util = require('./_util')
+
+var express = require('express')
+var FormData = require('form-data')
+var concat = require('concat-stream')
+
+var port = 34279
+
+describe('Express Integration', function () {
+  it('should work with express error handling', function (done) {
+    var app = express()
+    var limits = { fileSize: 200 }
+    var upload = multer({ limits: limits })
+    var form = new FormData()
+
+    var routeCalled = 0
+    var errorCalled = 0
+
+    form.append('avatar', util.file('small1.dat'))
+
+    app.post('/profile', upload.single('avatar'), function (req, res, next) {
+      routeCalled++
+      res.status(200).end('')
+    })
+
+    app.use(function (err, req, res, next) {
+      assert.equal(err.code, 'LIMIT_FILE_SIZE')
+
+      errorCalled++
+      res.status(500).end('')
+    })
+
+    app.listen(port, function () {
+      form.submit('http://localhost:' + port + '/profile', function (err, res) {
+        assert.ifError(err)
+
+        res.pipe(concat({ encoding: 'buffer' }, function (body) {
+          assert.equal(routeCalled, 0)
+          assert.equal(errorCalled, 1)
+          assert.equal(body.length, 0)
+          assert.equal(res.statusCode, 500)
+
+          done()
+        }))
+      })
+    })
+  })
+})