Add setHeaders option

closes #5

Author: dougwilson

History.md

@@ -1,6 +1,7 @@
 unreleased
 ==========
 
+  * Add `setHeaders` option
   * Include HTML link in redirect response
   * deps: [email protected]
     - Accept string for `maxAge` (converted by `ms`)

Readme.md

@@ -30,6 +30,7 @@ Options:
 - `index` Default file name, defaults to `'index.html'`
 - `maxAge` Browser cache maxAge in milliseconds. This can also be a string accepted by the [ms](https://www.npmjs.org/package/ms#readme) module. defaults to `0`
 - `redirect` Redirect to trailing "/" when the pathname is a dir. defaults to `true`
+- `setHeaders` Function to set custom headers on response.
 
 ## Examples
 
@@ -65,6 +66,25 @@ app.use(serveStatic('public/ftp', {'index': ['default.html', 'default.htm']}))
 app.listen(3000)
 ```
 
+### Serve all files as downloads
+
+```js
+var express = require('express')
+var serveStatic = require('serve-static')
+
+var app = express()
+
+app.use(serveStatic('public/ftp', {
+  'index': false,
+  'setHeaders': setHeaders
+}))
+app.listen(3000)
+
+function setHeaders(res, path) {
+  res.attachment(path)
+}
+```
+
 ## License
 
 The MIT License (MIT)

index.js

@@ -59,6 +59,14 @@ exports = module.exports = function(root, options){
   // default redirect
   var redirect = false !== options.redirect;
 
+  // headers listener
+  var setHeaders = options.setHeaders
+  delete options.setHeaders
+
+  if (setHeaders && typeof setHeaders !== 'function') {
+    throw new TypeError('option setHeaders must be function')
+  }
+
   // setup options for send
   options.maxage = options.maxage || options.maxAge || 0;
   options.root = root;
@@ -94,6 +102,11 @@ exports = module.exports = function(root, options){
       stream.on('directory', next)
     }
 
+    // add headers listener
+    if (setHeaders) {
+      stream.on('headers', setHeaders)
+    }
+
     // forward non-404 errors
     stream.on('error', function error(err) {
       next(err.status === 404 ? null : err)

test/test.js

@@ -190,6 +190,51 @@ describe('serveStatic()', function(){
     })
   })
 
+  describe('setHeaders', function () {
+    it('should reject non-functions', function () {
+      serveStatic.bind(null, fixtures, {'setHeaders': 3}).should.throw(/setHeaders.*function/)
+    })
+
+    it('should get called when sending file', function(done){
+      var server = createServer(fixtures, {'setHeaders': function (res) {
+        res.setHeader('x-custom', 'set')
+      }})
+
+      request(server)
+      .get('/nums')
+      .expect('x-custom', 'set')
+      .expect(200, done)
+    })
+
+    it('should not get called on 404', function(done){
+      var server = createServer(fixtures, {'setHeaders': function (res) {
+        res.setHeader('x-custom', 'set')
+      }})
+
+      request(server)
+      .get('/bogus')
+      .expect(404, function (err, res) {
+        if (err) return done(err)
+        res.headers.should.not.have.property('x-custom')
+        done()
+      })
+    })
+
+    it('should not get called on redirect', function(done){
+      var server = createServer(fixtures, {'setHeaders': function (res) {
+        res.setHeader('x-custom', 'set')
+      }})
+
+      request(server)
+      .get('/users')
+      .expect(303, function (err, res) {
+        if (err) return done(err)
+        res.headers.should.not.have.property('x-custom')
+        done()
+      })
+    })
+  })
+
   describe('when traversing passed root', function(){
     var server;
     before(function () {