Expose filename to output stream. (fastify#61)

This is needed for additional plugins to perform transformations which
require knowledge of the path on the local filesystem.

README.md

@@ -83,6 +83,17 @@ If an error occurs while trying to send a file, the error will be passed
 to Fastify's error handler. You can set a custom error handler with
 [`fastify.setErrorHandler()`](https://www.fastify.io/docs/latest/Server-Methods/#seterrorhandler).
 
+### Payload `stream.filename`
+
+If you need to access the filename inside the `onSend` hook, you can use `payload.filename`.
+
+```js
+fastify.addHook('onSend', function (req, reply, payload, next) {
+  console.log(payload.filename)
+  next()
+})
+```
+
 ## License
 
 Licensed under [MIT](./LICENSE)

index.js

@@ -33,6 +33,10 @@ function fastifyStatic (fastify, opts, next) {
 
   function pumpSendToReply (request, reply, pathname) {
     const stream = send(request.raw, pathname, sendOptions)
+    var resolvedFilename
+    stream.on('file', function (file) {
+      resolvedFilename = file
+    })
 
     const wrap = new PassThrough({
       flush (cb) {
@@ -49,6 +53,11 @@ function fastifyStatic (fastify, opts, next) {
     wrap.socket = request.raw.socket
     wrap.finished = false
 
+    Object.defineProperty(wrap, 'filename', {
+      get () {
+        return resolvedFilename
+      }
+    })
     Object.defineProperty(wrap, 'statusCode', {
       get () {
         return reply.res.statusCode
@@ -104,7 +113,7 @@ function checkRootPathForErrors (rootPath) {
     return new Error('"root" option must be an absolute path')
   }
 
-  let pathStat
+  var pathStat
 
   try {
     pathStat = statSync(rootPath)

test/static.test.js

@@ -306,6 +306,59 @@ t.test('register /static/', t => {
   })
 })
 
+t.test('payload.filename is set', t => {
+  t.plan(3)
+
+  const pluginOptions = {
+    root: path.join(__dirname, '/static'),
+    prefix: '/static/'
+  }
+  const fastify = Fastify()
+  var gotFilename
+  fastify.register(fastifyStatic, pluginOptions)
+  fastify.addHook('onSend', function (req, reply, payload, next) {
+    gotFilename = payload.filename
+    next()
+  })
+
+  t.tearDown(fastify.close.bind(fastify))
+
+  fastify.listen(0, err => {
+    t.error(err)
+
+    fastify.server.unref()
+
+    t.test('/static/index.html', t => {
+      t.plan(5 + GENERIC_RESPONSE_CHECK_COUNT)
+      simple.concat({
+        method: 'GET',
+        url: 'http://localhost:' + fastify.server.address().port + '/static/index.html'
+      }, (err, response, body) => {
+        t.error(err)
+        t.strictEqual(response.statusCode, 200)
+        t.strictEqual(body.toString(), indexContent)
+        t.is(typeof gotFilename, 'string')
+        t.strictEqual(gotFilename, path.join(pluginOptions.root, 'index.html'))
+        genericResponseChecks(t, response)
+      })
+    })
+
+    t.test('/static/this/path/doesnt/exist.html', t => {
+      t.plan(3 + GENERIC_ERROR_RESPONSE_CHECK_COUNT)
+      simple.concat({
+        method: 'GET',
+        url: 'http://localhost:' + fastify.server.address().port + '/static/this/path/doesnt/exist.html',
+        followRedirect: false
+      }, (err, response, body) => {
+        t.error(err)
+        t.strictEqual(response.statusCode, 404)
+        t.is(typeof gotFilename, 'undefined')
+        genericErrorResponseChecks(t, response)
+      })
+    })
+  })
+})
+
 t.test('error responses can be customized with fastify.setErrorHandler()', t => {
   t.plan(2)