Merge pull request #9 from fastify/keep-this-context

Keep this context

README.md

@@ -42,6 +42,26 @@ function _runMiddlewares (err, req, res) {
   // => routing function
 }
 ```
+<a name="keep-context"></a>
+#### Keep the context
+If you need it you can also keep the context of the calling function by calling `run` with `run(req, res, this)`, in this way you can avoid closures allocation.
+
+```js
+http
+  .createServer(function handler (req, res) {
+    middie.run(req, res, { context: 'object' })
+  })
+  .listen(3000)
+
+function _runMiddlewares (err, req, res, ctx) {
+  if (err) {
+    console.log(err)
+    res.end(err)
+    return
+  }
+  console.log(ctx)
+}
+```
 
 <a name="restrict-usage"></a>
 #### Restrict middleware execution to a certain path(s)

middie.js

@@ -24,16 +24,17 @@ function middie (complete) {
     return this
   }
 
-  function run (req, res) {
+  function run (req, res, ctx) {
     if (!middlewares.length) {
-      complete(null, req, res)
+      complete(null, req, res, ctx)
       return
     }
 
     const holder = pool.get()
     holder.req = req
     holder.res = res
     holder.url = sanitizeUrl(req.url)
+    holder.context = ctx
     holder.done()
   }
 
@@ -42,19 +43,22 @@ function middie (complete) {
     this.req = null
     this.res = null
     this.url = null
+    this.context = null
     this.i = 0
 
     var that = this
     this.done = function (err) {
       const req = that.req
       const res = that.res
       const url = that.url
+      const context = that.context
       const i = that.i++
 
       if (err || middlewares.length === i) {
-        complete(err, req, res)
+        complete(err, req, res, context)
         that.req = null
         that.res = null
+        that.context = null
         that.i = 0
         pool.release(that)
       } else {

test.js

@@ -205,3 +205,25 @@ test('Should strip the url to only match the pathname', t => {
 
   instance.run(req, res)
 })
+
+test('should keep the context', t => {
+  t.plan(6)
+
+  const instance = middie(function (err, a, b, ctx) {
+    t.error(err)
+    t.equal(a, req)
+    t.equal(b, res)
+    t.ok(ctx.key)
+  })
+  const req = {
+    url: '/test'
+  }
+  const res = {}
+
+  t.equal(instance.use(function (req, res, next) {
+    t.pass('function called')
+    next()
+  }), instance)
+
+  instance.run(req, res, { key: true })
+})