rewrite with ES2015

.travis.yml

@@ -1,6 +1,5 @@
 language: node_js
 node_js:
-  - "0.12"
   - "4"
   - "5"
   - "6"

lib/application.js

@@ -3,22 +3,22 @@
 //
 // **License:** MIT
 
-var util = require('util')
-var http = require('http')
-var Stream = require('stream')
-var thunks = require('thunks')
-var accepts = require('accepts')
-var Cookies = require('cookies')
-var statuses = require('statuses')
-var EventEmitter = require('events')
-
-var contextProto = require('./context')
-var requestProto = require('./request')
-var responseProto = require('./response')
-var packageInfo = require('../package.json')
-
-var pwdReg = new RegExp(process.cwd().replace(/[.*+?^${}()|[\]\\]/g, '\\$&'), 'g')
-var OnErrorHeaderReg = /^(Accept|Allow|Retry-After|Warning|Access-Control-Allow-)/i
+const util = require('util')
+const http = require('http')
+const Stream = require('stream')
+const thunks = require('thunks')
+const accepts = require('accepts')
+const Cookies = require('cookies')
+const statuses = require('statuses')
+const EventEmitter = require('events')
+
+const contextProto = require('./context')
+const requestProto = require('./request')
+const responseProto = require('./response')
+const packageInfo = require('../package.json')
+
+const pwdReg = new RegExp(process.cwd().replace(/[.*+?^${}()|[\]\\]/g, '\\$&'), 'g')
+const OnErrorHeaderReg = /^(Accept|Allow|Retry-After|Warning|Access-Control-Allow-)/i
 
 module.exports = Toa
 Toa.NAME = packageInfo.name
@@ -27,7 +27,8 @@ Toa.AUTHORS = packageInfo.authors
 
 function Toa (server, mainHandle, options) {
   if (!(this instanceof Toa)) return new Toa(server, mainHandle, options)
-  var app = this
+  const app = this
+
   this.middleware = []
   this.request = Object.create(requestProto)
   this.response = Object.create(responseProto)
@@ -91,24 +92,23 @@ function Toa (server, mainHandle, options) {
     // this will improve concurrency performance
     this._preEndHooks = [nextTick]
 
-    var context = this
     this.on('error', this.onerror)
+
     // socket error should be handled by server's 'clientError' listener then destroy
-    res.on('finish', function () {
-      if (context._finished == null) {
-        context._finished = true // context finished successfully
-        context.emit('finish')
+    res.on('finish', () => {
+      if (this._finished == null) {
+        this._finished = true // context finished successfully
+        this.emit('finish')
       }
     })
     // Maybe no 'close' event on res, we should listen req.
-    req.on('close', function () {
-      if (context._finished == null) {
-        context._finished = false // context finished unexpectedly
-        context.emit('close')
+    req.on('close', () => {
+      if (this._finished == null) {
+        this._finished = false // context finished unexpectedly
+        this.emit('close')
       }
     })
   }
-
   Context.prototype = app.context
   Context.prototype.constructor = Context
   this.Context = Context
@@ -135,7 +135,7 @@ function Toa (server, mainHandle, options) {
     this.errorHandle = isFn(options.onerror) ? options.onerror : null
   }
 
-  var config = {
+  const config = {
     proxy: false,
     poweredBy: 'Toa',
     subdomainOffset: 2,
@@ -144,15 +144,9 @@ function Toa (server, mainHandle, options) {
 
   Object.defineProperty(this, 'config', {
     enumerable: true,
-    get: function () {
-      return config
-    },
-    set: function (obj) {
-      var keys = Object.keys(obj || {})
-      if (!keys.length) throw new Error(util.inspect(obj) + ' is invalid config object.')
-      keys.forEach(function (key) {
-        config[key] = obj[key]
-      })
+    get: () => config,
+    set: (obj) => {
+      for (let key of Object.keys(obj)) config[key] = obj[key]
     }
   })
 }
@@ -197,20 +191,20 @@ Toa.prototype.listen = function () {
  * @api public
  */
 Toa.prototype.toListener = function () {
-  var Context = this.Context
-  var debug = this.debug
-  var errorHandle = this.errorHandle || noOp
+  const Context = this.Context
+  const debug = this.debug
+  const errorHandle = this.errorHandle || noOp
 
-  var middleware = this.middleware.slice()
+  const middleware = this.middleware.slice()
   if (this.mainHandle) middleware.push(toThunkableFn(this.mainHandle))
-  middleware.push(function (done) { this.seq(this.onPreEnd)(done) })
 
-  function worker (done) {
-    this.seq(middleware)(done)
+  function * worker () {
+    for (let fn of middleware) yield fn
+    for (let fn of this.onPreEnd) yield fn
   }
 
   return function requestListener (req, res) {
-    var ctx = new Context(req, res)
+    let ctx = new Context(req, res)
     res.statusCode = 404
     ctx.thunk = thunks(new Scope(ctx, errorHandle, debug))
     ctx.seq = ctx.thunk.seq
@@ -228,50 +222,54 @@ Toa.prototype.onerror = function (err) {
   // ignore null and response error
   if (err.expose || (err.status && err.status < 500)) return
   if (!util.isError(err)) err = new Error('non-error thrown: ' + util.inspect(err))
-  var msg = err.stack || err.toString()
+  let msg = err.stack || err.toString()
   console.error(msg.replace(/^/gm, '  '))
 }
 
-function Scope (ctx, errorHandle, debug) {
-  this.ctx = ctx
-  this.errorHandle = errorHandle
-  this.debug = debug
-  this.stopped = false
-}
-util.inherits(Scope, thunks.Scope)
-
-Scope.prototype.onstop = function (sig) {
-  var ctx = this.ctx
-  if (this.stopped) return ctx.onerror(ctx.createError(sig, 500))
-
-  this.stopped = true
-  if (ctx.status === 404) {
-    ctx.status = 418
-    ctx.message = sig.message
+/**
+ * Scope of context.thunk.
+ *
+ * @api private
+ */
+class Scope extends thunks.Scope {
+  constructor (ctx, errorHandle, debug) {
+    super()
+    this.ctx = ctx
+    this.errorHandle = errorHandle
+    this.debug = debug
+    this.stopped = false
   }
-  ctx.seq(ctx.onPreEnd)(respond)
-}
-
-Scope.prototype.onerror = function (err) {
-  var ctx = this.ctx
-  if (err == null) return
-  try {
-    err = this.errorHandle.call(ctx, err) || err
-  } catch (error) {
-    err = error
+  onstop (sig) {
+    let ctx = this.ctx
+    if (this.stopped) return ctx.onerror(ctx.createError(sig, 500))
+    this.stopped = true
+    if (ctx.status === 404) {
+      ctx.status = 418
+      ctx.message = sig.message
+    }
+    ctx.seq(ctx.onPreEnd)(respond)
+  }
+  onerror (err) {
+    let ctx = this.ctx
+    if (err == null) return
+    try {
+      err = this.errorHandle.call(ctx, err) || err
+    } catch (error) {
+      err = error
+    }
+    // if err === true, ignore err and response to client
+    if (err === true) respond.call(ctx)
+    else ctx.onerror(err)
   }
-  // if err === true, ignore err and response to client
-  if (err === true) respond.call(ctx)
-  else ctx.onerror(err)
 }
 
 /**
  * Response middleware.
  */
 function respond () {
-  var res = this.res
-  var body = this.body
-  var code = this.status
+  let res = this.res
+  let body = this.body
+  let code = this.status
 
   if (this.respond === false) return endContext(this)
   if (res.headersSent || this._finished != null) return
@@ -296,8 +294,7 @@ function respond () {
     body.pipe(res)
     // to ensure `res.headersSent === true` before `context.emit("end")`
     // if "error" occured before "data", it will goto `onResError(error)`
-    var ctx = this
-    body.once('data', function () { endContext(ctx) })
+    body.once('data', () => endContext(this))
     return
   } else {
     // body: json
@@ -331,12 +328,12 @@ function onResError (err) {
     return
   }
   // unset headers
-  var _headers = this.res._headers
+  let _headers = this.res._headers
   if (_headers) {
     // retain headers on error
-    Object.keys(_headers).map(function (key) {
+    for (let key of Object.keys(_headers)) {
       if (!OnErrorHeaderReg.test(key)) delete _headers[key]
-    })
+    }
   }
   // force text/plain
   this.type = 'text'
@@ -345,7 +342,7 @@ function onResError (err) {
   else if (typeof err.status !== 'number' || !statuses[err.status]) this.status = 500
   else this.status = err.status
 
-  var msg = err.expose ? err.message : statuses[this.status]
+  let msg = err.expose ? err.message : statuses[this.status]
   // hide server directory for error response
   this.body = msg.replace(pwdReg, '[application]')
   respond.call(this)

lib/context.js

@@ -1,12 +1,16 @@
 'use strict'
 // Modified from https://github.com/koajs/koa/tree/master/lib
 
-var destroy = require('destroy')
-var delegate = require('delegates')
-var EventEmitter = require('events')
-var createError = require('http-errors')
-var IncomingMessage = require('http').IncomingMessage
-var proto = module.exports = Object.create(EventEmitter.prototype)
+const destroy = require('destroy')
+const delegate = require('delegates')
+const EventEmitter = require('events')
+const createError = require('http-errors')
+const IncomingMessage = require('http').IncomingMessage
+
+/**
+ * context prototype.
+ */
+const proto = module.exports = Object.create(EventEmitter.prototype)
 
 /**
  * Create a error object, but don't throw
@@ -83,30 +87,21 @@ proto.end = function (message) {
  * @api public
  */
 proto.catchStream = function (stream) {
-  var ctx = this
   if (stream.toaCleanHandle) throw new Error('"catchStream" has been applied on the stream')
-  stream.toaCleanHandle = toaCleanHandle
-  // makesure ctx.onerror not exist
-  // because new error handle will emit error to ctx.onerror
-  stream.removeListener('error', ctx.onerror)
-  stream.on('error', toaCleanHandle)
-  this.on('finish', toaCleanHandle)
-  this.on('close', toaCleanHandle)
-  return stream
 
-  function toaCleanHandle (err) {
+  let toaCleanHandle = (err) => {
     stream.removeListener('error', toaCleanHandle)
-    ctx.removeListener('finish', toaCleanHandle)
-    ctx.removeListener('close', toaCleanHandle)
+    this.removeListener('finish', toaCleanHandle)
+    this.removeListener('close', toaCleanHandle)
     stream.toaCleanHandle = null
     // ensure that stream has the error listener to application
     // stream may emit error even if destroyed,
     // such as fs.createReadStream('not_exist_file')
-    if (!~stream.listeners('error').indexOf(ctx.onerror)) stream.on('error', ctx.onerror)
-    if (err != null) ctx.onerror(err)
-    else if (ctx._finished) {
+    if (!~stream.listeners('error').indexOf(this.onerror)) stream.on('error', this.onerror)
+    if (err != null) this.onerror(err)
+    else if (this._finished) {
       // finished normally
-      var shouldKeepAlive = stream instanceof IncomingMessage && stream.req.shouldKeepAlive
+      let shouldKeepAlive = stream instanceof IncomingMessage && stream.req.shouldKeepAlive
       // If incomingMessage stream is ended and agent is keepalived
       // the socket should be disbanded, in order not to be destroy.
       if (shouldKeepAlive && stream._readableState.ended === true) {
@@ -115,6 +110,14 @@ proto.catchStream = function (stream) {
     }
     destroy(stream)
   }
+  stream.toaCleanHandle = toaCleanHandle
+  // makesure ctx.onerror not exist
+  // because new error handle will emit error to this.onerror
+  stream.removeListener('error', this.onerror)
+  stream.on('error', toaCleanHandle)
+  this.on('finish', toaCleanHandle)
+  this.on('close', toaCleanHandle)
+  return stream
 }
 
 /**