Use mitt instead of EventEmitter. (#1398)

EventEmitter is quite bit and mitt is a pretty good/small replacement.

client/on-demand-entries-client.js

@@ -4,7 +4,7 @@ import Router from '../lib/router'
 import fetch from 'unfetch'
 
 Router.ready(() => {
-  Router.router.on('routeChangeComplete', ping)
+  Router.router.events.on('routeChangeComplete', ping)
 })
 
 async function ping () {

lib/router/index.js

@@ -39,7 +39,7 @@ coreMethodFields.forEach((field) => {
 
 routerEvents.forEach((event) => {
   SingletonRouter.ready(() => {
-    SingletonRouter.router.on(event, (...args) => {
+    SingletonRouter.router.events.on(event, (...args) => {
       const eventField = `on${event.charAt(0).toUpperCase()}${event.substring(1)}`
       if (SingletonRouter[eventField]) {
         SingletonRouter[eventField](...args)

lib/router/router.js

@@ -1,5 +1,5 @@
 import { parse, format } from 'url'
-import { EventEmitter } from 'events'
+import mitt from 'mitt'
 import fetch from 'unfetch'
 import evalScript from '../eval-script'
 import shallowEquals from '../shallow-equals'
@@ -25,9 +25,8 @@ if (typeof window !== 'undefined' && typeof navigator.serviceWorker !== 'undefin
     })
 }
 
-export default class Router extends EventEmitter {
+export default class Router {
   constructor (pathname, query, as, { Component, ErrorComponent, err } = {}) {
-    super()
     // represents the current component key
     this.route = toRoute(pathname)
 
@@ -37,6 +36,9 @@ export default class Router extends EventEmitter {
     // contain a map of promise of fetch routes
     this.fetchingRoutes = {}
 
+    // Handling Router Events
+    this.events = mitt()
+
     this.prefetchQueue = new PQueue({ concurrency: 2 })
     this.ErrorComponent = ErrorComponent
     this.pathname = pathname
@@ -98,7 +100,7 @@ export default class Router extends EventEmitter {
     const url = window.location.href
     const { pathname, query } = parse(url, true)
 
-    this.emit('routeChangeStart', url)
+    this.events.emit('routeChangeStart', url)
     const routeInfo = await this.getRouteInfo(route, pathname, query, url)
     const { error } = routeInfo
 
@@ -109,11 +111,11 @@ export default class Router extends EventEmitter {
     this.notify(routeInfo)
 
     if (error) {
-      this.emit('routeChangeError', error, url)
+      this.events.emit('routeChangeError', error, url)
       throw error
     }
 
-    this.emit('routeChangeComplete', url)
+    this.events.emit('routeChangeComplete', url)
   }
 
   back () {
@@ -156,7 +158,7 @@ export default class Router extends EventEmitter {
     const { shallow = false } = options
     let routeInfo = null
 
-    this.emit('routeChangeStart', as)
+    this.events.emit('routeChangeStart', as)
 
     // If shallow === false and other conditions met, we reuse the
     // existing routeInfo for this route.
@@ -173,18 +175,18 @@ export default class Router extends EventEmitter {
       return false
     }
 
-    this.emit('beforeHistoryChange', as)
+    this.events.emit('beforeHistoryChange', as)
     this.changeState(method, url, as, options)
     const hash = window.location.hash.substring(1)
 
     this.set(route, pathname, query, as, { ...routeInfo, hash })
 
     if (error) {
-      this.emit('routeChangeError', error, as)
+      this.events.emit('routeChangeError', error, as)
       throw error
     }
 
-    this.emit('routeChangeComplete', as)
+    this.events.emit('routeChangeComplete', as)
     return true
   }
 
@@ -356,7 +358,7 @@ export default class Router extends EventEmitter {
 
   abortComponentLoad (as) {
     if (this.componentLoadCancel) {
-      this.emit('routeChangeError', new Error('Route Cancelled'), as)
+      this.events.emit('routeChangeError', new Error('Route Cancelled'), as)
       this.componentLoadCancel()
       this.componentLoadCancel = null
     }

package.json

@@ -68,6 +68,7 @@
     "json-loader": "0.5.4",
     "loader-utils": "1.0.3",
     "minimist": "1.2.0",
+    "mitt": "1.1.0",
     "mkdirp-then": "1.2.0",
     "mv": "2.1.1",
     "mz": "2.6.0",

yarn.lock

@@ -1213,15 +1213,14 @@ chokidar@^1.4.3, chokidar@^1.6.1:
   optionalDependencies:
     fsevents "^1.0.0"
 
-chromedriver@2.26.1:
+chromedriver@2.28.0:
-  version "2.26.1"
+  version "2.28.0"
-  resolved "https://registry.npmjs.org/chromedriver/-/chromedriver-2.26.1.tgz#60036732224580d2699afd2626f5f26ea1f6c9fe"
+  resolved "https://registry.yarnpkg.com/chromedriver/-/chromedriver-2.28.0.tgz#ea0c383621dd27db340c612b85fe39414c16ec79"
   dependencies:
     adm-zip "^0.4.7"
-    kew "^0.5.0"
+    kew "^0.7.0"
-    mkdirp "^0.5.0"
+    mkdirp "^0.5.1"
-    npmconf "^2.1.1"
+    rimraf "^2.5.4"
-    rimraf "^2.0.3"
 
 ci-info@^1.0.0:
   version "1.0.0"
@@ -1322,13 +1321,6 @@ concat-stream@^1.4.6:
     readable-stream "^2.2.2"
     typedarray "^0.0.6"
 
-config-chain@~1.1.8:
-  version "1.1.11"
-  resolved "https://registry.npmjs.org/config-chain/-/config-chain-1.1.11.tgz#aba09747dfbe4c3e70e766a6e41586e1859fc6f2"
-  dependencies:
-    ini "^1.3.4"
-    proto-list "~1.2.1"
-
 console-browserify@^1.1.0:
   version "1.1.0"
   resolved "https://registry.npmjs.org/console-browserify/-/console-browserify-1.1.0.tgz#f0241c45730a9fc6323b206dbf38edc741d0bb10"
@@ -2504,7 +2496,7 @@ inherits@2.0.1:
   version "2.0.1"
   resolved "https://registry.npmjs.org/inherits/-/inherits-2.0.1.tgz#b17d08d326b4423e568eff719f91b0b1cbdf69f1"
 
-ini@^1.2.0, ini@^1.3.4, ini@~1.3.0:
+ini@~1.3.0:
   version "1.3.4"
   resolved "https://registry.npmjs.org/ini/-/ini-1.3.4.tgz#0537cb79daf59b59a1a517dff706c86ec039162e"
 
@@ -3082,9 +3074,9 @@ jsx-ast-utils@^1.3.4:
   dependencies:
     object-assign "^4.1.0"
 
-kew@^0.5.0:
+kew@^0.7.0:
-  version "0.5.0"
+  version "0.7.0"
-  resolved "https://registry.npmjs.org/kew/-/kew-0.5.0.tgz#ece11cb5d8d01a81f8ce804c8d0bba06e6b25ca2"
+  resolved "https://registry.yarnpkg.com/kew/-/kew-0.7.0.tgz#79d93d2d33363d6fdd2970b335d9141ad591d79b"
 
 kind-of@^3.0.2:
   version "3.1.0"
@@ -3351,6 +3343,10 @@ minimist@1.2.0, minimist@^1.1.0, minimist@^1.1.1, minimist@^1.2.0:
   version "1.2.0"
   resolved "https://registry.npmjs.org/minimist/-/minimist-1.2.0.tgz#a35008b20f41383eec1fb914f4cd5df79a264284"
 
+mitt@1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/mitt/-/mitt-1.1.0.tgz#22f0d57e2fedd39620a62bb41b7cdd93667d3c41"
+
 mkdirp-then@1.2.0:
   version "1.2.0"
   resolved "https://registry.npmjs.org/mkdirp-then/-/mkdirp-then-1.2.0.tgz#a492c879ca4d873f5ee45008f8f55fd0150de3c5"
@@ -3476,7 +3472,7 @@ nopt@~1.0.10:
   dependencies:
     abbrev "1"
 
-nopt@~3.0.1, nopt@~3.0.6:
+nopt@~3.0.6:
   version "3.0.6"
   resolved "https://registry.npmjs.org/nopt/-/nopt-3.0.6.tgz#c6465dbf08abcd4db359317f79ac68a646b28ff9"
   dependencies:
@@ -3499,20 +3495,6 @@ normalize-path@^2.0.0, normalize-path@^2.0.1:
   version "2.0.1"
   resolved "https://registry.npmjs.org/normalize-path/-/normalize-path-2.0.1.tgz#47886ac1662760d4261b7d979d241709d3ce3f7a"
 
-npmconf@^2.1.1:
-  version "2.1.2"
-  resolved "https://registry.npmjs.org/npmconf/-/npmconf-2.1.2.tgz#66606a4a736f1e77a059aa071a79c94ab781853a"
-  dependencies:
-    config-chain "~1.1.8"
-    inherits "~2.0.0"
-    ini "^1.2.0"
-    mkdirp "^0.5.0"
-    nopt "~3.0.1"
-    once "~1.3.0"
-    osenv "^0.1.0"
-    semver "2 || 3 || 4"
-    uid-number "0.0.5"
-
 npmlog@^4.0.1:
   version "4.0.2"
   resolved "https://registry.npmjs.org/npmlog/-/npmlog-4.0.2.tgz#d03950e0e78ce1527ba26d2a7592e9348ac3e75f"
@@ -3650,17 +3632,10 @@ os-locale@^1.4.0:
   dependencies:
     lcid "^1.0.0"
 
-os-tmpdir@^1.0.0, os-tmpdir@^1.0.1:
+os-tmpdir@^1.0.1:
   version "1.0.2"
   resolved "https://registry.npmjs.org/os-tmpdir/-/os-tmpdir-1.0.2.tgz#bbe67406c79aa85c5cfec766fe5734555dfa1274"
 
-osenv@^0.1.0:
-  version "0.1.4"
-  resolved "https://registry.npmjs.org/osenv/-/osenv-0.1.4.tgz#42fe6d5953df06c8064be6f176c3d05aaaa34644"
-  dependencies:
-    os-homedir "^1.0.0"
-    os-tmpdir "^1.0.0"
-
 p-limit@^1.1.0:
   version "1.1.0"
   resolved "https://registry.npmjs.org/p-limit/-/p-limit-1.1.0.tgz#b07ff2d9a5d88bec806035895a2bab66a27988bc"
@@ -3846,10 +3821,6 @@ promise@^7.1.1:
   dependencies:
     asap "~2.0.3"
 
-proto-list@~1.2.1:
-  version "1.2.4"
-  resolved "https://registry.npmjs.org/proto-list/-/proto-list-1.2.4.tgz#212d5bfe1318306a420f6402b8e26ff39647a849"
-
 prr@~0.0.0:
   version "0.0.0"
   resolved "https://registry.npmjs.org/prr/-/prr-0.0.0.tgz#1a84b85908325501411853d0081ee3fa86e2926a"
@@ -4152,7 +4123,7 @@ right-align@^0.1.1:
   dependencies:
     align-text "^0.1.1"
 
-rimraf@2, rimraf@^2.0.3, rimraf@^2.2.8, rimraf@^2.3.3, rimraf@^2.4.3, rimraf@^2.4.4, rimraf@^2.5.4:
+rimraf@2, rimraf@^2.2.8, rimraf@^2.3.3, rimraf@^2.4.3, rimraf@^2.4.4, rimraf@^2.5.4:
   version "2.6.1"
   resolved "https://registry.npmjs.org/rimraf/-/rimraf-2.6.1.tgz#c2338ec643df7a1b7fe5c54fa86f57428a55f33d"
   dependencies:
@@ -4204,10 +4175,6 @@ sax@^1.2.1:
   version "1.2.2"
   resolved "https://registry.npmjs.org/sax/-/sax-1.2.2.tgz#fd8631a23bc7826bef5d871bdb87378c95647828"
 
-"semver@2 || 3 || 4":
-  version "4.3.6"
-  resolved "https://registry.npmjs.org/semver/-/semver-4.3.6.tgz#300bc6e0e86374f7ba61068b5b1ecd57fc6532da"
-
 "semver@2 || 3 || 4 || 5", semver@^5.3.0, semver@~5.3.0:
   version "5.3.0"
   resolved "https://registry.npmjs.org/semver/-/semver-5.3.0.tgz#9b2ce5d3de02d17c6012ad326aa6b4d0cf54f94f"
@@ -4670,10 +4637,6 @@ uglify-to-browserify@~1.0.0:
   version "1.0.2"
   resolved "https://registry.npmjs.org/uglify-to-browserify/-/uglify-to-browserify-1.0.2.tgz#6e0924d6bda6b5afe349e39a6d632850a0f882b7"
 
-uid-number@0.0.5:
-  version "0.0.5"
-  resolved "https://registry.npmjs.org/uid-number/-/uid-number-0.0.5.tgz#5a3db23ef5dbd55b81fce0ec9a2ac6fccdebb81e"
-
 uid-number@~0.0.6:
   version "0.0.6"
   resolved "https://registry.npmjs.org/uid-number/-/uid-number-0.0.6.tgz#0ea10e8035e8eb5b8e4449f06da1c730663baa81"
@@ -4907,9 +4870,9 @@ write-file-atomic@^1.1.4:
     imurmurhash "^0.1.4"
     slide "^1.1.5"
 
-write-file-webpack-plugin@3.4.2:
+write-file-webpack-plugin@4.0.0:
-  version "3.4.2"
+  version "4.0.0"
-  resolved "https://registry.npmjs.org/write-file-webpack-plugin/-/write-file-webpack-plugin-3.4.2.tgz#16f7a1bbadb781fa661a2960e31c499f0a61b9bb"
+  resolved "https://registry.yarnpkg.com/write-file-webpack-plugin/-/write-file-webpack-plugin-4.0.0.tgz#2a7e4520fdcc02e687e8430d371bb41400b3cc0c"
   dependencies:
     chalk "^1.1.1"
     filesize "^3.2.1"