From 959a2eb46f9c6303f6afdf8ab6b5640295a91f4a Mon Sep 17 00:00:00 2001
From: Kata <git@kat.cafe>
Date: Mon, 25 Feb 2019 00:47:08 -0600
Subject: [PATCH] backend: router hot-reloading

---
 Roleypoly.js | 40 +++++++++++++++++++++++++++++++++-------
 api/index.js |  8 ++++++--
 index.js     | 11 +++--------
 package.json | 14 +++++++++++---
 4 files changed, 53 insertions(+), 20 deletions(-)

diff --git a/Roleypoly.js b/Roleypoly.js
index bf067ac..61b8f71 100644
--- a/Roleypoly.js
+++ b/Roleypoly.js
@@ -3,16 +3,17 @@ const Sequelize = require('sequelize')
 const fetchModels = require('./models')
 const fetchApis = require('./api')
 const Next = require('next')
-
+const betterRouter = require('koa-better-router')
 
 class Roleypoly {
-  constructor (router, io, app) {
-    this.router = router
+  constructor (io, app) {
     this.io = io
     this.ctx = {}
 
     this.ctx.config = {
-      appUrl: process.env.APP_URL
+      appUrl: process.env.APP_URL,
+      dev: process.env.NODE_ENV !== 'production',
+      hotReload: process.env.NO_HOT_RELOAD !== '1'
     }
 
     this.ctx.io = io
@@ -52,10 +53,11 @@ class Roleypoly {
     this.ctx.P = new (require('./services/presentation'))(this.ctx)
   }
 
-  async mountRoutes () {
+  async loadRoutes (forceClear = false) {
     await this.ctx.ui.prepare()
 
-    fetchApis(this.router, this.ctx)
+    this.router = betterRouter().loadMethods()
+    fetchApis(this.router, this.ctx, { forceClear })
 
     // after routing, add the * for ui handler
     this.router.get('*', async ctx => {
@@ -63,7 +65,31 @@ class Roleypoly {
       ctx.respond = false
     })
 
-    this.__app.use(this.router.middleware())
+    return this.router.middleware()
+  }
+
+  async mountRoutes () {
+    let mw = await this.loadRoutes()
+
+    if (this.ctx.config.dev && this.ctx.config.hotReload) {
+      // hot-reloading system
+      log.info('API hot-reloading is active.')
+      const chokidar = require('chokidar')
+      let hotMiddleware = mw
+
+      this.__apiWatcher = chokidar.watch('api/**')
+      this.__apiWatcher.on('all', async (path) => {
+        log.info('reloading APIs...', path)
+        hotMiddleware = await this.loadRoutes(true)
+      })
+
+      // custom passthrough so we use a specially scoped middleware.
+      mw = (ctx, next) => {
+        return hotMiddleware(ctx, next)
+      }
+    }
+
+    this.__app.use(mw)
   }
 }
 
diff --git a/api/index.js b/api/index.js
index ca717b0..797a74a 100644
--- a/api/index.js
+++ b/api/index.js
@@ -3,7 +3,7 @@ const glob = require('glob')
 
 const PROD = process.env.NODE_ENV === 'production'
 
-module.exports = async (router, ctx) => {
+module.exports = async (router, ctx, { forceClear = false } = {}) => {
   const apis = glob.sync(`./api/**/!(index).js`)
   log.debug('found apis', apis)
 
@@ -14,7 +14,11 @@ module.exports = async (router, ctx) => {
     }
     log.debug(`mounting ${a}`)
     try {
-      require(a.replace('api/', ''))(router, ctx)
+      const pathname = a.replace('api/', '')
+      if (forceClear) {
+        delete require.cache[require.resolve(pathname)]
+      }
+      require(pathname)(router, ctx)
     } catch (e) {
       log.error(`couldn't mount ${a}`, e)
     }
diff --git a/index.js b/index.js
index 676bef8..37e1228 100644
--- a/index.js
+++ b/index.js
@@ -1,13 +1,10 @@
-require('dotenv').config({silent: true})
+require('dotenv').config({ silent: true })
 const log = new (require('./logger'))('index')
 
 const http = require('http')
 const Koa = require('koa')
 const app = new Koa()
 const _io = require('socket.io')
-const fs = require('fs')
-const path = require('path')
-const router = require('koa-better-router')().loadMethods()
 const Roleypoly = require('./Roleypoly')
 const ksuid = require('ksuid')
 
@@ -20,7 +17,7 @@ Array.prototype.areduce = async function (predicate, acc = []) { // eslint-disab
   return acc
 }
 
-Array.prototype.filterNot = Array.prototype.filterNot || function (predicate) {
+Array.prototype.filterNot = Array.prototype.filterNot || function (predicate) { // eslint-disable-line
   return this.filter(v => !predicate(v))
 }
 
@@ -28,9 +25,7 @@ Array.prototype.filterNot = Array.prototype.filterNot || function (predicate) {
 const server = http.createServer(app.callback())
 const io = _io(server, { transports: ['websocket'], path: '/api/socket.io' })
 
-
-
-const M = new Roleypoly(router, io, app) // eslint-disable-line no-unused-vars
+const M = new Roleypoly(io, app) // eslint-disable-line no-unused-vars
 
 app.keys = [ process.env.APP_KEY ]
 
diff --git a/package.json b/package.json
index 5192063..5f7c6e0 100644
--- a/package.json
+++ b/package.json
@@ -3,12 +3,13 @@
   "version": "2.0.0",
   "main": "index.js",
   "scripts": {
-    "start": "pm2 start index.js",
-    "dev": "pm2 start index.js --watch",
-    "build": "next build"
+    "start": "node index.js",
+    "dev": "node index.js",
+    "build": "next build ui"
   },
   "dependencies": {
     "@discordjs/uws": "^11.149.1",
+    "@primer/components": "^10.0.1",
     "chalk": "^2.4.2",
     "discord.js": "^11.4.2",
     "dotenv": "^6.2.0",
@@ -32,5 +33,12 @@
     "socket.io": "^2.2.0",
     "superagent": "^4.1.0",
     "uuid": "^3.3.2"
+  },
+  "devDependencies": {
+    "babel-eslint": "^10.0.1",
+    "babel-plugin-transform-flow-strip-types": "^6.22.0",
+    "chokidar": "^2.1.2",
+    "flow-type": "^1.0.1",
+    "standard": "^12.0.1"
   }
 }