chore(docz-core): split socket from data server

Author: pedronauck

core/docz-core/src/bundler/server.ts

@@ -1,6 +1,7 @@
 import chalk from 'chalk'
 import logger from 'signale'
 import WebpackDevServer from 'webpack-dev-server'
+
 import { Configuration as Config } from 'webpack'
 import PrettyError from 'pretty-error'
 

core/docz-core/src/commands/build.ts

@@ -25,15 +25,16 @@ export const build = async (args: Arguments<any>) => {
 
   try {
     await Entries.writeApp(config, true)
-    await dataServer.init()
+    await dataServer.start()
 
     await run('onPreBuild', config)
     await bundler.build(bundlerConfig)
 
     await run('onPostBuild', config)
-    await dataServer.close()
+    dataServer.close()
   } catch (err) {
     pe.render(err)
     process.exit(1)
+    dataServer.close()
   }
 }

core/docz-core/src/commands/dev.ts

@@ -7,6 +7,7 @@ import PrettyError from 'pretty-error'
 
 import { Entries } from '../lib/Entries'
 import { DataServer } from '../lib/DataServer'
+import { Socket } from '../lib/Socket'
 import { parseConfig } from '../config/docz'
 import { onSignal } from '../utils/on-signal'
 import { bundler as webpack } from '../bundler'
@@ -18,6 +19,7 @@ export const dev = async (args: Arguments<any>) => {
   const config = await parseConfig(args)
   const bundler = webpack(config, env)
   const entries = new Entries(config)
+  const { websocketHost, websocketPort } = config
 
   const bundlerConfig = await bundler.mountConfig(env)
   const app = await bundler.createApp(bundlerConfig)
@@ -31,31 +33,35 @@ export const dev = async (args: Arguments<any>) => {
   }
 
   const server = await app.start()
-  const dataServer = new DataServer(
-    server,
-    config.websocketPort,
-    config.websocketHost
-  )
+  const dataServer = new DataServer()
+  const socket = new Socket(server, websocketHost, websocketPort)
 
   if (args.propsParser) dataServer.register([states.props(config)])
   dataServer.register([states.config(config), states.entries(entries, config)])
 
   try {
-    await dataServer.init()
-    await dataServer.listen()
+    await dataServer.start()
   } catch (err) {
     logger.fatal('Failed to process data server')
-    pe.render(err)
-    await dataServer.close()
+    logger.error(err)
+    dataServer.close()
     process.exit(1)
   }
 
+  socket.onConnection((_, emit) => {
+    const subscribe = dataServer.onStateChange(action => {
+      emit(action.type, action.payload)
+    })
+
+    return () => subscribe()
+  })
+
   onSignal(async () => {
-    await dataServer.close()
+    dataServer.close()
     server.close()
   })
 
   server.on('close', async () => {
-    await dataServer.close()
+    dataServer.close()
   })
 }

core/docz-core/src/lib/DataServer.ts

@@ -1,24 +1,7 @@
 import * as fs from 'fs-extra'
-import WS from 'ws'
 import { isFunction } from 'lodash/fp'
 
 import * as paths from '../config/paths'
-import { onSignal } from '../utils/on-signal'
-
-export type Send = (type: string, payload: any) => void
-export type On = (type: string) => Promise<any>
-
-const isSocketOpened = (socket: WS) => socket.readyState === WS.OPEN
-const sender = (socket?: WS) => (type: string, payload: any) => {
-  if (socket && isSocketOpened(socket)) {
-    socket.send(JSON.stringify({ type, payload }))
-  }
-}
-
-export interface Action {
-  type: string
-  payload: any
-}
 
 export interface Params {
   state: Record<string, any>
@@ -27,103 +10,74 @@ export interface Params {
 
 export interface State {
   id: string
-  init: (params: Params) => Promise<any>
-  update: (params: Params) => any
-  close: (params: Params) => any
+  start: (params: Params) => Promise<void>
+  close: () => void
+}
+
+export interface Action {
+  type: string
+  payload: any
 }
 
+export type Listener = (action: Action) => void
+
 export class DataServer {
-  private client?: WS.Server
   private states: Set<State>
-  private state: Record<string, any>
+  private state: Map<string, any>
+  private listeners: Set<Listener>
 
-  constructor(server?: any, port?: number, host?: string) {
+  constructor() {
     this.states = new Set()
-    this.state = {}
-
-    if (server) {
-      this.client = new WS.Server({
-        server,
-        port,
-        host,
-      })
-    }
+    this.state = new Map()
+    this.listeners = new Set<Listener>()
   }
 
   public register(states: State[]): DataServer {
     for (const state of states) this.states.add(state)
     return this
   }
 
-  public async init(): Promise<void> {
+  public async start(): Promise<void> {
+    const setState = (key: string, val: any) => this.setState(key, val)
+
     await Promise.all(
       Array.from(this.states).map(async state => {
-        if (!isFunction(state.init)) return
-        return state.init({
-          state: { ...this.state },
-          setState: this.setState(),
+        if (!isFunction(state.start)) return
+        return state.start({
+          setState,
+          state: this.mapToObject(this.state),
         })
       })
     )
-
-    this.updateStateFile()
   }
 
-  public async listen(): Promise<void> {
-    if (this.client) {
-      this.client.on('connection', socket => {
-        const close = this.handleConnection(socket)
-        const handleClose = async () => {
-          await close()
-          socket.terminate()
-        }
-
-        this.client!.on('close', handleClose)
-        onSignal(handleClose)
-      })
+  public close(): void {
+    for (const state of this.states) {
+      isFunction(state.close) && state.close()
     }
   }
 
-  public async close(): Promise<void> {
-    await Promise.all(
-      Array.from(this.states).map(
-        async state =>
-          isFunction(state.close) &&
-          state.close({
-            state: { ...this.state },
-            setState: this.setState(),
-          })
-      )
-    )
+  public onStateChange(listener: Listener): () => void {
+    this.listeners.add(listener)
+    return () => this.listeners.clear()
   }
 
-  private handleConnection(socket: WS): () => void {
-    const states = Array.from(this.states).map(
-      async state =>
-        isFunction(state.update) &&
-        state.update({
-          state: this.state,
-          setState: this.setState(socket),
-        })
-    )
-
-    return async () => {
-      const fns = await Promise.all(states.filter(Boolean))
-      for (const fn of fns) isFunction(fn) && fn()
-    }
+  private setState(key: string, val: any): void {
+    this.state.set(key, val)
+    this.writeDbFile()
+    this.listeners.forEach(listener => {
+      listener({ type: `state.${key}`, payload: val })
+    })
   }
 
-  private setState(socket?: WS): (key: string, val: any) => void {
-    const send = sender(socket)
-
-    return (key: string, val: any): void => {
-      this.state[key] = val
-      send(`state.${key}`, val)
-      this.updateStateFile()
-    }
+  private async writeDbFile(): Promise<void> {
+    fs.outputJSONSync(paths.db, this.mapToObject(this.state), { spaces: 2 })
   }
 
-  private async updateStateFile(): Promise<void> {
-    await fs.outputJSON(paths.db, this.state, { spaces: 2 })
+  private mapToObject<T>(map: Map<string, any>): T {
+    return Array.from(map.entries()).reduce(
+      (obj, [key, val]) => ({ ...obj, [key]: val }),
+      {} as T
+    )
   }
 }

core/docz-core/src/lib/Socket.ts

@@ -0,0 +1,43 @@
+import WS from 'ws'
+import { onSignal } from '../utils/on-signal'
+
+export type Send = (type: string, payload: any) => void
+export type On = (type: string) => Promise<any>
+
+const isSocketOpened = (socket: WS) => socket.readyState === WS.OPEN
+const sender = (socket?: WS) => (type: string, payload: any) => {
+  if (socket && isSocketOpened(socket)) {
+    socket.send(JSON.stringify({ type, payload }))
+  }
+}
+
+export class Socket {
+  private client?: WS.Server
+
+  constructor(server?: any, host?: string, port?: number) {
+    if (server) {
+      this.client = new WS.Server({
+        server,
+        host,
+        port,
+      })
+    }
+  }
+
+  public onConnection(listener: (socket: WS, emit: Send) => () => void): void {
+    if (!this.client) return
+
+    this.client.on('connection', socket => {
+      const emit = sender(socket)
+      const subs = listener(socket, emit)
+
+      const handleClose = async () => {
+        subs()
+        socket.terminate()
+      }
+
+      this.client!.on('close', handleClose)
+      onSignal(handleClose)
+    })
+  }
+}

core/docz-core/src/states/config.ts

@@ -56,17 +56,17 @@ export const state = (config: Config): State => {
 
   return {
     id: 'config',
-    init: updateConfig(config),
-    close: () => watcher.close(),
-    update: async params => {
+    start: async params => {
       const update = updateConfig(config)
       const fn = async () => update(params)
 
+      await update(params)
       watcher.on('add', fn)
       watcher.on('change', fn)
       watcher.on('unlink', fn)
-
-      return () => watcher.close()
+    },
+    close: () => {
+      watcher.close()
     },
   }
 }

core/docz-core/src/states/entries.ts

@@ -41,20 +41,20 @@ export const state = (entries: Entries, config: Config): State => {
 
   return {
     id: 'entries',
-    init: updateEntries(entries),
-    close: () => watcher.close(),
-    update: async params => {
+    start: async params => {
       const update = updateEntries(entries)
 
+      watcher.on('add', async () => update(params))
       watcher.on('change', async () => update(params))
       watcher.on('unlink', async () => update(params))
       watcher.on('raw', async (event: string, path: string, details: any) => {
         if (details.event === 'moved' && details.type === 'directory') {
           await update(params)
         }
       })
-
-      return () => watcher.close()
+    },
+    close: () => {
+      watcher.close()
     },
   }
 }

core/docz-core/src/states/props.ts

@@ -33,7 +33,7 @@ const add = (config: Config) => (p: Params) => async (filepath: string) => {
   }
 }
 
-const remove = (config: Config) => (p: Params) => async (filepath: string) =>
+const remove = (p: Params) => async (filepath: string) =>
   p.setState('props', omit(filepath, get('state.props', p)))
 
 export const state = (config: Config): State => {
@@ -48,17 +48,17 @@ export const state = (config: Config): State => {
 
   return {
     id: 'props',
-    init: initial(config),
-    close: () => watcher.close(),
-    update: async params => {
+    start: async params => {
       const addFilepath = add(config)
-      const removeFilepath = remove(config)
+      const addInitial = initial(config)
 
+      await addInitial(params)
       watcher.on('add', addFilepath(params))
       watcher.on('change', addFilepath(params))
-      watcher.on('unlink', removeFilepath(params))
-
-      return () => watcher.close()
+      watcher.on('unlink', remove(params))
+    },
+    close: () => {
+      watcher.close()
     },
   }
 }