refactor(realtime): extract user event "cursor" related

1. move "cursor focus", "cursor activity", "cursor blur" event handler to SocketClient
2. add test case for that

Signed-off-by: BoHong Li <a60814billy@gmail.com>

Author: a60814billy

lib/realtime.js

@@ -763,22 +763,65 @@ class SocketClient {
     this.socket.on('refresh', this.refreshEventHandler.bind(this))
     // received user status
     this.socket.on('user status', this.userStatusEventHandler.bind(this))
-
     // when a new client disconnect
     this.socket.on('disconnect', this.disconnectEventHandler.bind(this))
+    // received cursor focus
+    this.socket.on('cursor focus', this.cursorFocusEventHandler.bind(this))
+    // received cursor activity
+    this.socket.on('cursor activity', this.cursorActivityEventHandler.bind(this))
+    // received cursor blur
+    this.socket.on('cursor blur', this.cursorBlurEventHandlder.bind(this))
+  }
+
+  isNoteAndUserExists () {
+    const note = getNoteFromNotePool(this.socket.noteId)
+    const user = getUserFromUserPool(this.socket.id)
+    return note && user
+  }
 
+  getCurrentUser () {
+    return getUserFromUserPool(this.socket.id)
+  }
+
+  getNoteChannel () {
+    return this.socket.broadcast.to(this.socket.noteId)
+  }
+
+  cursorFocusEventHandler (data) {
+    if (!this.isNoteAndUserExists()) return
+    const user = this.getCurrentUser()
+    user.cursor = data
+    const out = buildUserOutData(user)
+    this.getNoteChannel().emit('cursor focus', out)
+  }
+
+  cursorActivityEventHandler (data) {
+    if (!this.isNoteAndUserExists()) return
+    const user = this.getCurrentUser()
+    user.cursor = data
+    const out = buildUserOutData(user)
+    this.getNoteChannel().emit('cursor activity', out)
+  }
+
+  cursorBlurEventHandlder () {
+    if (!this.isNoteAndUserExists()) return
+    const user = this.getCurrentUser()
+    user.cursor = null
+    this.getNoteChannel().emit('cursor blur', {
+      id: this.socket.id
+    })
   }
 
   refreshEventHandler () {
     exports.emitRefresh(this.socket)
   }
 
   userStatusEventHandler (data) {
-    const noteId = this.socket.noteId
-    const user = getUserFromUserPool(this.socket.id)
-    if (!noteId || !getNoteFromNotePool(noteId) || !user) return
-
-    if (config.debug) { logger.info('SERVER received [' + noteId + '] user status from [' + this.socket.id + ']: ' + JSON.stringify(data)) }
+    if (!this.isNoteAndUserExists()) return
+    const user = this.getCurrentUser()
+    if (config.debug) {
+      logger.info('SERVER received [' + this.socket.noteId + '] user status from [' + this.socket.id + ']: ' + JSON.stringify(data))
+    }
     if (data) {
       user.idle = data.idle
       user.type = data.type
@@ -946,7 +989,9 @@ function connection (socket) {
     var users = []
     Object.keys(notes[noteId].users).forEach(function (key) {
       var user = notes[noteId].users[key]
-      if (user) { users.push(buildUserOutData(user)) }
+      if (user) {
+        users.push(buildUserOutData(user))
+      }
     })
     var out = {
       users: users
@@ -961,38 +1006,6 @@ function connection (socket) {
       minimumCompatibleVersion: config.minimumCompatibleVersion
     })
   })
-
-  // received cursor focus
-  socket.on('cursor focus', function (data) {
-    var noteId = socket.noteId
-    var user = users[socket.id]
-    if (!noteId || !notes[noteId] || !user) return
-    user.cursor = data
-    var out = buildUserOutData(user)
-    socket.broadcast.to(noteId).emit('cursor focus', out)
-  })
-
-  // received cursor activity
-  socket.on('cursor activity', function (data) {
-    var noteId = socket.noteId
-    var user = users[socket.id]
-    if (!noteId || !notes[noteId] || !user) return
-    user.cursor = data
-    var out = buildUserOutData(user)
-    socket.broadcast.to(noteId).emit('cursor activity', out)
-  })
-
-  // received cursor blur
-  socket.on('cursor blur', function () {
-    var noteId = socket.noteId
-    var user = users[socket.id]
-    if (!noteId || !notes[noteId] || !user) return
-    user.cursor = null
-    var out = {
-      id: socket.id
-    }
-    socket.broadcast.to(noteId).emit('cursor blur', out)
-  })
 }
 
 exports = module.exports = realtime

test/realtime.test.js

@@ -7,13 +7,26 @@ const assert = require('assert')
 const sinon = require('sinon')
 
 function makeMockSocket (headers, query) {
+  const broadCastChannelCache = {}
   return {
     id: Math.round(Math.random() * 10000),
     handshake: {
       headers: Object.assign({}, headers),
       query: Object.assign({}, query)
     },
-    on: sinon.fake()
+    on: sinon.fake(),
+    broadCastChannelCache: {},
+    broadcast: {
+      to: (channel) => {
+        if (!broadCastChannelCache[channel]) {
+          broadCastChannelCache[channel] = {
+            channel: channel,
+            emit: sinon.fake()
+          }
+        }
+        return broadCastChannelCache[channel]
+      }
+    }
   }
 }
 
@@ -553,9 +566,48 @@ describe('realtime', function () {
         disconnectFunc()
         assert(disconnectStub.called === false)
       })
+    })
+
+    ;['cursor focus', 'cursor activity', 'cursor blur'].forEach( (event) => {
+      describe(event, function () {
+        let cursorFocusFunc
+
+        const cursorData = {
+          cursor: 10
+        }
+
+        beforeEach(() => {
+          cursorFocusFunc = eventFuncMap.get(event)
+          realtime.notes[noteId] = {}
+        })
 
+        it('should broadcast to all client', () => {
+          cursorFocusFunc(cursorData)
+          const broadChannelEmitFake = clientSocket.broadcast.to(noteId).emit
+          assert(broadChannelEmitFake.calledOnce)
+          assert(broadChannelEmitFake.lastCall.args[0] === event)
+          if (event === 'cursor blur') {
+            assert(broadChannelEmitFake.lastCall.args[1].id === clientSocket.id)
+          } else {
+            assert.deepStrictEqual(broadChannelEmitFake.lastCall.args[1].cursor, cursorData)
+          }
+        })
+
+        it('should not broadcast when note not exists', () => {
+          delete realtime.notes[noteId]
+          cursorFocusFunc(cursorData)
+          const broadChannelEmitFake = clientSocket.broadcast.to(noteId).emit
+          assert(broadChannelEmitFake.called === false)
+        })
+
+        it('should not broadcast when user not exists', () => {
+          delete realtime.users[clientSocket.id]
+          cursorFocusFunc(cursorData)
+          const broadChannelEmitFake = clientSocket.broadcast.to(noteId).emit
+          assert(broadChannelEmitFake.called === false)
+        })
+      })
     })
 
   })
-
 })