Mongoose post update middleware not working - node.js

Question

I am use "mongoose": "^4.1.2". I have try to update a matchRate field when after a document being updated. But it doesn't work either not throw an any errors.
Here is code:
list.model.js
'use strict';
var mongoose = require('bluebird').promisifyAll(require('mongoose'));
import { Schema } from 'mongoose';
var ListSchema = new Schema({
name: { type: String, required: true },
user: { type: Schema.Types.ObjectId, ref: 'User', required: true },
emails: [],
emailColRef: String,
matchCount: Number,
totalCount: Number,
matchRate: Number,
state: {
type: String,
enum: ['pending', 'complete', 'invalid']
},
user: {
type: mongoose.Schema.Types.ObjectId,
ref: 'User'
},
default: {
type: Boolean,
default: false
}
});
ListSchema
.virtual('count')
.get(() => this.emails.length);
ListSchema
.post('update', function() {
// this.update({},{ $set: { matchRate: this.matchCount / this.totalCount } });//Not working
//////-------------OR---------------//////
// this.matchRate=this.matchCount / this.totalCount;//Not working
console.log(this.matchCount);//undefined
console.log(this.totalCount);//undefined
console.log(this.matchRate);//undefined
});
export default mongoose.model('List', ListSchema);
list.controller.js
.....
.....
.....
var newList = {};
newList.name = name;
newList.emails = emails;
newList.emailColRef = emailColRef;
newList.state = status;
newList.matchCount = matchCount;
newList.totalCount = totalCount;
var query = { name: req.body.name };
List.update(query, newList, function(err, doc) {
// index(req, res);
if (err) {
console.log("Error in list update ", err)
return;
}
fs.unlink(req.file.path, function(err) {
if (err) {
console.log("Error in removing file", err)
return;
}
});
console.log('Update list with match status');
});