Sequelize - Cannot read property 'list' of undefined - node.js

Question

Im just learn to use sequelize for my node.js project. For summary my project is ExpressJS+Typescript with Sequelize as ORM and Webpack as module bundler.
Below is my project structure.
src
-router
-server
--config
config.json
--controllers
index.ts
User.ts
--migrations
--models
index.js
user.js
--seeders
App.ts
index.ts
(sorry can not post picture yet, new user to stackoverflow)
I have build some simple router '/user' and expect it should call the user controller and call sequelize method findAll() from my models module, but the result is its error says Cannot read property 'list' of undefined. Below is my code:
models/index.js
const fs = require('fs');
const path = require('path');
const Sequelize = require('sequelize');
const basename = path.basename(module.filename);
const env = process.env.NODE_ENV || 'development';
const config = require(`${__dirname}/../config/config.json`)[env];
const db = {};
let sequelize;
if (config.use_env_variable) {
sequelize = new Sequelize(process.env[config.use_env_variable]);
} else {
sequelize = new Sequelize(
config.database, config.username, config.password, config
);
}
fs
.readdirSync(__dirname)
.filter(file =>
(file.indexOf('.') !== 0) &&
(file !== basename) &&
(file.slice(-3) === '.js'))
.forEach(file => {
const model = sequelize.import(path.join(__dirname, file));
db[model.name] = model;
});
Object.keys(db).forEach(modelName => {
if (db[modelName].associate) {
db[modelName].associate(db);
}
});
db.sequelize = sequelize;
db.Sequelize = Sequelize;
export default db;
models/user.js
export default function(sequelize, DataTypes) {
var user = sequelize.define('user', {
username: DataTypes.STRING,
name: DataTypes.STRING,
email: DataTypes.STRING,
password: DataTypes.STRING,
phone: DataTypes.STRING,
wallet: DataTypes.DECIMAL
}, {
classMethods: {
associate: function(models) {
// associations can be defined here
user.hasMany(models.top_up);
}
}
});
return user;
};
controllers/User.ts
let user = require('../models').user;
export default {
list(req, res) {
return user
.findAll()
.then(topUp => res.status(200).send(topUp))
.catch(error => res.status(400).send(error));
}
};
controllers/Index.ts
import users from './User'
export default {
users
}
router/router.ts
import * as express from 'express';
const userController = require('../server/controllers').users;
// Init express router
let router = express.Router();
// Setting API URL
router.get('/', (req, res, next) => {
res.json({
message: 'Hello World!'
});
});
router.get('/about',(req, res, next) => {
res.send('<p>This is about about</p>');
});
router.get('/user', userController.list());
export default router
Fyi, all of my project configuration for start express server, typescript compile and webpack bundle is fine already, and the other route for '/' and '/about' is work fine. I know there is something I'm missing, im still new to sequelize, thanks for help.

Answer 1

TL;DR: The server/controllers/index.ts does not export a binding named users, itexports a binding named default.
You are importing the controllers/Index.ts module using the require function. In a CommonJS environment, this imports the entire module.exports object. As currently transpiled by TypeScript, every named export of the required module is exposed as a property of the import.
An export default clause implies an export named default. As per the ES Module specification, there is a shorthand for importing the default export of a module. That shorthand is
import userController from '../server/controllers';
On the other hand, the syntax
import userController = require('../server/controllers');
or
const userController = require('../server/controllers'); // (or let or var)
imports an object with a property corresponding to each export. In this case it has the shape
{ default }
So if you use require, you need to write
import userController = require('../server/controllers').default;
or
import userController from '../server/controllers';
All ES Module style exports are named, including the default which is named default.
To illustrate this, consider the following, more verbose but semantically identical form
import {default as userController} from '../server/controllers';
If you would prefer to stick with CommonJS style exports, eschewing ES Modules when working in NodeJS, the idiomatic way to export a single object as the entire module (the object returned by require)
You may write
// ../server/controllers/index.ts
export = {
list(req, res) {
return user
.findAll()
.then(topUp => res.status(200).send(topUp))
.catch(error => res.status(400).send(error));
}
};
Personally, I would stick with what you have and write
import userController from '../server/controllers';