Support automatic model configuration with webpack about express-example

[mexx]

I've got Webpack to include the models into the bundle, here my index.js:

import Sequelize from 'sequelize'
const env = process.env.NODE_ENV || 'development';
const config = require(`${__dirname}/../config/config.js`)[env];
const db = {};

let sequelize;
if (config.use_env_variable) {
  sequelize = new Sequelize(process.env[config.use_env_variable], config);
} else {
  sequelize = new Sequelize(config.database, config.username, config.password, config);
}

const context = require.context('.', true, /^\.\/(?!index\.js).*\.js$/, 'sync')
context.keys().map(context).forEach(module => {
  const sequelizeModel = module(sequelize, Sequelize);
  db[sequelizeModel.name] = sequelizeModel;
})

Object.keys(db).forEach(modelName => {
  if (db[modelName].associate) {
    db[modelName].associate(db);
  }
});

db.sequelize = sequelize;
db.Sequelize = Sequelize;

export default db;

[astiag]

@incompletude you can do like this:

context.keys().map(context).forEach(({ default: module }) => {...

[AwolDes]

@papb I'm still running into trouble with associations on lambda using webpack & sequelize. I've submitted an issue here with a PoC repo: sequelize/sequelize#12874

Unsure if it's the way my models are created/associated, or something a bit more sinister. I've tried the various different methods so far and no luck.

[zainzafar]

I'm having the same issue. Were you able to figure this out?

[Aditya94A]

@zainzafar Sadly, no :(

I eventually gave up on using webpack/babel completely since node v8 is like 99% ES6 compliant already and so we no longer really need babel for the most part.

[aguynamedben]

Thanks for working on Sequelize. I like it a lot and mean to provide constructive feedback.

I'm having the same problem. This also applies to Umzug migrations. From what I've learned, some Node.js-centric dependencies expect to be able to crawl a directory and dynamically require() things at runtime (i.e. Umzug migrations/ directory, models/index.js in Sequelize) are a world of pain in a Webpack/Babel/Electron world.

For migrations, I just gave up and just built my own small migration framework that doesn't have dynamic require()'s and following your simple but annoying strategy of importing each migration.

Once I got past that, I hit the same exact thing with Sequelize models being dynamically imported. I'll probably just use the workaround for now so I can use models.

It would be nice if Sequelize and Umzug were a little less aggressive about assuming things about the environment they operate in. require(), import, import() all seem to be a mess between various JavaScript transpilers and environments. "Use pure Node.js 10.x" is a fine solution, but all my other code is using Webpack, so it's really fragments my codebase into 2 styles (some Webpack/Babel, some pure Node.js, can't import between).

I know "it's Webpack's fault", but there's still not a great solution. With Umzug, I almost got customResolver working with babel/ES6, until I realized that webpack-dev-server screws with module, making this method not work in a webpack-dev-server environment (module.constructor is undefined in webpack-dev-server environment, and I couldn't figure out a workaround to convert my transpiled code into an object).

[incompletude]

I've got Webpack to include the models into the bundle, here my index.js:

import Sequelize from 'sequelize'
const env = process.env.NODE_ENV || 'development';
const config = require(`${__dirname}/../config/config.js`)[env];
const db = {};

let sequelize;
if (config.use_env_variable) {
  sequelize = new Sequelize(process.env[config.use_env_variable], config);
} else {
  sequelize = new Sequelize(config.database, config.username, config.password, config);
}

const context = require.context('.', true, /^\.\/(?!index\.js).*\.js$/, 'sync')
context.keys().map(context).forEach(module => {
  const sequelizeModel = module(sequelize, Sequelize);
  db[sequelizeModel.name] = sequelizeModel;
})

Object.keys(db).forEach(modelName => {
  if (db[modelName].associate) {
    db[modelName].associate(db);
  }
});

db.sequelize = sequelize;
db.Sequelize = Sequelize;

export default db;

This does not work for me. At const model = module(sequelize, Sequelize) I get an error stating module is not a function.

[papb]

Hello everyone! Sorry to take long to address this issue.

It would be nice if Sequelize and Umzug were a little less aggressive about assuming things about the environment they operate in.

I agree.

I have replaced the previous example in this repository with a new, modern example that no longer uses sequelize.import nor reads the filesystem to detect modules. Things should just work now.

Let me know if anyone has further questions, thank you!!

[papb]

Hi @AwolDes, I've just replied you in that issue 😀

@ everyone else: please also look at sequelize/sequelize#13169 about using Sequelize with Webpack.