Sequelize Class Generator

Installation

npm add -D @bitbean/sequelize-classgen

See demo/README.md to try the working demo.

Usage

1. Copy the example.sequelize-classgen.cjs file into your project.
2. Rename it to .sequelize-classgen.cjs.
3. Edit the file to change the directory option and other options. Intellisense/Autocomplete should be helpful. You can also change the getDbConfig function in this file to use something other than an ENV var to get the basic db config.
4. Add a script to your package.json:

"scripts": {
  "generate-models": "sequelize-classgen",
}

5. npm run generate-models The files should be in whatever directory you specified in the config.

If you want to pass a custom config you can do:

"scripts": {
  "generate-models": "sequelize-classgen ./my-config.cjs",
}

or from the command-line, e.g. npm run generate-models ./my-config.cjs

Differences with sequelize-auto

• Generated TypeScript models have declare before class properties.
• Removed the :! after associated class properties (TypeScript).
• Added options initModelsDefault, noSchemas and tsEsm. See Advanced Configuration for details.
• Added a new static include function to each model to give intellisense when using the include: [...] option in your queries. See Model Additions.
• Fixed TypeScript models call to MyModel.init({...}) by always generating the created_at, updated_at fields even if paranoid is true.
• Only has a single (optional) CLI arg for a single .js config file. The default config file name is .sequelize-classgen.cjs.

Advanced Configuration

Basic options are documented with sequelize-auto and sequelize. These advanced options are part of sequelize-classgen.

initModelsDefault option

The generated initModels code has been changed radically to simplify the structure of the file and to make exporting models cleaner. To that end, we prefer to export default function initModels() {} instead of export function initModels() {}. We also export * from "./MyModel.js for each model and that way your own src/code/db/index.ts file can just do export * from "./init-models"; which won't export the default initModels (unless initModelsDefault is false).

Defaults to true.

noSchemas option / TypeBox Schemas

This defaults to false since the mui-fastify-template project where this code originated uses TypeBox to create JSON Schema objects and their associated TS types for use with the OpenAPI/Swagger schema that gets registered with Fastify.

The schemas we generate are added as MyModelName.Row which is a TS type AND a live JS object which represents the JSON Schema for the base row. Using TypeBox you can build other JSON Schemas and types that exclude or add properties to the base Row schema/type.

These schemas can be used in any situation where you need a JSON Schema object and a corresponding TypeScript type. It would be nice to use with Express too. See examples in mui-fastify-template/backend/api-server/src/db/main/....

This is option is set to false in the example config, for most other projects.

tsEsm option for ESM/Node modules

For Node packages that have "type":"module" in the package.json, TypeScript code must only use import statements with *.js file extension. For example, your TS code will have to do:

import { helper } from "./helper.js"; // <-- EVEN if the source is ./helper.ts

This is because the TypeScript team has vowed to never re-write import statements.

To handle this, the tsEsm option was added. It defaults to true. The example.sequelize-classgen.cjs file sets it to false so that the example is ready for use in most projects which are not using ESM yet...

The ESM rules are also why the .sequelize-classgen.cjs file uses the .cjs file extension. Otherwise, in Node packages with "type": "module", you'll get errors if it's named .js and if the file uses require() or doesn't follow other ESM rules. The .cjs extension should work everywhere, even non-ESM packages.

Model Additions

Aside from the TypeBox schemas we also add a TypeScript namespace to extend the Model class with some other things:

static include function

A new static include function is generated for each model to give intellisense when using the include: [...] option in your queries. For example:

const user = await User.findOne({
  where: { email: body.email.trim().toLowerCase() },
  include: User.include("parent_address", "parent_schools", "user_roles"),
});

or

const item = await GiftOrder.unscoped().findByPk(id, {
  include: GiftOrder.include(
    // 1st include, just by name of association
    "gift_items",
    // 2nd include with a specific scope to allow fetching timestamp fields...
    {
      as: "gift_transactions",
      model: GiftTransaction.unscoped(),
    },
  ),
});