How can I subclass Model and properly add a static method? - node.js

Question

I'm learning how to use Sequelize as the ORM for a small web app. Each record in the (MySQL) database has a uuid field. I want to add a findByUuid static method to all of the models. Here's my attempt:
class Base extends Model {
static findByUuid = async (uuid) => {
return await super.findOne({ where: {uuid: uuid} });
}
}
class List extends Base {
}
List.init({
uuid: {
type: DataTypes.UUID,
allowNull: false,
defaultValue: Sequelize.UUIDV4
},
name: {
type: DataTypes.STRING,
allowNull: false
}
}, {
sequelize,
nodelName: 'List',
indexes: [
{ fields: ['name'] },
{ fields: ['uuid'] }
]
});
(async () => {
await sequelize.sync({ force: true });
const list = List.build({name: 'New List'});
await list.save();
console.log('id: ' + list.id);
console.log('uuid: ' + list.uuid);
const direct_retrieved = await List.findOne({ where: {uuid: list.uuid} });
console.log('direct name: ' + direct_retrieved.name);
const retrieved = await List.findByUuid(list.uuid);
console.log('static retrieved: ' + retrieved.name);
})();
And here's the output (excluding the echoed SQL commands):
id: 1
uuid: 371971dd-a4d9-43aa-ac10-afe3c10154b0
direct name: New List
/Users/chuck/Projects/app/node_modules/sequelize/lib/model.js:1692
this.warnOnInvalidOptions(options, Object.keys(this.rawAttributes));
^
TypeError: Cannot convert undefined or null to object
at Function.keys (<anonymous>)
at Function.findAll (/Users/chuck/Projects/app/node_modules/sequelize/lib/model.js:1692:47)
at Function.findOne (/Users/chuck/Projects/app/node_modules/sequelize/lib/model.js:1917:23)
at Function.findByUuid (/Users/chuck/Projects/app/models/models.js:7:36)
at /Users/chuck/Projects/app/models/models.js:181:34
at processTicksAndRejections (node:internal/process/task_queues:93:5)
So directly working with findOne is working, but trying to do so within the static method causes the error, and I have not been able to figure out why.
I think the problem is that the Base class has no knowledge of a uuid field. If I put the static method into the List class, it works properly. So the only solution I have so far is to repeat that code for every actual table since I don't (yet) see a way to define the uuid field in the Base class (which would be preferable anyway.

Answer 1

It turns out that I needed to override init to let Base know about the uuid field. Here's the working solution.
const { Sequelize, DataTypes, Model } = require('sequelize');
const sequelize = require('./helpers/sequelize');
class Base extends Model {
static findByUuid = async (uuid) => {
return await super.findOne({ where: {uuid: uuid} });
}
static init = (attributes, options = {}) => {
attributes.uuid = {
type: DataTypes.UUID,
allowNull: false,
defaultValue: Sequelize.UUIDV4
};
options.indexes.push({ fields: ['uuid'] });
super.init(attributes, options);
}
}
class List extends Base {
}
List.init({
name: {
type: DataTypes.STRING,
allowNull: false
}
}, {
sequelize,
modelName: 'List',
indexes: [
{ fields: ['name'] }
]
});
(async () => {
await sequelize.sync({ force: true });
const list = List.build({name: 'New List'});
await list.save();
console.log('id: ' + list.id);
console.log('uuid: ' + list.uuid);
const direct_retrieved = await List.findOne({ where: {uuid: list.uuid} });
console.log('direct: ' + direct_retrieved.name);
const retrieved = await List.findByUuid(list.uuid);
console.log('static: ' + retrieved.name);
})();