Typescript example of M:N relationship (belongsToMany) with through table attributes

Issue Description

Examples of using Typescript with many-to-many relationships (i.e. belongsToMany <-> belongsToMany)

What was unclear/insufficient/not covered in the documentation

Only simple relationship examples exist: i.e hasMany

Additional context

I’ve looked through the type definitions and tests and I’m coming up empty-handed.

Simple example:

class Account extends Model { }

class User extends Model {
  public addAccount!: ????
}

User.belongsToMany(Account, { through: AccountUser });
Account.belongsToMany(User, { through: AccountUser });

userInst.addAccount(accountInst, { through: { role: 'owner' } })

How do I declare the addAccount method of class User? My through table (AccountUser) has a single attribute (role). I’ve looked through the code (i.e. associations/belongs-to-many.d.ts) but I’m stumped. It appears that BelongsToManyAddAssociationMixin takes 3 arguments but when I express something like:

public addAccount!: BelongsToManyAddAssociationMixin<Account, string, { role: string }>;

it complains with Generic type 'BelongsToManyAddAssociationMixin' requires 2 type argument(s)

Some help and guidance would be greatly appreciated. I’d be happy to contribute to the Typescript documentation page to cover this use case.

Is this issue dialect-specific?

• No. This issue is relevant to Sequelize as a whole.
• Yes. This issue only applies to the following dialect(s): Typescript
• I don’t know.

Would you be willing to resolve this issue by submitting a Pull Request?

• Yes, I have the time and I know how to start.
• Yes, I have the time but I don’t know how to start, I would need guidance.
• No, I don’t have the time, although I believe I could do it if I had the time…
• No, I don’t have the time and I wouldn’t even know how to start.

[Reinoptland]

Hey @Crodaycat & others

I am also working on my first Sequelize / Typescript selfstudy project. I found this example to be pretty useful (though it is from 2 years ago)

https://github.com/ahmerb/typescript-sequelize-example

[papb]

I finally figured out how to make it work.

Nice!!

More examples would be good, however.

I agree 😬 Would you be willing to post how did you finally make it work?