feat(objection): add model relationship decorators

[rossyman]

Information

Type	Breaking change
Feature	No

First time contributor here 😄 If there are any striking concerns about this PR then please let me know, as I'm happy to work on it. I thought that it'd be useful for developers to use decorators to describe relationships via Objection.

This PR hopefully honours the way that Objection's Graph and Relationship Querying APIs work -- whilst also ensuring the consumer's domain model is a bit more strict, by actually defining related properties on an entity as optional, instead of only loosely defining them via relationMappings.

The sensible defaults these decorators provide for joining keys are based on the use of @IdColumn and @Entity. The defaults supplied are based on the Objection relationship documentation and follow the same nomenclature with the ability for a user to override the keys / table path in the decorator factory params.

---

Usage example

/**
 * All work in a similar manner:
 * - @HasMany, @HasOne, @HasOneThroughRelation, @ManyToMany, @RelatesTo
 */
import { Entity, IdColumn, BelongsToOne } from '@tsed/objection';

@Entity("user")
class User extends Model {
  @IdColumn()
  id!: string;
}

@Entity("movie")
class Movie extends Model {

  @IdColumn()
  id!: string;

  ownerId!: string;

  @BelongsToOne()
  owner?: User;
}

// Retrieve the related user
const owner = await Movie.relatedQuery('owner').for(1);

// Retrieve the movie with their owner
const movie = await Movie.query().withGraphFetched('owner');

Todos

• Tests
• Coverage
• Example
• Documentation

[rossyman]

Some extra thought I had on this PR:

• It would be nice if we could infer the modelClass from the type defined on the property (Not even sure if this is possible)
• It would be nice if we could make the join options supplied to this decorator less nested

[rossyman]

Last thought I had on this, was that:

• It would be nice if we could set a sensible default for relationship joins

[Romakita]

Hello @rossyman,

It seems to be ok for me :) Good PR.

The documentation over the new decorators is missing. Don't forget to add it in /docs/tutorials/objection.md ;)

See you
Romain

[rossyman]

Updated the documentation and fixed the build/test phase -- One point, is that I'm not sure what I need to do for viewpress to find these new decorators, as at the moment, they're not showing up in the <ApiList> component in the markdown.

[Romakita]

@rossyman you can take as example the mongoose.md where the ApiList is used to display mongoose decorators ;)

[rossyman]

Ah okay so it seems the API is queried from tsed.io -- So makes sense these don't show up yet as they're not released.

[Romakita]

Ah okay so it seems the API is queried from tsed.io -- So makes sense these don't show up yet as they're not released.

It's possible to regenerate locally the api.json file by running the command: yarn docs:serve. But this command, works only on linux/mac Os.

I'll checkout your PR to verify if the ApiList is correctly configured for Objection page.

See you
Romain

[rossyman]

Tests are running into an issue with array types. Sadly this issue (microsoft/TypeScript#7169) has been open for 6 years now, so I'll add in some extra parameters to the configuration for relationships that are plural to expose this type.

[rossyman]

I can now confirm that the tests and docs are all building / passing correctly 😄

[Romakita]

@rossyman Great job ;)

Just small cosmetics changes !

See you
Romain

[rossyman]

Good to go! 🚀

[rossyman]

Just on a side note, Objection.js isn't listed under the Plugins sidebar section on the docs site. -- Added it in this PR as a separate commit.

[Romakita]

@rossyman Perfect PR ;)

Ready to merge for me!

[Romakita]

🎉 This PR is included in version 6.131.0 🎉

The release is available on:

• v6.131.0
• GitHub release

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[Romakita]

🎉 This PR is included in version 7.0.0-rc.6 🎉

The release is available on:

• v7.0.0-rc.6
• GitHub release

Your semantic-release bot 📦🚀