@axonsdev/hateoas-nestjs-typeorm

Assisted TypeORM integration for @axonsdev/hateoas-nestjs.

This package helps build Siren resource definitions from TypeORM entities while keeping explicit control over exposed fields.

Responsibilities

• Build a HypermediaResourceDefinition for a TypeORM entity.
• Generate property mappings from an explicit expose list.
• Optionally validate exposed columns against TypeORM metadata.
• Preserve the same links, actions, profiles, and context model as @axonsdev/hateoas-nestjs.

Main Exports

defineTypeOrmSirenResource(entity, options)
TypeOrmSirenResourceOptions

Basic Usage

export const articleResource = defineTypeOrmSirenResource<Article, { user: User }>(Article, {
  dataSource,
  name: 'article',
  classes: ['article'],
  id: (entity) => entity.id,
  expose: ['id', 'title', 'status'],
  profiles: {
    list: {
      expose: ['id', 'title', 'status'],
      links: ['self'],
      actions: [],
    },
  },
  links: {
    self: ({ entity, url }) => sirenLink('self', url.route('articles.findOne', { id: entity.id })),
  },
});

expose Is Mandatory

The package intentionally does not expose every TypeORM column automatically.

expose: ['id', 'title', 'status']

This prevents accidental leaks of sensitive fields such as passwords, tokens, internal flags, or audit data.

Custom Properties

You can add computed properties or override generated mappings:

defineTypeOrmSirenResource(UserEntity, {
  expose: ['id', 'email'],
  properties: {
    displayName: ({ entity }) => `${entity.firstName} ${entity.lastName}`,
  },
  // links, actions, profiles...
});

Generated mappings from expose are merged first. properties are merged afterward.

Metadata Validation

When dataSource is provided, every exposed field is checked against TypeORM column metadata.

defineTypeOrmSirenResource(UserEntity, {
  dataSource,
  expose: ['id', 'email'],
  // ...
});

If an exposed field is not a known column, the function throws an error.

This is a guard against typos and stale resource definitions.

Relationship To @axonsdev/hateoas-nestjs

The result is a normal HypermediaResourceDefinition, so it can be registered in HateoasModule.forRoot(...):

HateoasModule.forRoot({
  resources: [articleResource],
  routes,
});

Current Limitations

• It does not automatically expose relations.
• It does not automatically generate links from TypeORM relations.
• It does not infer profiles.
• It does not infer actions.
• It validates columns only when a DataSource is supplied.

These constraints are intentional for the first version: representation exposure should stay explicit.