@hermiforge-decorix/json-schema

JSON Schema adapter for Decorix metadata. It emits JSON Schema draft 2020-12 objects from decorated classes or builder metadata.

Full usage guide: docs/ (narrative walkthrough beyond this package's API reference).

Install

pnpm add @hermiforge-decorix/core @hermiforge-decorix/json-schema

Peer dependencies: none.

Decorated Class

import {Email, Label, MinLength, Model, Required} from '@hermiforge-decorix/core';
import {toJsonSchema} from '@hermiforge-decorix/json-schema';

@Model('SignupDto')
class SignupDto {
  @Required('Name is required')
  @MinLength(2, 'Name is too short')
  @Label('Name')
  name!: string;

  @Required('Email is required')
  @Email('Invalid email')
  email!: string;
}

const schema = toJsonSchema(SignupDto);

Builder Model

import {model, stringField} from '@hermiforge-decorix/core';
import {toJsonSchema} from '@hermiforge-decorix/json-schema';

const SignupDto = model('SignupDto', {
  name: stringField().required('Name is required').minLength(2, 'Name is too short').label('Name'),
  email: stringField().required('Email is required').email('Invalid email')
});

const schema = toJsonSchema(SignupDto);

Import (JSON Schema → metadata)

fromJsonSchema performs the best-effort inverse of toJsonSchema: standard keywords map back to native constraints, and Decorix-specific x-decorix-constraints entries are restored verbatim, so toJsonSchema(fromJsonSchema(schema)) is stable for Decorix-produced schemas. Arbitrary custom validator/predicate functions cannot be reconstructed and are preserved as the '[function]' sentinel.

import {validate} from '@hermiforge-decorix/core';
import {fromJsonSchema} from '@hermiforge-decorix/json-schema';

const metadata = fromJsonSchema({
  title: 'SignupDto',
  type: 'object',
  properties: {
    name: {type: 'string', minLength: 2},
    email: {type: 'string', format: 'email'}
  },
  required: ['name', 'email']
});

validate({name: 'Al', email: '[email protected]'}, metadata); // { success: true, ... }

Validator Notes

@hermiforge-decorix/json-schema emits schema data only and does not need a ValidatorAdapter.

Security Note

Only call fromJsonSchema on schemas you trust — generated by toJsonSchema, or otherwise audited. A pattern keyword (or a RegExp restored from x-decorix-constraints) becomes a live RegExp that Decorix re-runs on every validation; a schema from an untrusted source (a third-party upload, an unreviewed import) could carry a catastrophically backtracking pattern (ReDoS). fromJsonSchema performs no complexity/length limiting on imported patterns.

License

LGPL-3.0-or-later — see the repository LICENSE.