TypeScript from JSON Schema

This is a TypeScript definitions that can automatically generate TypeScript types given JSON Schema definitions without the need of any code generator.

The caveat is that the JSON Schema must be declared using string literals instead of generic strings, this is achieved by declaring the objects as const.

The associated helper files will aid that task with some constants and functions that returns properly typed constructions.

Install

yarn add @profusion/json-schema-to-typescript-definitions

If you don't use our commonSchemas or schemaHelpers, you can use it as a --dev dependency since the TypeScript checks are done only in compile time.

Usage

import type { TypeFromJSONSchema } from '@profusion/json-schema-to-typescript-definitions';

type MyObject = TypeFromJSONSchema<{
  type: 'object';
  properties: {
    a: { type: 'boolean' };
  };
  additionalProperties: false;
}>;
const o: MyObject = { a: true };

One can also use the function helpers to get properly typed objects:

import { commonSchemas, schemaHelpers } from '@profusion/json-schema-to-typescript-definitions';

// declares an actual schema object, you can use with Ajv and others
const schema = schemaHelpers.object({
  properties: {
    a: commonSchemas.boolean,
  },
});
const o: TypeFromJSONSchema<typeof schema> = { a: true };

Similar Packages

This package is similar to json-schema-to-typescript, however that one uses a code-generator that can work out JSON files.

This package requires as const so strings are kept as literals, but requires no code generation. If you define your JSON schemas using TypeScript, then you can avoid that code generation burden.

License

Open source - MIT.