@type-map-for/avro

Generate Avro schemas from TypeScript interfaces at compile time with union types for optional fields.

Installation

npm install @type-map-for/avro

Usage

import type { AvroSchema } from '@type-map-for/avro';

interface User {
  id: string;
  name: string;
  email?: string;
  tags: string[];
  metadata?: { source: string };
}

type UserSchema = AvroSchema<User>;
// Result: {
//   type: 'record'
//   fields: Array<{
//     { name: 'id'; type: 'string' }
//     { name: 'name'; type: 'string' }
//     { name: 'email'; type: ['null', 'string'] }
//     { name: 'tags'; type: { type: 'array'; items: 'string' } }
//     { name: 'metadata'; type: ['null', 'bytes'] }
//   }>
// }

// Use with schema validation
const userSchema: UserSchema = {
  type: 'record',
  fields: [
    { name: 'id', type: 'string' },
    { name: 'name', type: 'string' },
    { name: 'email', type: ['null', 'string'] },
    { name: 'tags', type: { type: 'array', items: 'string' } },
    { name: 'metadata', type: ['null', 'bytes'] }
  ]
} as const satisfies UserSchema;

Type Mapping

| TypeScript | Avro | |------------|------| | string | 'string' | | number | 'int' | 'double' | | boolean | 'boolean' | | object | 'bytes' | | T[] | { type: 'array', items: T } | | T \| undefined | ['null', T] (union type) | | T[] \| undefined | ['null', { type: 'array', items: T }] |

Types

• AvroType<T> - Avro type definition for TypeScript type T
• AvroField<T, K> - Schema field for property K of type T
• AvroSchema<T> - Complete Avro record schema for interface T

Contributing

Issues and pull requests welcome at github.com/nathancanine/type-map-for.

License

MIT