@typedly/schema

A TypeScript type definitions package for schema modeling.

Features

• Type-level schema-to-TypeScript conversion (SchemaToType)
• Optional key support via ? marker (e.g. email?)
• Primitive schema mapping (string, number, boolean, date)
• Array schema support for primitives and nested object items
• Zero runtime cost (types only)

Table of contents

• Installation
• Api
  • Type
    • SchemaRecordToType
    • SchemaToType
    • SchemaTypeMap
    • SchemaValue
• Examples
• Contributing
• Support
• Code of Conduct
• Git
  • Commit
  • Versioning
• License
• Packages

Installation

npm install @typedly/schema --save-peer

Api

import {
  SchemaRecordToType,
  SchemaToType,
  SchemaTypeMap,
  SchemaValue,
} from '@typedly/schema';

Type

SchemaRecordToType

import { SchemaRecordToType } from '@typedly/schema';

type dbSchema = SchemaRecordToType<{
  person: { id: 'number', name: 'string' },
  cart: { id: 'number', items: { array: 'string' } },
}>;

// Result:
// type dbSchema = {
//   person: {
//     id: number;
//     name: string;
//   };
//   cart: {
//     id: number;
//     items: string[];
//   };
// }

SchemaToType

import type { SchemaToType } from '@typedly/schema';

// Oops, an end user writes this:
const OopsSchema = {
  tags: ["a", "b"] // native string[]! Not the schema style, but tolerated
}
type Result = SchemaToType<typeof OopsSchema>
// tags: string[]   (instead of never)

SchemaTypeMap

import { SchemaTypeMap } from '@typedly/schema';

SchemaValue

import { SchemaValue } from '@typedly/schema';

// 1a. Primitive array:
type Ex1 = SchemaValue<{ array: 'string' }>;
// => string[]

// 1b. Nested object array:
type Ex2 = SchemaValue<{ array: { id: 'number', name: 'string' } }>;
// => { id: number; name: string; }[]

// 1c. Deeply nested arrays:
type Ex3 = SchemaValue<{ array: { array: 'boolean' } }>;
// => boolean[][]

// 2. Primitive type:
type Ex4 = SchemaValue<'string'>; // string
// => string

type Ex5 = SchemaValue<'number'>; // number
// => number

type Ex6 = SchemaValue<'boolean'>; // boolean
// => boolean

type Ex7 = SchemaValue<'date'>;    // Date
// => Date

// 4. readonly any[] — Native TypeScript array (forgiveness fallback)
type Ex8 = SchemaValue<string[]>; // string[]

// 5. Record<string, any> — Nested object (schema for object)
type Ex9 = SchemaValue<{ id: 'number'; name: 'string' }>;
// => { id: number; name: string; }

// 6. Invalid types (not in SchemaTypeMap, not an array, not a nested object)
type Ex13 = SchemaValue<null>;      // never
type Ex14 = SchemaValue<undefined>; // never
type Ex15 = SchemaValue<()=>void>;  // never
type Ex16 = SchemaValue<42>;        // never

Examples

Providing

import type { SchemaToType } from '@typedly/schema';

function createSchema<const Schema extends Record<string, unknown>>(schema: Schema) {
  return (user: SchemaToType<Schema>) => user;
}

// 
const userSchema = createSchema({
  id: "number",
  name: "string",
  active: "boolean",
  createdAt: "date",
})({
  id: 1,
  name: "John",
  active: true,
  createdAt: new Date(),
});

1) Basic schema to type

import type { SchemaToType } from '@typedly/schema';

type UserSchema = {
  id: 'number';
  name: 'string';
  active: 'boolean';
  createdAt: 'date';
};

type User = SchemaToType<UserSchema>;
// {
//   id: number;
//   name: string;
//   active: boolean;
//   createdAt: Date;
// }

2) Optional keys with ?

import type { SchemaToType } from '@typedly/schema';

type UserSchema = {
  id: 'number';
  name: 'string';
  email?: 'string';
};

type User = SchemaToType<UserSchema>;
// {
//   id: number;
//   name: string;
//   email?: string;
// }

3) Arrays of primitives

import type { SchemaToType } from '@typedly/schema';

type PostSchema = {
  id: 'number';
  tags: { array: 'string' };
  ratings: { array: 'number' };
};

type Post = SchemaToType<PostSchema>;
// {
//   id: number;
//   tags: string[];
//   ratings: number[];
// }

4) Arrays of objects

import type { SchemaToType } from '@typedly/schema';

type UserSchema = {
  id: 'number';
  test: { array: { id: 'number'; label: 'string' } };
};

type User = SchemaToType<UserSchema>;
// {
//   id: number;
//   test: { id: number; label: string }[];
// }

5) Nested object schema

import type { SchemaToType } from '@typedly/schema';

type AccountSchema = {
  id: 'number';
  profile: {
    firstName: 'string';
    lastName: 'string';
    'phone?': 'string';
  };
};

type Account = SchemaToType<AccountSchema>;
// {
//   id: number;
//   profile: {
//     firstName: string;
//     lastName: string;
//     phone?: string;
//   };
// }

Contributing

Your contributions are valued! If you'd like to contribute, please feel free to submit a pull request. Help is always appreciated.

Support

If you find this package useful and would like to support its and general development, you can contribute through one of the following payment methods. Your support helps maintain the packages and continue adding new.

Support via:

• 4Fund
• DonorBox
• GitHub
• Ko-fi
• OpenCollective
• Patreon
• PayPal
• Stripe
• ~~Revolut~~

or via Trust Wallet

• BNB
• BTC
• ETH
• USDT (BEP20)
• XLM

Thanks for your support!

Code of Conduct

By participating in this project, you agree to follow Code of Conduct.

GIT

Commit

• AngularJS Git Commit Message Conventions
• Karma Git Commit Msg
• Conventional Commits

Versioning

Semantic Versioning 2.0.0

Given a version number MAJOR.MINOR.PATCH, increment the:

• MAJOR version when you make incompatible API changes,
• MINOR version when you add functionality in a backwards-compatible manner, and
• PATCH version when you make backwards-compatible bug fixes.

Additional labels for pre-release and build metadata are available as extensions to the MAJOR.MINOR.PATCH format.

FAQ How should I deal with revisions in the 0.y.z initial development phase?

The simplest thing to do is start your initial development release at 0.1.0 and then increment the minor version for each subsequent release.

How do I know when to release 1.0.0?

If your software is being used in production, it should probably already be 1.0.0. If you have a stable API on which users have come to depend, you should be 1.0.0. If you’re worrying a lot about backwards compatibility, you should probably already be 1.0.0.

License

MIT © typedly (license)

Packages

• @typedly/array: A TypeScript type definitions package to handle array-related operations.
• @typedly/callback: A TypeScript type definitions package for asynchronous and synchronous callback functions of various types.
• @typedly/character: A TypeScript type definitions package for various character types.
• @typedly/context: A TypeScript type definitions package for context data structures.
• @typedly/descriptor: A TypeScript type definitions package for property descriptor.
• @typedly/digit: A TypeScript type definitions package for digit types.
• @typedly/letter: A TypeScript type definitions package for handling letter types.
• @typedly/object: A TypeScript type definitions package to handle object-related operations.
• @typedly/payload: A TypeScript type definitions package for payload data structures.
• @typedly/property: A TypeScript type definitions package to handle object property-related operations.
• @typedly/regexp: A TypeScript type definitions package for RegExp.
• @typedly/symbol: A TypeScript type definitions package for various symbols.