Auto-typegen NPM

auto-typegen 🚀

Automatically generate TypeScript interfaces from JSON data, API responses, or database schemas. Perfect for Mongoose, Sequelize, and raw data. Simplify your workflow and ensure type safety with just one function call!

Features ✨

Instant Type Generation: Convert JSON/API responses to TypeScript interfaces in one call.
ORM Support: Works seamlessly with Mongoose and Sequelize.
Universal: Runs in Node.js (writes files) and browsers (triggers downloads).
Zero Config: Simple API with smart defaults.
Nested Objects: Handles complex data structures effortlessly.

Installation 💻

npm install auto-typegen
# or
yarn add auto-typegen

Usage 🚀

1. In React ⚛️

import { createTypedFetch } from 'auto-typegen';

const fetchTodo = async () => {
  const res = await fetch('https://api.example.com/todos/1');
  const todo = await res.json();

  await createTypedFetch({
    interfaceName: 'Todo',
    data: todo,
    outputPath: 'TodoType.ts',
  });
};

Browser Behavior: Triggers a download of `TodoType.ts` with:

interface Todo {
  userId: number;
  id: number;
  title: string;
  completed: boolean;
}

export { Todo };

2. Basic Example (Node.js)

import { createTypedFetch } from 'auto-typegen';

const user = {
  id: 1,
  name: 'Alice',
  email: 'alice@example.com',
  roles: ['admin', 'user'],
};

createTypedFetch({
  interfaceName: 'User',
  data: user,
  outputPath: './types/user-types.ts',
});

Generated File (user-types.ts):

interface User {
  id: number;
  name: string;
  email: string;
  roles: string[];
}

export { User };

3. With Mongoose 🍃

import { createTypedFetch } from 'auto-typegen';
import UserModel from './models/User';

const user = await UserModel.findOne({ email: 'test@example.com' });

createTypedFetch({
  interfaceName: 'User',
  data: user,
  outputPath: './types/mongoose-user.ts',
});

Output:

interface User {
  _id: string;
  email: string;
  createdAt: Date;
  updatedAt: Date;
  __v: number;
}

export { User };

4. With Sequelize 🗄️

import { createTypedFetch } from 'auto-typegen';
import Product from './models/Product';

const product = await Product.findByPk(123);

createTypedFetch({
  interfaceName: 'Product',
  data: product,
  outputPath: './types/sequelize-product.ts',
});

Output:

interface Product {
  id: number;
  name: string;
  price: number;
  createdAt: Date;
  updatedAt: Date;
}

export { Product };

5. With Raw SQL Data 🐬

import { createTypedFetch } from 'auto-typegen';
import { executeQuery } from './database';

const results = await executeQuery('SELECT * FROM orders WHERE user_id = 456');

createTypedFetch({
  interfaceName: 'Order',
  data: results[0],
  outputPath: './types/sql-order.ts',
});

Output:

interface Order {
  id: number;
  user_id: number;
  total: number;
  created_at: Date;
}

export { Order };

API 📚

`createTypedFetch(options)`

Generates and saves TypeScript interfaces.

Options

Parameter	Type	Required	Description
`interfaceName`	`string`	Yes	Name for the root interface (e.g., "User")
`data`	`any`	Yes	Data object to analyze
`outputPath`	`string`	Yes	File path to save interfaces (e.g., "./types/user.ts")

FAQ ❓

Q: How do I handle circular references? A: The library automatically detects and handles circular references by using any for the offending fields.

Q: Can I customize date handling? A: Dates are always typed as Date. For custom formatting, transform your data first.

Q: Does it work with Next.js/Nuxt.js? A: Yes! Works in any Node.js or browser environment.