Interface Faker

Generate realistic mock data for TypeScript interfaces using faker.js and ts-morph.

Installation

npm install interface-faker
# or
pnpm add interface-faker
# or
yarn add interface-faker

Usage

import { createFakeGenerator } from 'interface-faker';

// Define your interface
interface User {
  id: string;
  name: string;
  email: string;
  age: number;
  isActive: boolean;
  createdAt: Date;
  profile?: {
    bio: string;
    avatar: string;
  };
}

// Generate mock data
const generateUsers = createFakeGenerator<User>("User", __filename);

// Generate a single user (returns array with 1 item)
const singleUser = generateUsers(1)[0];

// Generate multiple users
const users = generateUsers(10);

console.log(users);

Advanced Usage

Smart Property Detection

Interface Faker automatically detects common property patterns and generates appropriate fake data:

• Email: Properties containing "email" → faker.internet.email()
• Name: Properties containing "name" → faker.person.fullName()
• Phone: Properties containing "phone" → faker.phone.number()
• Currency: Properties containing "currency" → faker.finance.currencyCode()
• ID: Properties containing "id" → faker.string.uuid()
• Address: Properties containing "address" → faker.location.streetAddress()
• URL: Properties containing "url" or "link" → faker.internet.url()

API Reference

mockInterface<T>(interfaceName, filePath, options?)

Generates a mock function for a TypeScript interface.

Parameters

• interfaceName (string): Name of the interface to mock
• filePath (string): Path to the file containing the interface (use __filename)

Returns

Function that generates mock data: (count?: number) => T[]

Supported Types

• ✅ Primitive types (string, number, boolean, Date)
• ✅ Arrays
• ✅ Optional properties
• ✅ Union types
• ✅ Literal types
• ✅ Enum types
• ✅ Nested objects
• ✅ Record types
• ✅ Interface references

Requirements

• TypeScript >= 4.0.0
• Node.js >= 18.0.0

License

MIT