mockmate

Mockmate is a lightweight mock data generator for JavaScript and TypeScript. It helps frontend and full-stack developers generate, filter, and extend JSON data from public APIs with a clean and declarative API.

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Features

• Works with JavaScript and TypeScript
• Zero configuration
• Uses real public APIs
• Fully typed API
• Extend and customize data
• Node.js and browser compatible

---

Installation

yarn add mockmate
npm install mockmate
pnpm add mockmate

Basic Usage

import { mockmate } from "mockmate";

const users = await mockmate({
  category: "users",
  quantity: 5,
});

Pick Fields

const users = await mockmate({
  category: "users",
  pick: ["name", "email"],
});

Extend Data

const users = await mockmate({
  category: "users",
  extend: {
    isActive: () => true,
    score: () => Math.floor(Math.random() * 100),
  },
});

Generate Schema

const users = await generate({
  quantity: 3,
  schema: {
    id: () => crypto.randomUUID(),
    username: () => `user_${Math.random().toString(36).slice(2)}`,
    age: () => Math.floor(Math.random() * 50) + 18,
    email: () => "[email protected]",
  },
});

Error Handling

try {
  await mockmate({ category: "users" });
} catch (error) {
  if (error instanceof Error) {
    console.error(error.message);
  }
}

Supported Categories

users
posts
comments
todos

Running Tests

Mockmate uses Jest for testing. You can run tests locally with:

pnpm add -D jest ts-jest @types/jest
pnpm jest

Or using npm/yarn:

npm install --save-dev jest ts-jest @types/jest
npm test

Example test structure:

// tests/mockmate.test.ts
import { mockmate } from "../src";

describe("mockmate", () => {
  it("should generate an array of users", async () => {
    const users = await mockmate({ category: "users", quantity: 3 });
    expect(users).toHaveLength(3);
    expect(users[0]).toHaveProperty("name");
  });

  it("should pick only selected fields", async () => {
    const users = await mockmate({
      category: "users",
      quantity: 1,
      pick: ["email"],
    });
    expect(users[0]).toHaveProperty("email");
    expect(users[0]).not.toHaveProperty("name");
  });
});

License

MIT