ts-mimic v0.0.2

TypeScript Data Generator

What

Use TypeScript to generate endless mock data.

Why

TypeScript's type system is very expressive and easy to use, making it perfect to define the shape of mock data.

ts-mimic was built to easily define mock data sent to EventHub: https://eventhub.chriscaruso.dev

How

ts-mimic provides a set of types that map to specific types of mock data. It can even guess the kind of mock data just from property names!

Installation

Install this package through npm

npm i ts-mimic typescript@~4.1.5

Examples

Try it out: https://mimic.chriscaruso.dev

Simple example

import { mimic } from 'ts-mimic';

const ts = `
interface Person {
    firstName: asFirstName; // Use built in mock data generators. See below for a complete list.
    lastName: asLastName;
    age: asNumberRange<20, 30>; // Some mock data generators can take parameters to customize them.
    address; // Auto detect mock data from the property name.
    secondaryAddress?: asSecondaryAddress; // Properties can be optional. These have a 50% chance of being undefined.
    state?;
    city: asCity;
    image: Sometimes<.75, asImagePeople>; // Sometimes is a special type that lets you specify the chance a value will be defined
}`;

const { map: { Person } } = mimic(ts);
const mockPerson = Person();

console.log(mockPerson);

Possible output

{
    firstName: "Zion",
    lastName: "Block",
    age: 23,
    address: "25612 Rath Avenue",
    secondaryAddress: undefined,
    state: "Utah",
    city: "Alvinaview",
    image: "http://placeimg.com/640/480/people",
}

Full example

Play with this example live at https://mimic.chriscaruso.dev

import { mimic } from 'ts-mimic';

const ts = `
interface Name {
    firstName: asFirstName; // Use built in mock data generators. See below for a complete list.
    lastName: asLastName;
}

interface Address {
    address; // Auto detect mock data
    secondaryAddress?: asSecondaryAddress; // Properties can be optional. These have a 50% chance of being undefined
    state?;
    city: \`City: \${asCity}\`; // Use template literals to define compound strings
}

interface BitcoinWallet {
    type: 'bitcoin'; // Use type literals for static data
    bitcoinAddress;
}

interface EtheriumWallet {
    type: 'etherium';
    etheriumAddress;
}

// Use type aliases to create convenient types (ex. union, array, literal types)
type DigitalWallet = BitcoinWallet | EtheriumWallet; // Union types for an equal chance at any of them

interface Person {
    name: Name; // Reference other defined types
    address: Address;
    digitalWallet?: DigitalWallet;
    age: asNumberRange<20, 30>; // Some mock data generators can take parameters to customize them.
    image?: Sometimes<.75, asImagePeople>; // Sometimes is a special type that lets you specify the chance a value will be defined
}

// Use type aliases to represent type literals
type Team = {
    members: BoundArray<Person, 6, 2>; // BoundArray is a special type that lets you specify the range of an array
};

// Use type aliases to represent top level array types
type People = Person[]; // Arrays have a random range of 0 to 10 elements

// Use tuples to represent more precise arrays
type Couple = [Person, Person];`;

const { definitions } = mimic(ts);

// Print out each generator's possible output
for (const { name, generator } of definitions) {
    console.log(
        name, 
        generator(),
    );
}

Provided types

Special types

Generator types