Monke mock

A fast mock data generator with a great typescript support and no 3rd party dependencies.

Introduction

I could not find any cool package for quickly creating a mock schema of objects and arrays for my unit tests or just to populate site with random data. That is why I decided to create my own version of it.

Benefits of using monke-mock

While faker.js provides an excellent generator for data like emails, names, etc. it is not suitable for generating developer-defined shapes of data. Let's say that you want to have an array of objects for testing purposes. While it is possible, but not straightforward to accomplish using the faker.js, it is extremely easy with monke-mock.

Faker way:

const arr = [];
for(let i = 0; i < 100; i++){
    arr.push({
        x: faker.datatype.number()
    });
}

Monke-mock way:

const data = Marray(MObject({x: Mnum()})).Length(100).generate();

Getting started

Install with:

npm install monke-mock

yarn add monke-mock

Currently monke-mock supports following data types:

• number - Mnum
• string - Mstring
• object - Mobject
• array - Marray
• Date - Mdate

Data type	Function	Available modifiers
number	Mnum	Max(), Min(), IsInt()
string	Mstring	Length(), UseNumbers()
date	Mdate	Max(), Min()
object	Mobject
array	Marray	Length()

Examples

Generating a number

import { Mnum } from 'monke-mock';

const x = Mnum().generate();

You can also specify Min and Max values:

import { Mnum } from 'monke-mock';

const x = Mnum().Min(21).Max(37).generate();

Generating a negative number

import { Mnum } from 'monke-mock';

const x = Mnum().Min(-100).Max(0).generate();

Generating an array of strings

import { Marray, Mstring } from 'monke-mock';

const x = Marray(Mstring()).generate();

Generating an object with one key always equal to 1

import { Mobject, Mstring } from 'monke-mock';

const x = Mobject({fixedKey: 1, someRandomString: Mstring()}).generate();

Creating a custom generator

import { Mcustom, Marray, IMockGenerator } from 'monke-mock';


// First define a class that implements the IMockGenerator
class ACustomGenerator implements IMockGenerator<number> {
    
    // the generate() function should implement the algorithm that returns the random data 
    generate(): number {
        return Date.now() % 2 ? 1 : -1;
    }
}

// Then use the `Mcustom` function to wrap the class
const x = Marray(Mcustom(ACustomGenerator));