https://github.com/skovy/cooky-cutter

🍪 Object factories for testing in TypeScript
https://github.com/skovy/cooky-cutter

factory javascript jest mocha testing typescript

Last synced: 28 days ago
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🍪 Object factories for testing in TypeScript

• Host: GitHub
• URL: https://github.com/skovy/cooky-cutter
• Owner: skovy
• License: mit
• Created: 2018-06-24T17:09:16.000Z (over 6 years ago)
• Default Branch: master
• Last Pushed: 2022-06-03T02:04:56.000Z (over 2 years ago)
• Last Synced: 2024-10-01T05:53:05.800Z (about 1 month ago)
• Topics: factory, javascript, jest, mocha, testing, typescript
• Language: TypeScript
• Homepage: https://skovy.github.io/cooky-cutter/
• Size: 591 KB
• Stars: 133
• Watchers: 2
• Forks: 4
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE

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README

        
# 🍪 cooky-cutter

**Simple, type safe\* object factories for JavaScript tests.** (_\*with TypeScript_)

[![Travis branch](https://img.shields.io/travis/skovy/cooky-cutter/master.svg)](https://travis-ci.org/skovy/cooky-cutter)

[![Coverage Status](https://coveralls.io/repos/github/skovy/cooky-cutter/badge.svg?branch=master)](https://coveralls.io/github/skovy/cooky-cutter?branch=master)

[![npm](https://img.shields.io/npm/v/cooky-cutter.svg)](https://www.npmjs.com/package/cooky-cutter)

[![npm type definitions](https://img.shields.io/npm/types/cooky-cutter.svg)](https://www.npmjs.com/package/cooky-cutter)

**[Read the Release Annoucement](https://skovy.dev/object-factories-for-testing-in-typescript/)**.

## The problem

You need to write maintainable tests for JavaScript. The code depends on

specific entity types defined in the data model. These entities might initially

get stubbed out in tests (Mocha, Jest, etc) as plain objects. As complexity

grows, you move to factory functions (or another package that does this) to

avoid the duplication. A new column gets added, an old one gets removed or maybe

an entirely new entity is added. The breaking change isn't noticed until the

entire test suite runs (or maybe never).

## The solution

[`cooky-cutter`](https://www.npmjs.com/package/cooky-cutter) is a light package

that leverages TypeScript to define and create factories. Simply pass the type

as a generic (assuming you already have a type or interface defined for each

entity type). Whenever the entity type changes, the factories become invalid!

## Installation

```bash

npm install --save-dev cooky-cutter

# or

yarn add --dev cooky-cutter

```

## Basic Usage

For more documentation and examples, read the [full documentation](https://skovy.github.io/cooky-cutter/).

```typescript

import { define, random, sequence } from "cooky-cutter";

// Define an interface (or type) for the entity

interface User {

  id: number;

  firstName: string;

  lastName: string;

  age: number;

}

// Define a factory that represents the defined interface

const user = define({

  id: random,

  firstName: i => `Bob #${i}`,

  lastName: "Smith",

  age: sequence

});

// Invoke the factory a few times

console.log(user());

// => { id: 980711200, firstName: 'Bob #1', lastName: 'Smith', age: 1 }

console.log(user());

// => { id: 1345667839, firstName: 'Bob #2', lastName: 'Smith', age: 2 }

console.log(user());

// => { id: 796816401, firstName: 'Bob #3', lastName: 'Smith', age: 3 }

```