\n\n\n[](https://dl.circleci.com/status-badge/redirect/gh/travelperk/fabricator/tree/master)\n\n## The Problem\n\nFabricator is based on the excellent\n[Fabrication](https://www.fabricationgem.org/). Its purpose is to easily\ngenerate objects in JavaScript. It is particularly useful for testing.\n\n## Installation\n\n`npm install --dev @travelperksl/fabricator`\n\n## Defining Models\n\nModels are defined with `Fabricator()` in this way:\n\n```js\nimport { Fabricator, sequence } from '@travelperksl/fabricator'\nimport faker from 'faker'\n\nconst userFabricator = Fabricator({\n id: () => sequence('userId'),\n name: () => faker.name.firstName() + faker.name.lastName(),\n admin: false,\n})\n```\n\nYou simply pass a model definition. The definition is an object where each key\nis a function or a static value. If you need dynamic data you can use\n`sequence()` or use a library like [faker](https://www.npmjs.com/package/faker).\n\nYou can also extend existing models. For example:\n\n```js\nconst adminFabricator = userFabricator.extend({ admin: true })\n```\n\nIn this case, `adminFabricator` will inherit all the properties from\n`userFabricator` but will overwrite the value for the `admin` property.\n\n## Fabricating Objects\n\nOnce your model is defined you can create it by calling the returned function:\n\n```js\nconst user = userFabricator()\n// => { id: 1, name: 'John Doe', admin: false }\nconst admin = adminFabricator()\n// => { id: 2, name: 'Susan Smith', admin: true }\n```\n\nYou can overwrite some values by passing a model definition as parameter:\n\n```js\nconst blockedUser = userFabricator({ isBlocked: true })\n// => { id: 3, name: 'Donald Brown', admin: false, isBlocked: true }\n```\n\nNote that there's a difference between passing a function and a static value in\na fabricator definition. A function gets executed every time you create a new\nobject, a constant value is cached. Consider the following example:\n\n```js\nconst withConstant = Fabricator({ foo: Math.random() })\nwithConstant() // => { foo: 0.11134742452557367 }\nwithConstant() // => { foo: 0.11134742452557367 }\nwithConstant() // => { foo: 0.11134742452557367 }\n\nconst withMethod = Fabricator({ foo: () => Math.random() })\nwithMethod('withMethod') // => { foo: 0.4426388385403983 }\nwithMethod('withMethod') // => { foo: 0.572825488636862 }\nwithMethod('withMethod') // => { foo: 0.4322506522885017 }\n```\n\n### Fabricator.times()\n\nIf you need to quickly generate more than one object you can use\n`Fabricator.times()`:\n\n```js\nconst people = userFabricator.times(2)\n// => [{ id: 3, ... }, { id: 4, ... }]\n\nconst colleagues = userFabricator.times(2, { companyId: 5 })\n// => [{ id: 5, companyId: 5 }, { id: 6, companyId: 6 }]\n```\n\nIf you need a random number of items you can pass an object with the properties\n`min` and `max`:\n\n```js\nuserFabricator.times({ max: 5 }) // => a random length from 1 to 5\nuserFabricator.times({ min: 0, max: 5 }) // => a random length from 0 to 5\nuserFabricator.times({ min: 0 }) // => a random length from 0 to 10\n```\n\n### sequence()\n\nSometimes it can be useful to have an increasing value for a field, for example\n`id`. You can do this with `sequence()`\n\n```js\nsequence() // => 1\nsequence() // => 2\nsequence() // => 3\n```\n\nIn some cases you might want to have different sequences, you can simply pass a\nsequence name:\n\n```js\nsequence('user') // => 1\nsequence('company') // => 1\nsequence('user') // => 2\nsequence('user') // => 3\nsequence('company') // => 2\n```\n\n### sequence.reset()\n\nIf you are checking the sequence id, for example if you do\n[snapshot testing](https://facebook.github.io/jest/docs/en/snapshot-testing.html)\nyou want your sequence numbers to be the same every time you execute your test.\nIn this case you can simply reset the sequence before running the test:\n\n```js\nsequence('user') // => 1\nsequence('company') // => 1\nsequence('user') // => 2\nsequence('company') // => 2\n\nsequence.reset()\n\nsequence('user') // => 1\nsequence('company') // => 1\nsequence('user') // => 2\nsequence('company') // => 2\n\nsequence.reset('company')\n\nsequence('user') // => 3\nsequence('company') // => 1\nsequence('user') // => 4\nsequence('company') // => 2\n```\n","readmeFilename":"README.md","keywords":["fabricator","fabrication","fabricate","testing"]}
![\"wrench\"](\"https://raw.githubusercontent.com/travelperk/fabricator/master/images/wrench.png\")
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