schema-faker

schema-faker generates massive amount of json fake data with zero coding, based on data type and json schema. It is also built with a simple faker server to serve mockup REST API. schema-faker uses faker.js to generate fake data.

const faker = new SchemaFaker(); // The default locale is en, data length is 10
faker.fake("integer"); // return a number
faker.fake("html"); // return html paragraphs
faker.fakeSchema({
  id: "integer",
  username: "username(6,20)",
  email: "email",
  profile: {
    first_name: "name.firstName",
    last_name: "name.lastName",
    about: "Hello! I'm living in {{address.cityName}} with 2 kids and 1 {{animal.dog}}.",
  },
}); // return fake object with the defined schema

$ yarn fake-server -b /api/v1 schema.json
The simple faker server is running at http://localhost:3000/api/v1

To create a custom mockup API server

const path = require("path");
const express = require("express");
const { SchemaFaker, fakeRouter } = require("schema-faker");
const mockup = fakeRouter(path.resolve(__dirname, "schema.json"), {
  locale: "de",
});

const server = express();
server.use("/mockup/api", mockup); // simply use schema-faker's mockup router
server.get("/:locale/other-fake-api", (req, res) => {
  const len = req.query.length || 10;
  const faker = new SchemaFaker(req.params.locale, len);
  const data = faker.fakeApi({ prop: otherSchema });
  res.json(data.prop);
});
// ...

Getting started

Install schema-faker

# Using yarn
yarn add --dev schema-faker
# Using npm
npm install --save-dev schema-faker

Typescript usage

import { SchemaFaker } from "schema-faker";

Javacript usage

const { SchemaFaker } = require("schema-faker");

const faker = new SchemaFaker(); // The default locale is en, data length is 10
// const faker = new SchemaFaker("ja", 20);
faker.fake("integer"); // return a number
faker.fake("integer(10,99)"); // return 2 digits number
faker.fake("html"); // return html paragraphs
faker.fake("html(3,6"); // return html with paragraphs number is from 3 to 6

const userSchema = {
  id: "integer",
  username: "username(6,20)",
  email: "email",
  first_name: "name.firstName",
  last_name: "name.lastName",
  password: "password",
  last_login: "datetime",
  gender: "gender",
  profile: {
    first_name: "name.firstName",
    last_name: "name.lastName",
    about: "Hello! I'm living in {{address.cityName}} with 2 kids and 1 {{animal.dog}}.",
    bio: "html(2,5)",
  },
};
faker.fakeSchema(userSchema); // return fake object with the defined schema

faker.fakeApi({
  Users: userSchema,
  Posts: {
    id: "integer(100000,999999)",
    author: "username(5,30)",
    content: "html(4,7)",
    summary: "lorem.paragraphs(2,3)",
    created_at: "datetime",
    published: "boolean",
    tags: ["words(1,2)", "animal.type"],
  },
});
/**
 * return json-server compatible mockup json
 * Data length of each data set is defined when initialized with new SchemaFaker(locale, dataLength)
 * {
 *   "Users": [
 *     {
 *       "id": ...
 *       "username": ...
 *       ...
 *     },
 *     {
 *       "id": ...
 *       "username": ...
 *       ...
 *     }
 *   ],
 *   "Posts": [
 *     {
 *       "id": ...
 *       "author": ...
 *       ...
 *     },
 *     {
 *       "id": ...
 *       "author": ...
 *       ...
 *     }
 *   ],
 * ]

CLI fake-server usage

With the cli fake-server, you can simply create a mock REST API with zero coding. Firstly, create a schema.json file with content is as same as the schema passed to faker.fakeApi(schema). Please refer to the sample schema: schema.json.

# fake-server requires express
yarn add --dev express

# using npm
# npx fake-server --help
yarn fake-server --help
fake-server [options] <schema json file>

Options:
      --help     Show help                                             [boolean]
      --version  Show version number                                   [boolean]
  -n, --length   The length of each generated data set             [default: 10]
  -l, --locale   The locale (eg. "ja", "de")                     [default: "en"]
  -p, --port     Set port                                        [default: 3000]
  -h, --host     Set host                                 [default: "localhost"]
  -b, --base     Set base url (e.g. /v2 or /api)                   [default: ""]

yarn fake-server -b /api/v1 schema.json
// The simple faker server is running at http://localhost:3000/api/v1

Now if you go to http://localhost:3000/api/v1/users or http://localhost:3000/api/v1/users/10346, you'll get your fake users.

CLI fake-data usage

If you just want to generate fake data to use it by your own way, please use the cli fake-data. For example, you can use json-server to serve your fake data.

yarn fake-data --help
fake-data [options] <schema json file>

Options:
      --help     Show help                                             [boolean]
      --version  Show version number                                   [boolean]
  -n, --length   The length of each generated data set             [default: 10]
  -l, --locale   The locale (eg. "ja", "de")                     [default: "en"]
  -o, --output   Write faked data to file                          [default: ""]

yarn fake-data -o mockupdb.json schema.json
# for example, use json-server to serve mockupdb.json
yarn add --dev json-server
json-server mockupdb.json

Data Types

Basic Types

const faker = new SchemaFaker("en", 10); // The default locale is en, data length is 10
// const faker = new SchemaFaker();
// const faker = new SchemaFaker("ja", 20);
faker.setLocale("de"); // change locale after initialized
faker.setLength(15);  // change data length after initialized

const min = 10;
const max = 99;
faker.fakeInteger(min, max); // return 2 digits number
faker.fake("integer(10,99)"); // same as above
faker.fakeString(min, max); // return a string whose length between min and max.
faker.fake("string(10,99)"); // same as above

faker.fake("float(10,99)"); // same as faker.fakeFloat(10,99)
faker.fake("boolean"); // same as faker.fakeBoolean()
faker.fake("date"); // format yyyy-mm-dd
faker.fake("time"); // format h:i:s
faker.fake("datetime"); // format yyyy-mm-dd h:i:s
faker.fake("image"); // return a fake image url
faker.fake("name"); // return a fake full name
faker.fake("username(6,20)"); // return a fake alphanumeric string whose length is from 6 to 20 
faker.fake("html(2,4)"); // return a fake html paragraphs with number of paragraphs is between 2 to 4

faker.js Types

schema-faker supports all types from faker.js

Usage: faker.fake(${type}) or faker.fake(${group}.${type}). With some specific types which have one numeric argument, such as words, paragraphs, you can use the following api:

faker.fake(`typename(${min},${max})`)
faker.fake(`group.typename(${min},${max})`)

Basically, schema-faker will try to find all grand-children properties of faker.js, it will call faker.js if there is any grand-child properties found. schema-faker also supports faker.js' mustache format.

faker.fake("address.city"); // same as faker.js's faker.address.city()
// schema-faker is smart to find city is property of address
faker.fake("city"); // same as faker.js's faker.address.city()

faker.fake("lorem.words(2,5)"); // same as faker.js's faker.lorem.words(n) with 2 <= n <= 5
// schema-faker is smart to find words is property of lorem
faker.fake("words"); // same as faker.js's faker.lorem.words()
faker.fake("{{name.lastName}} {{name.firstName}} lives in {{address.country}}");

Schema and API

By using fakeSchema and fakeApi, you can simply generate massive amount of json data for mockup REST API. Further more, you can fake schema nested by other schema.

const otherSchema = {id: "integer(1000,9000)", message: "phrase"};
const accountSchema = {
  message: "{{name.lastName}} {{name.firstName}} lives in {{address.country}}",
  money: "{{finance.amount}} millions USD",
  crypto: "finance.bitcoinAddress",
  nested: {
    prop1: "phrase", // schema-faker knows that phase belongs to hacker.phrase
    tags: ["word", "words(2,2)"],
    comments: [
      {commentId: "integer(1000,9999)", comment: "html(1,3)"},
      {commentId: "integer(100000,999999)", comment: "html(2,4)"}
    ],
    other: otherSchema
  }
};

faker.fakeSchema(accountSchema);
faker.fakeApi({
  "Users": userSchema,
  "Posts": {
    "id": "integer",
    "ref": otherSchema,
    "tags": ["word", "words(2,2)"],
    "comments": [otherSchema, otherSchema, otherSchema]
  },
  "Accounts": accountSchema
});

Custom Types

You can easily add your own custom type, and then define it in your schema. All type names are case-insensitive.

const categories = [
  faker.fake("string(6, 10)"),
  faker.fake("name"),
  faker.fake("words(2,3)"),
];
faker.addType("MyTax", () => {
  return faker.fakeInteger(1000,5000) * 21 / 100;
});
faker.addType("MyAccountSummary", (i,j) => {
  const rand = i + j;
  return "Debit: " + faker.fake("finance.amount") + " / Credit: " + rand.toString();
});
faker.addType("MyCategory", () => {
  return categories[faker.fakeInteger(0, categories.length - 1)];
});
faker.fake("MyCategory");
faker.fakeApi({
  "News": {
    "id": "integer",
    "title": "hacker.phrase",
    "content": "html(5,8)",
    "category": "mycategory", // great, I can add my own customized type
  },
  "Salaries": {
    "net": "integer(100000,120000)",
    "category": "mycategory", // great, I can add my own customized type
    "summary": "MyAccountSummary(500, 1000)", // type name is case-insensitive
    "tax": "mytax"  // wow, I can use as many customized types as I can
  }
});

Your Custom Mockup API Server

Your Custom Next.js Server

Developing a frontend app requires an API server, yet dealing browser CORS issue is troublesome. You can create your own custom Next.js server built with schema-faker to serve both frontend and (mockup) backend.

const path = require("path");
const next = require("next");
const express = require("express");
const { SchemaFaker, fakeRouter } = require("schema-faker");
const mockup = fakeRouter(path.resolve(__dirname, "schema.json"), {
  locale: "de",
});

const port = process.env.PORT || 3000;
const app = next({ dev: true });
const handle = app.getRequestHandler();

app
  .prepare()
  .then(() => {
    const server = express();
    const otherSchema = { id: "integer", message: "lorem.sentence" };

    server.use("/mockup/api", mockup); // simply use schema-faker's mockup router
    server.get("/:locale/other-fake-api", (req, res) => {
      const len = req.query.length || 10;
      const faker = new SchemaFaker(req.params.locale, len);
      const data = faker.fakeApi({ prop: otherSchema });
      res.json(data.prop);
    });

    server.all("*", (req, res) => {
      return handle(req, res);
    });

    server.listen(port, (err) => {
      if (err) throw err;
      console.log(
        `> Fake Server for Next.js is ready on http://localhost:${port}`
      );
    });
  })
  .catch((err) => {
    console.log("Error:::::", err);
  });

API Methods

Fake Methods

fake: faker.fake(dataType) to fake a single data type
fakeSchema: faker.fakeSchema(objectType) to fake a whole object
fakeApi: faker.fakeApi(apiSchema) to run mockup json-server

Data Types List

You can define your schema type with any type from the following types.

// schema.json
{
  "Api1": {
    "prop": "type",
    "prop": "type(min,max)"
  },
  "Api2": {
    "prop": "type",
    "prop": "group.type",
    "prop": "group.type(min,max)"
  }
}

integer
float
boolean
string
date
time
datetime
image
name
username
html
random.number
random.float
random.arrayElement
random.arrayElements
random.objectElement
random.uuid
random.boolean
random.word
random.words
random.image
random.locale
random.alpha
random.alphaNumeric
random.hexaDecimal
helpers.randomize
helpers.slugify
helpers.replaceSymbolWithNumber
helpers.replaceSymbols
helpers.replaceCreditCardSymbols
helpers.repeatString
helpers.regexpStyleStringParse
helpers.shuffle
helpers.mustache
helpers.createCard
helpers.contextualCard
helpers.userCard
helpers.createTransaction
name.firstName
name.lastName
name.middleName
name.findName
name.jobTitle
name.gender
name.prefix
name.suffix
name.title
name.jobDescriptor
name.jobArea
name.jobType
address.zipCode
address.zipCodeByState
address.city
address.cityPrefix
address.citySuffix
address.cityName
address.streetName
address.streetAddress
address.streetSuffix
address.streetPrefix
address.secondaryAddress
address.county
address.country
address.countryCode
address.state
address.stateAbbr
address.latitude
address.longitude
address.direction
address.cardinalDirection
address.ordinalDirection
address.nearbyGPSCoordinate
address.timeZone
animal.dog
animal.cat
animal.snake
animal.bear
animal.lion
animal.cetacean
animal.horse
animal.bird
animal.cow
animal.fish
animal.crocodilia
animal.insect
animal.rabbit
animal.type
company.suffixes
company.companyName
company.companySuffix
company.catchPhrase
company.bs
company.catchPhraseAdjective
company.catchPhraseDescriptor
company.catchPhraseNoun
company.bsAdjective
company.bsBuzz
company.bsNoun
finance.account
finance.accountName
finance.routingNumber
finance.mask
finance.amount
finance.transactionType
finance.currencyCode
finance.currencyName
finance.currencySymbol
finance.bitcoinAddress
finance.litecoinAddress
finance.creditCardNumber
finance.creditCardCVV
finance.ethereumAddress
finance.iban
finance.bic
finance.transactionDescription
image.image
image.avatar
image.imageUrl
image.abstract
image.animals
image.business
image.cats
image.city
image.food
image.nightlife
image.fashion
image.people
image.nature
image.sports
image.technics
image.transport
image.dataUri
lorem.word
lorem.words
lorem.sentence
lorem.slug
lorem.sentences
lorem.paragraph
lorem.paragraphs
lorem.text
lorem.lines
hacker.abbreviation
hacker.adjective
hacker.noun
hacker.verb
hacker.ingverb
hacker.phrase
internet.avatar
internet.email
internet.exampleEmail
internet.userName
internet.protocol
internet.httpMethod
internet.url
internet.domainName
internet.domainSuffix
internet.domainWord
internet.ip
internet.ipv6
internet.port
internet.userAgent
internet.color
internet.mac
internet.password
database.column
database.type
database.collation
database.engine
phone.phoneNumber
phone.phoneNumberFormat
phone.phoneFormats
date.past
date.future
date.between
date.betweens
date.recent
date.soon
date.month
date.weekday
time.recent
commerce.color
commerce.department
commerce.productName
commerce.price
commerce.productAdjective
commerce.productMaterial
commerce.product
commerce.productDescription
system.fileName
system.commonFileName
system.mimeType
system.commonFileType
system.commonFileExt
system.fileType
system.fileExt
system.directoryPath
system.filePath
system.semver
git.branch
git.commitEntry
git.commitMessage
git.commitSha
git.shortSha
vehicle.vehicle
vehicle.manufacturer
vehicle.model
vehicle.type
vehicle.fuel
vehicle.vin
vehicle.color
vehicle.vrm
vehicle.bicycle
music.genre
datatype.number
datatype.float
datatype.datetime
datatype.string
datatype.uuid
datatype.boolean
datatype.hexaDecimal
datatype.json
datatype.array

schema-faker

schema-faker

Getting started

CLI fake-server usage

CLI fake-data usage

Data Types

Basic Types

faker.js Types

Schema and API

Custom Types

Your Custom Mockup API Server

Your Custom Next.js Server

API Methods

Fake Methods

Data Types List

Readme

Keywords

Package Sidebar

Install

Repository

Homepage

Weekly Downloads

Version

License

Unpacked Size

Total Files

Last publish

Collaborators

schema-faker

schema-faker

Getting started

CLI fake-server usage

CLI fake-data usage

Data Types

Basic Types

faker.js Types

Schema and API

Custom Types

Your Custom Mockup API Server

Your Custom Next.js Server

API Methods

Fake Methods

Data Types List

Readme

Keywords

Package Sidebar

Install

Repository

Homepage

DownloadsWeekly Downloads

Version

License

Unpacked Size

Total Files

Last publish

Collaborators

Weekly Downloads