aeneasr/faker

Go (Golang) Fake Data Generator for Struct

Docs

faker

Struct Data Fake Generator

Faker will generate you a fake data based on your Struct.

Index

• Support
• Getting Started
• Example
• Limitation
• Contribution

Support

You can file an Issue. See documentation in Godoc

Getting Started

Download

go get -u github.com/bxcodec/faker

Example

With Tag

Supported tag:

Internet :

• Email
• Mac address
• Domain name
• URL
• UserName
• IP Address (IPv4, IPv6 )
• Password

Payment :

• Credit Card Type (VISA, MASTERCARD, AMERICAN EXPRESS, DISCOVER, JCB, DINERS CLUB)
• Credit Card Number

Address :

• Latitude and Longitude

Phone :

• Phone number
• Toll free phone number
• E164PhoneNumber

Person :

• Title male
• Title female
• FirstName
• FirstName male
• FirstName female
• LastName
• Name

DateTime :

• UnixTime
• Date
• Time
• MonthName
• Year
• DayOfWeek
• DayOfMonth
• Timestamp
• Century
• TimeZone
• TimePeriod

Lorem :

• Word
• Sentence
• Paragraph

Price :

• Currency
• Amount
• Amount with Currency

UUID :

• UUID Digit (32 bytes)
• UUID Hyphenated (36 bytes)

Skip :

• -

package main

import (
	"fmt"

	"github.com/bxcodec/faker"
)

// SomeStruct ...
type SomeStruct struct {
	Latitude           float32 `faker:"lat"`
	Longitude          float32 `faker:"long"`
	CreditCardNumber   string  `faker:"cc_number"`
	CreditCardType     string  `faker:"cc_type"`
	Email              string  `faker:"email"`
	IPV4               string  `faker:"ipv4"`
	IPV6               string  `faker:"ipv6"`
	Password           string  `faker:"password"`
	PhoneNumber        string  `faker:"phone_number"`
	MacAddress         string  `faker:"mac_address"`
	URL                string  `faker:"url"`
	UserName           string  `faker:"username"`
	TollFreeNumber     string  `faker:"toll_free_number"`
	E164PhoneNumber    string  `faker:"e_164_phone_number"`
	TitleMale          string  `faker:"title_male"`
	TitleFemale        string  `faker:"title_female"`
	FirstName          string  `faker:"first_name"`
	FirstNameMale      string  `faker:"first_name_male"`
	FirstNameFemale    string  `faker:"first_name_female"`
	LastName           string  `faker:"last_name"`
	Name               string  `faker:"name"`
	UnixTime           int64   `faker:"unix_time"`
	Date               string  `faker:"date"`
	Time               string  `faker:"time"`
	MonthName          string  `faker:"month_name"`
	Year               string  `faker:"year"`
	DayOfWeek          string  `faker:"day_of_week"`
	DayOfMonth         string  `faker:"day_of_month"`
	Timestamp          string  `faker:"timestamp"`
	Century            string  `faker:"century"`
	TimeZone           string  `faker:"timezone"`
	TimePeriod         string  `faker:"time_period"`
	Word               string  `faker:"word"`
	Sentence           string  `faker:"sentence"`
	Paragraph          string  `faker:"paragraph"`
	Currency           string  `faker:"currency"`
	Amount             float64 `faker:"amount"`
	AmountWithCurrency string  `faker:"amount_with_currency"`
	UUIDHypenated	   string  `faker:"uuid_hyphenated"`
	UUID	           string  `faker:"uuid_digit"`
	Skip		   string  `faker:"-"`
}

func main() {

	a := SomeStruct{}
	err := faker.FakeData(&a)
	if err != nil {
		fmt.Println(err)
	}
	fmt.Printf("%+v", a)
	/*
		Output  :
		{
			Latitude: 81.12195
			Longitude: -84.38158
			CreditCardType: American Express
			CreditCardNumber: 373641309057568
			Email: mJBJtbv@OSAaT.ru
			IPV4: 99.23.42.63
			IPV6: 975c:fb2c:2133:fbdd:beda:282e:1e0a:ec7d
			Password: dfJdyHGuVkHBgnHLQQgpINApynzexnRpgIKBpiIjpTPOmNyMFb
			PhoneNumber: 792-153-4861
			MacAddress: cd:65:e1:d4:76:c6
			URL: https://www.oEuqqAY.org/QgqfOhd
			UserName: lVxELHS
			TollFreeNumber: (777) 831-964572
			E164PhoneNumber: +724891571063
			TitleMale: Mr.
			TitleFemale: Queen
			FirstName: Whitney
			FirstNameMale: Kenny
			FirstNameFemale: Jana
			LastName: Rohan
			Name: Miss Casandra Kiehn
			UnixTime: 1197930901
			Date: 1982-02-27
			Time: 03:10:25
			MonthName: February
			Year: 1996
			DayOfWeek: Sunday
			DayOfMonth: 20
			Timestamp: 1973-06-21 14:50:46
			Century: IV
			TimeZone: Canada/Eastern
			TimePeriod: AM
			Word: nesciunt
			Sentence: Consequatur perferendis aut sit voluptatem accusantium.
			Paragraph: Aut consequatur sit perferendis accusantium voluptatem. Accusantium perferendis consequatur voluptatem sit aut. Aut sit accusantium consequatur voluptatem perferendis. Perferendis voluptatem aut accusantium consequatur sit.
			Currency: IRR,
			Amount: 88.990000,
			AmountWithCurrency: XBB 49257.100000,
			UUIDHypenated: 8f8e4463-9560-4a38-9b0c-ef24481e4e27,
			UUID: 90ea6479fd0e4940af741f0a87596b73,
			Skip:
		}
	*/
}

Custom Generator Provider

You can also add your own generator function to your own defined tags. See example below

type Gondoruwo struct {
	Name       string
	Locatadata int
}

type Sample struct {
	ID                 int64     `faker:"customIdFaker"`
	Gondoruwo          Gondoruwo `faker:"gondoruwo"`
	Danger             string    `faker:"danger"`
}

func CustomGenerator() {
	faker.AddProvider("customIdFaker", func(v reflect.Value) (interface{}, error) {
		 return int64(43), nil
	})
	faker.AddProvider("danger", func(v reflect.Value) (interface{}, error) {
		return "danger-ranger", nil
	})

	faker.AddProvider("gondoruwo", func(v reflect.Value) (interface{}, error) {
		obj := Gondoruwo{
			Name:       "Power",
			Locatadata: 324,
		}
		return obj, nil
	})
}

func main() { 
	CustomGenerator()
	var sample Sample
	faker.FakeData(&sample)
	fmt.Printf("%+v", sample)
}

Results:

{ID:43 Gondoruwo:{Name:Power Locatadata:324} Danger:danger-ranger}

Length And Boundary

You can set length for your random strings also set boundary for your integers.

package main

import (
	"fmt"

	"github.com/bxcodec/faker"
)

type SomeStruct struct {
	Inta  int   `faker:"boundary_start=5, boundary_end=10"`
	Int8  int8  `faker:"boundary_start=100, boundary_end=1000"`
	Int16 int16 `faker:"boundary_start=123, boundary_end=1123"`
	Int32 int32 `faker:"boundary_start=-10, boundary_end=8123"`
	Int64 int64 `faker:"boundary_start=31, boundary_end=88"`

	UInta  uint   `faker:"boundary_start=35, boundary_end=152"`
	UInt8  uint8  `faker:"boundary_start=5, boundary_end=1425"`
	UInt16 uint16 `faker:"boundary_start=245, boundary_end=2125"`
	UInt32 uint32 `faker:"boundary_start=0, boundary_end=40"`
	UInt64 uint64 `faker:"boundary_start=14, boundary_end=50"`

	ASString []string          `faker:"len=50"`
	SString  string            `faker:"len=25"`
	MSString map[string]string `faker:"len=30"`
	MIint    map[int]int       `faker:"boundary_start=5, boundary_end=10"`
}

func main(){
    faker.SetRandomMapAndSliceSize(20) //Random generated map or array size wont exceed 20...
	a := SomeStruct{}
	err := faker.FakeData(&a)
	if err != nil {
		fmt.Println(err)
	}
	fmt.Printf("%+v", a)
}

Result:

{
    Inta:7
    Int8:-102
    Int16:556
    Int32:113
    Int64:70
    UInta:78
    UInt8:54
    UInt16:1797
    UInt32:8
    UInt64:34
    ASString:[
        geHYIpEoQhQdijFooVEAOyvtTwJOofbQPJdbHvEEdjueZaKIgI
        WVJBBtmrrVccyIydAiLSkMwWbFzFMEotEXsyUXqcmBTVORlkJK
        xYiRTRSZRuGDcMWYoPALVMZgIXoTQtmdGXQfbISKJiavLspuBV
        qsoiYlyRbXLDAMoIdQhgMriODYWCTEYepmjaldWLLjkulDGuQN
        GQXUlqNkVjPKodMebPIeoZZlxfhbQJOjHSRjUTrcgBFPeDZIxn
        MEeRkkLceDsqKLEJFEjJxHtYrYxQMxYcuRHEDGYSPbELDQLSsj
        tWUIACjQWeiUhbboGuuEQIhUJCRSBzVImpYwOlFbsjCRmxboZW
        ZDaAUZEgFKbMJoKIMpymTreeZGWLXNCfVzaEyWNdbkaZOcsfst
        uwlsZBMlEknIBsALpXRaplZWVtXTKzsWglRVBpmfsQfqraiEYA
        AXszbzsOzYPYeXHXRwoPmoPoBxopdFFvWMBTPCxESTepRpjlnB
        kTuOPHlUrSzUQRmZMYplWbyoBbWzQYCiydyzurOduhjuyiGrCE
        FZbeLMbelIeCMnixknIARZRbwALObGXADQqianJbkiEAqqpdnK
        TiQrZbnkvxEciyKXlliUDOGVdpMoAsHSalFbLcYyXxNFLAhqjy
        KlbjbloxkWKSqvUfJQPpFLoddWgeABfYUoaAnylKmEHwxgNsnO
        ]
    SString:VVcaPSFrOPYlEkpVyTRbSZneB
    MSString:map[
        ueFBFTTmqDwrXDoXAYTRhQRmLXhudA:AhQewvZfrlytbAROzGjpXUmNQzIoGl
        fZwrCsFfZwqMsDJXOUYIacflFIeyFU:VMufFCRRHTtuFthOrRAMbzbKVJHnvJ
        rHDQTyZqZVSPLwTtZfNSwKWrgmRghL:lRSXNHkhUyjDuBgoAfrQwOcHYilqRB
        BvCpQJMHzKXKbOoAnTXkLCNxKshwWr:tiNFrXAXUtdywkyygWBrEVrmAcAepD
        uWWKgHKTkUgAZiopAIUmgVWrkrceVy:GuuDNTUiaBtOKwWrMoZDiyaOPxywnq
        HohMjOdMDkAqimKPTgdjUorydpKkly:whAjmraukcZczskqycoJELlMJTghca
        umEgMBGUvBptdKImKsoWXMGJJoRbgT:tPpgHgLEyHmDOocOiSgTbXQHVduLxP
        SRQLHjBXCXKvbLIktdKeLwMnIFOmbi:IJBpLyTcraOxOUtwSKTisjElpulkTL
        dbnDeJZLqMXQGjbTSNxPSlfDHGCghU:JWrymovFwNWbIQBxPpQmlgJsgpXcui
        roraKNGnBXnrJlsxTnFgxHyZeTXdAC:XIcLWqUAQAbfkRrgfjrTVxZCvRJXyl
        TrvxqVVjXAboYDPvUglSJQrltPjzLx:nBhWdfNPybnNnCyQlSshWKOnwUMQzL
        dTHhWJWMwfVvKpIKTFCaoBJgKmnfbD:ixjNHsvSkRkFiNLpgUzIKPsheqhCeY
        lWyBrtfcGWiNbSTJZJXwOPvVngZZMk:kvlYeGgwguVtiafGKjHWsYWewbaXte
        bigsYNfVcNMGtnzgaqEjeRRlIcUdbR:hYOnJupEOvblTTEYzZYPuTVmvTmiit
        ]
    MIint:map[7:7 5:7 8:8 9:5 6:5]
}

Without Tag

You also can use faker to generate your structs data randomly without any tag. And it will fill the data based on its data-type.

package main

import (
	"fmt"

	"github.com/bxcodec/faker"
)

type SomeStruct struct {
	Int      int
	Int8     int8
	Int16    int16
	Int32    int32
	Int64    int64
	String   string
	Bool     bool
	SString  []string
	SInt     []int
	SInt8    []int8
	SInt16   []int16
	SInt32   []int32
	SInt64   []int64
	SFloat32 []float32
	SFloat64 []float64
	SBool    []bool
	Struct   AStruct
}
type AStruct struct {
	Number        int64
	Height        int64
	AnotherStruct BStruct
}

type BStruct struct {
	Image string
}

func main() {

	a := SomeStruct{}
	err := faker.FakeData(&a)
	if err != nil {
		fmt.Println(err)
	}
	fmt.Printf("%+v", a)
	/*
		Output:
		{
		    Int:5231564546548329
		    Int8:52
		    Int16:8
		    Int32:2046951236
		    Int64:1486554863682234423
		    String:ELIQhSfhHmWxyzRPOTNblEQsp
		    Bool:false
		    SString:[bzYwplRGUAXPwatnpVMWSYjep zmeuJVGHHgmIsuyWmLJnDmbTI FqtejCwoDyMBWatoykIzorCJZ]
		    SInt:[11661230973193 626062851427 12674621422454 5566279673347]
		    SInt8:[12 2 58 22 11 66 5 88]
		    SInt16:[29295225 8411281 69902706328]
		    SInt32:[60525685140 2733640366211 278043484637 5167734561481]
		    SInt64:[81684520429188374184 9917955420365482658170 996818723778286568 163646873275501565]
		    SFloat32:[0.556428 0.7692596 0.6779895 0.29171365 0.95445055]
		    SFloat64:[0.44829454895586585 0.5495675898536803 0.6584538253883265]
		    SBool:[true false true false true true false]
		    Struct:{
		        Number:1
		        Height:26
		        AnotherStruct:{
		            Image:RmmaaHkAkrWHldVbBNuQSKlRb
		        }
		    }
		}
	*/
}

DEMO

Benchmark

Bench To Generate Fake Data

Without Tag

BenchmarkFakerDataNOTTagged-4             500000              3049 ns/op             488 B/op         20 allocs/op

Using Tag

 BenchmarkFakerDataTagged-4                100000             17470 ns/op             380 B/op         26 allocs/op

MUST KNOW

The Struct Field must PUBLIC.
Support Only For :

• int int8 int16 int32 int64
• []int []int8 []int16 []int32 []int64
• bool []bool
• string []string
• float32 float64 []float32 []float64
• Nested Struct Field
• time.Time []time.Time

Limitation

Unfortunately this library has some limitation

• It does not support private fields. Make sure your structs fields you intend to generate fake data for are public, it would otherwise trigger a panic. You can however omit fields using a tag skip faker:"-" on your private fields.
• It does not support the interface{} data type. How could we generate anything without knowing its data type?
• It does not support the map[interface{}]interface{}, map[any_type]interface{}, map[interface{}]any_type data types. Once again, we cannot generate values for an unknown data type.
• Custom types are not fully supported. However some custom types are already supported: we are still investigating how to do this the correct way. For now, if you use faker, it's safer not to use any custom types in order to avoid panics.

Contribution

To contrib to this project, you can open a PR or an issue.

Maintainer

• Iman Tumorang
  
• Ilya