How to generate mock test data using Go

Realistic and reliable test data plays a key role in ensuring the quality and functionality of the application. Generating mock data that simulates a real-life scenario is a useful skill for many forms of testing.

There is no support for creating dummy data in the standard library, but many packages exist in Go's broader ecosystem. A popular package for generating dummy data is Gofakeit.

Get started with Gofakeit

Gofakeit is a package that generates dummy data in a Go program. Gofakeit provides rich features, including random data generation that accesses different types. It also offers customization options to adhere to specific formatting standards, localization support and real-time & date generation.

Run this command in your project's working directory, then you have instantiated a new Go project, to add Gofakeit as a third-party dependency:

go get github.com/brianvoe/gofakeit/v6

After adding Gofakeit as a dependency you can import the package as follows:

import ( "github.com/brianvoe/gofakeit/v6" )

Overall, Gofakeit provides most of the functionality of the dummy data generation package.

Generate fake data with Gofakeit

Gofakeit provides functionality to create different data types, including name, email, phone, and business stages…

Here's how you can create dummy data using Gofakeit:

package main import ( "fmt" "github.com/brianvoe/gofakeit/v6" ) func main() { // Tạo tên giả name := gofakeit.Name() fmt.Println("Name:", name) // Tạo địa chỉ email giả email := gofakeit.Email() fmt.Println("Email:", email) // Tạo số điện thoại giả phone := gofakeit.Phone() fmt.Println("Phone:", phone) // Tạo tên công ty giả company := gofakeit.Company() fmt.Println("Company:", company) // Tạo số thẻ tín dụng giả creditCard := gofakeit.CreditCardNumber() fmt.Println("Credit Card:", creditCard) // Tạo giai đoạn hacker giả hackerPhrase := gofakeit.HackerPhrase() fmt.Println("Hacker Phrase:", hackerPhrase) // Tạo tên công việc giả jobTitle := gofakeit.JobTitle() fmt.Println("Job Title:", jobTitle) // Tạo ký hiệu viết tắt tiền tệ giả currency := gofakeit.CurrencyShort() fmt.Println("Currency:", currency) }

The main function generates some dummy values ​​using Gofakeit and prints them to the console using the Println function from the fmt package .

Gofakeit provides struct tags to generate dummy data for different fields. When using the struct tag, Gofakeit initializes the fields with dummy data.

import ( "fmt" "time" "github.com/brianvoe/gofakeit/v6" ) type Person struct { ID string `fake:"{uuid}"` FirstName string `fake:"{firstname}"` LastName string `fake:"{lastname}"` Age int `fake:"{number:18,60}"` Email string `fake:"{email}"` Address string `fake:"{address}"` CreatedAt time.Time `fake:"{date}"` } func main() { var person Person gofakeit.Struct(&person) fmt.Printf("ID: %sn", person.ID) fmt.Printf("First Name: %sn", person.FirstName) fmt.Printf("Last Name: %sn", person.LastName) fmt.Printf("Age: %dn", person.Age) fmt.Printf("Email: %sn", person.Email) fmt.Printf("Address: %sn", person.Address) fmt.Printf("Created At: %sn", person.CreatedAt) }

The fields of struct Person all have a dummy struct tag. In the main function, the variable person is an instance of the struct Person.

The gofakeit.Struct method fills the exported elements of a struct with random data based on the value of the fake tag of the exported fields. The main function then prints the struct fields to the console.

Generate complex dummy data

You can generate complex pseudo-data using Gofakeit, consisting of random sentences, paragraphs, and lorem ipsums with the Sentence , Paragraph , and LoremIpsumParagraph functions respectively .

package main import ( "fmt" "github.com/brianvoe/gofakeit/v6" ) func generateRandomSentence() string { // Tạo câu ngẫu nhiên bằng 6 từ sentence := gofakeit.Sentence(6) return sentence } func generateRandomParagraph() string { // Tạo đoạn ngẫu nhiên bằng 3 câu, mỗi câu có từ 4 tới 8 từ paragraph := gofakeit.Paragraph(3, 4, 8, "/n") return paragraph } func generateLoremIpsum() string { // Tạo 2 đoạn text lorem ipsum, mỗi đoạn có từ 3 tới 5 câu loremIpsum := gofakeit.LoremIpsumParagraph(3, 5, 12, "n") return loremIpsum } func main() { // Thiết lập seed ngẫu nhiên cho kết quả nhất quán (tùy chọn) gofakeit.Seed(0) // Tạo và in câu ngẫu nhiên fmt.Println("Random Sentence:") fmt.Println(generateRandomSentence()) // Tạo và in đoạn ngẫu nhiên fmt.Println("nRandom Paragraph:") fmt.Println(generateRandomParagraph()) // Tạo và in text lorem ipsum fmt.Println("nLorem Ipsum Text:") fmt.Println(generateLoremIpsum()) }

The generateRandomSentence function generates a random sentence with Gofakeit's Sentence function. The generateRandomParagraph function generates a random fragment with the Paragraph function.

The generateLoremIpsum function generates a random lorem ipsum with the LoremIpsumParagraph function.

The main function calls generateRandomSentence , generateRandomParagraph , and generateLoremIpsum . This function prints the results to the console.

Gofakeit simplifies the testing process by generating dynamic data to ensure the ability to meet different requirements. Hope this article helps you better understand this process.

Jessica Tanner

Update 11 August 2023