Is there a way to make generated data optional?

[lexuzieel]

Sometimes it is useful to generate randomly optional fields, such as the last name (but really - almost any field).

Is it possible to do something like this:

firstName := faker.FirstName()
lastName := faker.Optional(.5).LastName() // <-- Generate non-empty last name 50% of the time

fullName := firstName
if lastName != "" {
    fullName += " " + lastName
}

println("Hello, " + fullName + "!")

Here faker.LastName() would return empty string 50% of the time.

[bxcodec]

Is it possible to use a custom generator faker for that?

ref

faker/faker.go

Lines 405 to 456 in 72e5223

	// AddProvider extend faker with tag to generate fake data with specified custom algorithm
	// Example:
	// type Gondoruwo struct {
	// Name string
	// Locatadata int
	// }
	//
	// type Sample struct {
	// ID int64 `faker:"customIdFaker"`
	// Gondoruwo Gondoruwo `faker:"gondoruwo"`
	// Danger string `faker:"danger"`
	// }
	//
	// func CustomGenerator() {
	// // explicit
	// faker.AddProvider("customIdFaker", func(v reflect.Value) (interface{}, error) {
	// return int64(43), nil
	// })
	// // functional
	// faker.AddProvider("danger", func() faker.TaggedFunction {
	// return 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)
	// }
	//
	// Will print
	// {ID:43 Gondoruwo:{Name:Power Locatadata:324} Danger:danger-ranger}
	// Notes: when using a custom provider make sure to return the same type as the field
	func AddProvider(tag string, provider TaggedFunction) error {
	if _, ok := mapperTag[tag]; ok {
	return errors.New(ErrTagAlreadyExists)
	}
	PriorityTags = append(PriorityTags, tag)
	mapperTag[tag] = provider
	return nil
	}