Crate fake

source ·
Expand description

A library for generating fake data.

Feature flags

  • derive provides #[derive(Dummy)]
  • chrono chrono integration
  • http http integration
  • uuid uuid integration

Usage

use fake::{Dummy, Fake, Faker};
use rand::rngs::StdRng;
use rand::SeedableRng;

#[derive(Debug, Dummy)]
pub struct Foo {
    #[dummy(faker = "1000..2000")]
    order_id: usize,
    customer: String,
    paid: bool,
}

// type derived Dummy
let f: Foo = Faker.fake();
println!("{:?}", f);

// using `Faker` to generate default fake value of given type
let tuple = Faker.fake::<(u8, u32, f32)>();
println!("tuple {:?}", tuple);
println!("String {:?}", Faker.fake::<String>());

// types U can used to generate fake value T, if `T: Dummy<U>`
println!("String {:?}", (8..20).fake::<String>());
println!("u32 {:?}", (8..20).fake::<u32>());

// using `faker` module with locales
use fake::faker::name::raw::*;
use fake::locales::*;

let name: String = Name(EN).fake();
println!("name {:?}", name);

let name: String = Name(ZH_TW).fake();
println!("name {:?}", name);

// using convenient function without providing locale
use fake::faker::lorem::en::*;
let words: Vec<String> = Words(3..5).fake();
println!("words {:?}", words);

// Using a tuple config list to generate a vector with a length range and a specific faker for the element
let name_vec: Vec<String> = (Name(EN), 3..5).fake();

// Using a macro as an alternative method for the tuple config list
let name_vec = fake::vec![String as Name(EN); 3..5];

// using macro to generate nested collection
let name_vec = fake::vec![String as Name(EN); 4, 3..5, 2];
println!("random nested vec {:?}", name_vec);

// fixed seed rng
let seed = [
    1, 0, 0, 0, 23, 0, 0, 0, 200, 1, 0, 0, 210, 30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0,
];
let ref mut r = StdRng::from_seed(seed);
for _ in 0..5 {
    let v: usize = Faker.fake_with_rng(r);
    println!("value from fixed seed {}", v);
}

// Use an always true RNG so that optional types are always `Some` values. (Requires
// always-true-rng feature).
use fake::utils::AlwaysTrueRng;
let mut rng = AlwaysTrueRng::default();
let result: Option<i64> = Faker.fake_with_rng(&mut rng);
println!("Always Some: {}", result.unwrap());

Modules

Macros

Structs

Traits

  • Provide data structure a way to generate fake values. The opposite of Fake.
  • Generate fake values given a type that implements Dummy. The opposite of Dummy.

Derive Macros

  • Derive macro generating an impl of the trait Dummy. This works for both structs and enums.