beaver: A Rust repository from TaKO8Ki

beaver is a library for setting up Rust objects inspired by factory_bot.

Dependencies

[dependencies]
beaver = "1"
serde = { version = "1.0", features = ["derive"] }

If you want to use chrono for your struct fields, Cargo.toml would look like this.

[dependencies]
beaver = "1"
serde = { version = "1.0", features = ["derive"] }
# you need `serde` feature.
chrono = { version = "0.4", features = ["serde"] }

Usage

Quickstart

use serde::{Deserialize, Serialize};

// `Post` needs both of `Serialize` and `Deserialize`.
#[derive(Serialize, Deserialize, Debug)]
struct Post {
    id: u16,
    title: String,
    approved: bool,
}

beaver::define! {
    PostFactory (Post) {
        id -> |n| n,
        title -> |n| format!("post-{}", n),
        approved -> |_| false,
    }
}

fn main() {
    let post_factory = PostFactory::new();
    let post1 = post_factory.build(|_| {});
    let post2 = post_factory.build(|_| {});
    println!("{:?}", post1);
    println!("{:?}", post2);
}

Define a factory

beaver::define! {
    // [factory name] (struct)
    PostFactory (Post) {
        // `n` is a sequence number.
        id -> |n| n,
        title -> |n| format!("{}", n),
        approved -> |_| false,
    }
}

This define! macro defines a struct, PostFactory as a factory. If you want to use factories outside modules, you need to make both of factories and structs public. For more information, please see this example.

Build structs

// initialize a factory.
let post_factory = PostFactory::new();

// build a `Post`.
post_factory.build(|_| {});

// build a vector of some `Posts`.
post_factory.build_list(3, |_| {});

// override attributes of a factory.
post_factory.build(|post| {
    post.id = 1024;
    post.title = "foo bar".to_string()
});

Public factory

use chrono::NaiveDateTime;
use serde::{Deserialize, Serialize};

// `Post` needs to be public.
#[derive(Serialize, Deserialize, Debug)]
pub struct Post {
    id: u16,
    title: String,
    approved: bool,
    created_at: NaiveDateTime,
}

mod factory {
    use crate::Post;
    use chrono::NaiveDate;

    beaver::define! {
        // `PostFactory` needs to be public.
        pub PostFactory (Post) {
            id -> |n| n,
            title -> |n| format!("post-{}", n),
            approved -> |_| false,
            created_at -> |_| NaiveDate::from_ymd(2020, 1, 1).and_hms(0, 0, 0),
        }
    }
}

fn main() {
    use factory::PostFactory;

    let post_factory = PostFactory::new();
    let post1 = post_factory.build(|_| {});
    let post2 = post_factory.build(|_| {});
    println!("{:?}\n{:?}", post1, post2);
}

Output:

Post { id: 1, title: "post-1", approved: false, created_at: 2020-01-01T00:00:00 }
Post { id: 2, title: "post-2", approved: false, created_at: 2020-01-01T00:00:00 }

Sub factory vector

use serde::{Deserialize, Serialize};

#[derive(Serialize, Deserialize, Debug)]
pub struct Post {
    id: u16,
    title: String,
    approved: bool,
    tags: Vec<Tag>,
}

#[derive(Serialize, Deserialize, Debug)]
pub struct Tag {
    id: u16,
    name: String,
}

mod factory {
    use crate::Post;
    use crate::Tag;

    beaver::define! {
        pub PostFactory (Post) {
            id -> |n| n,
            title -> |n| format!("post-{}", n),
            approved -> |_| true,
            // use `build_list`
            tags -> |n| TagFactory::build_list(3, n),
        }
    }

    beaver::define! {
        TagFactory (Tag) {
            id -> |n| beaver::sequence(100, n),
            name -> |n| format!("tag-{}", n),
        }
    }
}

fn main() {
    use factory::PostFactory;

    let post_factory = PostFactory::new();
    let post1 = post_factory.build(|_| {});
    let post2 = post_factory.build(|_| {});
    println!("{:?}\n{:?}", post1, post2);

    let posts = post_factory.build_list(3, |_| {});
    for post in posts {
        println!("{:?}", post);
    }
}

Output:

Post { id: 1, title: "post-1", approved: true, tags: [Tag { id: 1, name: "tag-1" }, Tag { id: 2, name: "tag-2" }, Tag { id: 3, name: "tag-3" }] }
Post { id: 2, title: "post-2", approved: true, tags: [Tag { id: 4, name: "tag-4" }, Tag { id: 5, name: "tag-5" }, Tag { id: 6, name: "tag-6" }] }
Post { id: 3, title: "post-3", approved: true, tags: [Tag { id: 7, name: "tag-7" }, Tag { id: 8, name: "tag-8" }, Tag { id: 9, name: "tag-9" }] }
Post { id: 4, title: "post-4", approved: true, tags: [Tag { id: 10, name: "tag-10" }, Tag { id: 11, name: "tag-11" }, Tag { id: 12, name: "tag-12" }] }
Post { id: 5, title: "post-5", approved: true, tags: [Tag { id: 13, name: "tag-13" }, Tag { id: 14, name: "tag-14" }, Tag { id: 15, name: "tag-15" }] }

TaKO8Ki/beaver