Rand derive 2

Derive macro for generating random types with the rand crate. It will implement the rand::distributions::Standard for a given type.

Usage

Check out the example crate or follow the instructions below.

Add this to your Cargo.toml file:

[dependencies]
rand-derive = "0.1"
rand = "0.7"

Import the macro somewhere in your file where your type is:

use rand_derive2::RandGen;

Alternatively, use this to global import the macro:

#[macro_use]
extern crate rand_derive2;

Add the RandGen derive macro for your type:

#[derive(RandGen)]
struct MyStruct {}

Generate your struct:

fn generate_my_struct() -> MyStruct { 
    rand::random()
}

// Or like this
fn generate_my_struct_direct() -> MyStruct { 
    MyStruct::generate_random()
}

Customization

Note: all things that can be customized is covered in the example crate

Options

To make sure an option is never generated with None, add the always_some attribute on top of the property. To make sure an option is never generated with Some, add the always_none attribute on top of the property.

Skip enum variant

If a variant should never be generated, add the skip_variant attribute on the variant.

Custom value

If you want a custom value for one of the properties, add the custom_rand attribute. A trait is created called TestDataProviderFor$TYPE$. This trait will require the user to provider the values.

No rand

Panic implementation of the property, making the type unable to be random generated. Note: place #[allow(unreachable_code)] above your type to omit compiler warnings.

Default_rand

Place default_rand above a type to make it generate the default value.

How it works

Structs

It calls rng.gen() on all the fields.

Enums

It will generate a random variant.

TODO

Recursion for e.g. vec in vec
More types from the standard library covered
Functions documented
Custom trait type/method names
Weighted randomization (currently only supports rand::distributions::Standard)

rand_derive2 0.1.9