snaptest

Dead simple snapshot testing (inspired by jest).

Documentation (including this README) is a work in progress. Feel free to submit an issue if you have a question about usage.

Features

• Any type that implements Debug can be returned from a test.
• First class integration with failure.
• The snapshot store is thread safe so your tests can run in parallel.
• Beautiful diffs are printed when a snapshot test fails.
• A single small binary file is used to store snapshots.

TODO

Installation

First, add snaptest to the dependencies section of your Cargo.toml:

[dependencies]
snaptest = "0.1"

Next, add the following snippet to the entry point of your crate (lib.rs or main.rs):

#[macro_use]
extern crate snaptest;

Usage

Derive Debug on types that you want to use with snaptest:

use std::str::FromStr;

#[derive(Debug)]
pub struct User {
    connection: Connection,
    name: String,
}

#[derive(Debug)]
pub enum Connection {
    Online,
    Offline,
}

impl FromStr for User {
  // ...
}

Now, in the test module for the User struct:

snaptest!{
    fn parse_user() -> Result<User, Error> {
        "Zak:online".parse()
    }
}

Next time your test runs, a snapshot will be added to a local .snapfile to compare against future test results. If you get a different result back than what matches the snapshot, the test will fail and the diff will be printed to the console.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.