Oxidize

Oxidize is a library that makes assertions in tests easier to read and write.

Oxidize lets you set expected outcomes on objects in unit tests (or anywhere). This allows for more fluid expression than with assertions alone and yields more readable error messages.

For example:

use oxidize::dsl::*;

expect("optimus prime").to(contain("prime"));

Any expectation can also be negated:

use oxidize::dsl::*;

expect("megatron").to_not(contain("prime"));

Built-in Matchers

Oxidize has of built-in matchers that you can use for all kinds of data.

Equality

use oxidize::dsl::*;

expect(1).to(equal(1));
expect(6).is(greater_than(0));
expect(-120).is(less_than(5));

Truthiness

use oxidize::dsl::*;

struct Transformer { is_prime: bool };
let optimus = Transformer { is_prime: true };

expect(optimus.is_prime).to(be_true());

struct Paradox;
impl Paradox {
    fn can_fly(&self) -> bool {
        false
    }
}
let pigs = Paradox;

expect(pigs.can_fly()).to(be_false());

Substrings / Containers

use oxidize::dsl::*;

expect(vec![1, 2, 3]).to(contain(2));
expect("Energon Cube").to(contain("Cube"));

Length

use oxidize::dsl::*;

expect(vec![1, 2, 3, 4]).is_not(empty());

Options / Existence

use oxidize::dsl::*;

let mut big: Vec<u64> = vec![1337u64];

expect(big.pop()).is(some());
expect(big.pop()).is(none());

Regex

use oxidize::dsl::*;

expect("sam").to(match_regex("..."));

Inspiration

These projects were inspirational in oxidize's design (maybe they'll inspire you, too!):

• rspec-expectations
• hamcrest
• assertj