expectest

Crate provides matchers and matcher functions for unit testing. Inspired by Nimble for Swift.

Using this library you will receive nice messages with data that used in test case, example:

let result = vec![1, 2, 2];
expect!(result).to(be_equal_to([1, 2, 3]));

Test fails and gives us a message:

expected to be equal to <[1, 2, 3]>, got <[1, 2, 2]>

Note: You need to use cargo test -- --nocapture to see output from tests.

In Cargo.toml:

[dev-dependencies]
expectest = "*"

In your crate:

#[cfg(test)]
#[macro_use(expect)]
extern crate expectest;

You can export all needed functions and types from prelude module:

use expectest::prelude::*;

Use basic syntax to express expectations:

expect!(...).to(...);
expect!(...).to_not(...);
expect!(...).not_to(...);

Note: You can use expect function instead of expect! macro in that case you will not see file and line where the test fails.

For types that implement the PartialEq trait:

expect!("hello".to_string()).to(be_equal_to("hello"));

There is a way to check if two float numbers are close each other:

expect!(12.1_f64).to(be_close_to(12.0).delta(0.1));

With default delta equal 0.001:

expect!(12.001_f64).to(be_close_to(12.0));

For types that implement the PartialOrd trait:

expect!(1).to(be_greater_than(0));

Use following matchers: be_less_than, be_less_or_equal_to, be_greater_than, be_greater_or_equal_to

There are matchers for the Option<T> type:

expect!(Some(9)).to(be_some().value(9));

Use following matchers: be_some, be_none

There are matchers for the Result<T, E> type:

expect!("4".parse::<u32>()).to(be_ok().value(4));

Use following matchers: be_ok, be_err

There is be_empty matcher for types that implement IsEmpty trait:

expect!("").to(be_empty());

Note: IsEmpty trait implemented by library for following types: String, &str, Vec<T>, &[T].

expect!(9 == 9).to(be_true());

Use following matchers: be_true, be_false

License

MIT