power-assert-rs

Power Assert in Rust. Provides better assertion message like this:

$ cargo run --example test -v Fresh power-assert v0.1.0 (file:///home/nksm/repos/gifnksm/power-assert-rs) Running `target/debug/examples/test` power_assert!(bar.val == bar.foo.val) | | | | | | | 3 | | | 2 | | | Foo { val: 2 } | | Bar { val: 3, foo: Foo { val: 2 } } | false Bar { val: 3, foo: Foo { val: 2 } } thread '<main>' panicked at 'assertion failed: bar.val == bar.foo.val', examples/test.rs:26 Process didn't exit successfully: `target/debug/examples/test` (exit code: 101)

How to use

Add this to your Cargo.toml:

toml [dependencies] power-assert = "*"

and add this to your lib.rs or main.rs:

```rust

![feature(plugin)]

![plugin(power_assert)]

```

Now, you can use power_assert!() and power_assert_eq!().

If you want to override builtin assert!() and assert_eq!(), change your lib.rs or main.rs as follows.

```rust

![feature(plugin)]

![plugin(powerassert(overridebuiltins))]

```

Known problems

The following assersions fail to compile with power-assert.

rust fn foo() -> i32 { 1 } power_assert!(foo() == 1);