| # Pretty Assertions |
| |
| [![Latest version](https://img.shields.io/crates/v/pretty-assertions.svg)](https://crates.io/crates/pretty-assertions) |
| [![docs.rs](https://img.shields.io/docsrs/pretty_assertions)](https://docs.rs/pretty_assertions) |
| [![Downloads of latest version](https://img.shields.io/crates/dv/pretty-assertions.svg)](https://crates.io/crates/pretty-assertions) |
| [![All downloads](https://img.shields.io/crates/d/pretty-assertions.svg)](https://crates.io/crates/pretty-assertions) |
| |
| Overwrite `assert_eq!` with a drop-in replacement, adding a colorful diff. |
| |
| ## Usage |
| |
| When writing tests in Rust, you'll probably use `assert_eq!(a, b)` _a lot_. |
| |
| If such a test fails, it will present all the details of `a` and `b`. |
| But you have to spot the differences yourself, which is not always straightforward, |
| like here: |
| |
| ![standard assertion](https://raw.githubusercontent.com/rust-pretty-assertions/rust-pretty-assertions/2d2357ff56d22c51a86b2f1cfe6efcee9f5a8081/examples/standard_assertion.png) |
| |
| Wouldn't that task be _much_ easier with a colorful diff? |
| |
| ![pretty assertion](https://raw.githubusercontent.com/rust-pretty-assertions/rust-pretty-assertions/2d2357ff56d22c51a86b2f1cfe6efcee9f5a8081/examples/pretty_assertion.png) |
| |
| Yep — and you only need **one line of code** to make it happen: |
| |
| ```rust,ignore |
| use pretty_assertions::{assert_eq, assert_ne}; |
| ``` |
| |
| <details> |
| <summary>Show the example behind the screenshots above.</summary> |
| |
| ```rust,ignore |
| // 1. add the `pretty_assertions` dependency to `Cargo.toml`. |
| // 2. insert this line at the top of each module, as needed |
| use pretty_assertions::{assert_eq, assert_ne}; |
| |
| fn main() { |
| #[derive(Debug, PartialEq)] |
| struct Foo { |
| lorem: &'static str, |
| ipsum: u32, |
| dolor: Result<String, String>, |
| } |
| |
| let x = Some(Foo { lorem: "Hello World!", ipsum: 42, dolor: Ok("hey".to_string())}); |
| let y = Some(Foo { lorem: "Hello Wrold!", ipsum: 42, dolor: Ok("hey ho!".to_string())}); |
| |
| assert_eq!(x, y); |
| } |
| ``` |
| |
| </details> |
| |
| ## Semantic Versioning |
| |
| The exact output of assertions is **not guaranteed** to be consistent over time, and may change between minor versions. |
| The output of this crate is designed to be read by a human. It is not suitable for exact comparison, for example in snapshot testing. |
| |
| This crate adheres to semantic versioning for publically exported crate items, **except** the `private` module, which may change between any version. |
| |
| ## Tip |
| |
| Specify it as [`[dev-dependencies]`](http://doc.crates.io/specifying-dependencies.html#development-dependencies) |
| and it will only be used for compiling tests, examples, and benchmarks. |
| This way the compile time of `cargo build` won't be affected! |
| |
| Also add `#[cfg(test)]` to your `use` statements, like this: |
| |
| ```rust,ignore |
| #[cfg(test)] |
| use pretty_assertions::{assert_eq, assert_ne}; |
| ``` |
| |
| ## Notes |
| |
| - Since `Rust 2018` edition, you need to declare |
| `use pretty_assertions::{assert_eq, assert_ne};` per module. |
| Before you would write `#[macro_use] extern crate pretty_assertions;`. |
| - The replacement is only effective in your own crate, not in other libraries |
| you include. |
| - `assert_ne` is also switched to multi-line presentation, but does _not_ show |
| a diff. |
| - Under Windows, the terminal state is modified to properly handle VT100 |
| escape sequences, which may break display for certain use cases. |
| - The minimum supported rust version (MSRV) is 1.35.0 |
| |
| ### `no_std` support |
| |
| For `no_std` support, disable the `std` feature and enable the `alloc` feature: |
| |
| ```toml |
| # Cargo.toml |
| pretty_assertions = { version= "...", default-features = false, features = ["alloc"] } |
| ``` |
| |
| ## License |
| |
| Licensed under either of |
| |
| - Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or <http://www.apache.org/licenses/LICENSE-2.0>) |
| - MIT license ([LICENSE-MIT](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. |
| |
| ## Development |
| |
| - Cut a new release by creating a GitHub release with tag. Crate will be built and uploaded to crates.io by GHA. |