I’m messing around with some Rust code at the moment, so expect a few posts in the near future. In this post I’ve going to jump straight into unit testing in Rust.<\/p>\n
You don’t need to have a dependency on any unit testing frameworks as Rust has a unit testing framework integrated within it. <\/p>\n
Our unit tests can sit along side our existing code using the conditional compilation annotation #[cfg(test)]<\/em>. Let’s create a simple example test, which assumed we have a Stack implementation to test<\/p>\n The following line simply allows us to use code from the parent scope (i.e. allows us to use the Stack code). <\/p>\n Next up with have the #[test]<\/em> annotation which (probably fairly obviously) declares the function initial_state<\/em> to be a test function. <\/p>\n Ofcourse we need some form of assertation code, hence the assert_eq!<\/em> macro.<\/p>\n We can also test whether our code panics by placed the #[should_panic]<\/em> annotation after the #[test]<\/em> annotation. This denotes that the system under test should panic (similar to exceptions in other languages).<\/p>\n Some times we need to ignore a test, in such cases we can use the #[ignore]<\/em> annotation<\/p>\n Obviously we need run our tests, we can use cargo for this, simple run <\/p>\n We can also run tests in parallel using the -test-threads<\/em> option, for example if we want test to be run in parallel on two threads, we use<\/p>\n\r\n#[cfg(test)]\r\nmod tests {\r\n use super::*;\r\n\r\n #[test]\r\n fn initial_state() {\r\n let s: Stack<i32> = Stack::new();\r\n assert_eq!(s.length, 0);\r\n }\r\n}\r\n<\/pre>\n\r\nuse super::*;\r\n<\/pre>\n
\r\ncargo test\r\n<\/pre>\n
\r\ncargo test -- --test-threads=2\r\n<\/pre>\n