2.7. Testing a Rust project

Test your Rust program by using the Cargo build tool. Cargo first rebuilds your project and then runs the tests found in the project. Test functions must be free, monomorphic, and take no arguments. The function return type must be either () or Result<(), E> where E: Error.

By default, Rust projects are tested in debug mode. For information on testing your project in release mode, see Testing a Rust project in release mode.