Some people despise developing with unit tests, but I prefer to use them and leverage them to the allow me to quickly push new code and be more confident that it works! I love doing TDD (test-driven development) which inherently involves continuously re-running the tests, and regardless of what language you are coding in, being able to run your tests in "watch mode" makes TDD faster and easier than without it!
TDD For Rust Development
Cargo is basically THE command-line tool for day-to-day Rust development. It takes care of being the package manager for Rust libraries, compiling the Rust code down to binary, and running the tests. The default command to run tests with cargo is just "test".
cargo test
I was actually rather confused that a simple -w or --watch on the end just gave me errors that they were unrecognized flags. Shoutout to my friends on Reddit for responding to me question on this, and it turns out in Cargo land there is a completely different tool, cargo-watch.
But it's rather easy to install:
cargo install cargo-watch
Yay! Now you should be able to use it! This library actually integrates into cargo, and our first command is still cargo, but then we call watch, followed by the "-x" and the command we want it to rerun, which in this case is just test.
Phew, so when we put it all together it looks like this:
cargo watch -x test
Interestingly, it seems that it also works when I use cargo-watch directly:
cargo-watch -x test
If you are curious about this mystery like me, feel free to check out and comment on this Github issue about this very thing.
Try It Out On Exercism
Downloading, solving, and submitting the exercises on Exercism.io is a great way to get started with a simple Rust project that already has unit tests setup for you. You can even set up the Exercism projects in your own Github repo as described in this blog post here.
Happy Coding!
If you have any questions or just want to say hi feel free to hit me up on Twitter @JimLynchCodes, YouTube @JimLynchCodes, or in the comments below!
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