When you're writing tests it can be useful to know what in your codebase haven't been tested. Checking the code coverage will show you what individual lines haven't been tested and will let you go in and fill the gaps in your test suite.
With Rust you can do this using the LLVM code coverage tools.
There's a lot of info here in the rustc book. For the abridged version install the cargo llvm-cov helper.
cargo install cargo-llvm-cov
Once that installs, run your tests like so:
cargo llvm-cov --open
This will open your browser to an LLVM HTML coverage report showing the tree of files in your codebase. Click through to the files that you're currently testing, and you'll see the lines that are covered and the lines that are not:
Related
Learning Rust through the Advent of Code
An introduction to the Rust programming language through an Advent of Code 2018 challenge.
Safe, efficient and fast native Node extensions with Rust
Everyone seems to be rewriting all their JavaScript in Rust. I look at how you can use Rust, Rayon a…
Projects
A list of projects that I've worked on over the years.
Don't use boxed trait objects
Boxed trait objects are a great scape goat for solving hard borrow checker errors. But when writing…
Dump Rust Struct or Enum Memory Representation as Bytes
How to get the in-memory representation of Rust Structs or Enums using unsafe and raw pointers. It c…