The current code coverage for the main branch is automatically published on every push to main on https://rust-pcap.github.io/pcap/.
To obtain code coverage locally you will need the nightly compiler toolchain, compatible LLVM coverage tools, and grcov.
Make sure you have the nightly toolchain installed with rustup:
rustup install nightly
The easiest way to obtain compatible LLVM coverage tools is by adding the llvm-tools-preview rustup component (for nightly!):
rustup +nightly component add llvm-tools-preview
grcov can be installed through cargo:
cargo install grcov
First, switch to the nightly toolchain. Note that switching toolchains is necessary, as opposed to just using the +nightly option, because grcov does not have such an option and will not be able to find (or worse, will find the incorrect version of) llvm-tools-preview.
rustup default nightly
Clean any previously compiled objects and binaries.
cargo clean
Compile and run the tests. We set RUSTFLAGS="-C instrument-coverage" to enable source-based code coverage and LLVM_PROFILE_FILE="target/debug/coverage/profraw/pcap-%p-%m.profraw" to make sure each test gets its own profile information.
RUSTFLAGS="-C instrument-coverage" LLVM_PROFILE_FILE="target/debug/profraw/pcap-%p-%m.profraw" cargo test --all-features
And finally, run grcov to obtain a report.
grcov target/debug/profraw -s src/ --binary-path ./target/debug/ -t html --branch --ignore-not-existing -o ./target/debug/coverage/
The code coverage report will be available in target/debug/coverage/index.html which you can explore in your browser.
xdg-open target/debug/coverage/index.html
For more information on LLVM code coverage in Rust: https://doc.rust-lang.org/rustc/instrument-coverage.html
For more information on grcov: https://github.com/mozilla/grcov