2.2 KiB
Code Coverage
In computer science, test coverage is a measure used to describe the degree to which the source code of a program is executed when a particular test suite runs. A program with high test coverage, measured as a percentage, has had more of its source code executed during testing, which suggests it has a lower chance of containing undetected software bugs compared to a program with low test coverage. (Wikipedia)
Automated reports
For pull requests and master pushes we generate code coverage reports on CI and upload them to codecov:
Generating Kotlin reports locally
Locally you can generate a coverage report with the following command:
./gradlew -Pcoverage :glean-core:build
After that you'll find an HTML report at the following location:
glean-core/android/build/reports/jacoco/jacocoTestReport/jacocoTestReport/html/index.html
Generating Rust reports locally
Generating the Rust coverage report requires a significant amount of RAM during the build.
We use grcov to collect and aggregate code coverage information. Releases can be found on the grcov Release page.
The build process requires a Rust Nightly version. Install it using rustup:
rustup toolchain add nightly
To generate an HTML report, genhtml from the lcov package is required. Install it through your system's package manager.
After installation you can build the Rust code and generate a report:
export CARGO_INCREMENTAL=0
export RUSTFLAGS='-Zprofile -Ccodegen-units=1 -Cinline-threshold=0 -Clink-dead-code -Coverflow-checks=off -Zno-landing-pads'
cargo +nightly test
zip -0 ccov.zip `find . \( -name "glean*.gc*" \) -print`
grcov ccov.zip -s . -t lcov --llvm --branch --ignore-not-existing --ignore-dir "/*" -o lcov.info
genhtml -o report/ --show-details --highlight --ignore-errors source --legend lcov.info
After that you'll find an HTML report at the following location:
report/index.html