Test coverage with Tarpaulin

cargo-tarpaulin is a code coverage reporting tool for the Cargo build system, named for a waterproof cloth used to cover cargo on a ship.

Install Tarpaulin

cargo install cargo-tarpaulin

Run Tarpaulin generate HTML report

cargo tarpaulin --out Html

Run Tarpaulin - print minimalistic text report on the screen

cargo tarpaulin --out Stdout

Run Tarpaulin - both output

cargo tarpaulin --out Html --out Stdout

Only run s subset of the tests

For example, I have a project where I have a number of tests files:

src/
├── collect.rs
├── db.rs
├── language.rs
├── main.rs
├── test_collect.rs
├── test_db.rs
├── test_utils.rs
└── test_web.rs

I could get a coverage report of the database tests by running the following:

cargo tarpaulin --out Html  --out Stdout -- test_db

ASLR disable failed: EPERM: Operation not permitted

When running inside a Docker container you might get the above error message.

Using the Llvm engine solved this problem for me.

--engine Llvm

Tarpaulin every format

cargo tarpaulin --out Html --out Stdout --out Json --out xml --out Lcov --out Markdown

.gitignore files generated by Tarpaulin

cobertura.xml
lcov.info
tarpaulin-report.*