Tarpaulin is designed to be a code coverage reporting tool for the Cargo build system, named for a waterproof cloth used to cover cargo on a ship. Currently, tarpaulin provides working line coverage but is still in the early development stage and therefore may contain some bugs. A lot of work has been done to get it working on some example projects and smaller crates so please report anything you find that's wrong. Also, check out our roadmap for planned features.
Tarpaulin only supports x86_64 processors running linux. This is because instrumenting breakpoints into executables and tracing their execution requires processor and OS specific code. It is a goal when greater stability is reached to add wider system support, however this is sufficient to run Tarpaulin on popular CI tools like Travis.
Below is a list of features currently implemented. As Tarpaulin loads binary files into memory and parses the debugging information, different setups could lead to coverage not working. In this instance, please raise an issue detailing your setup and an example project and I'll attempt to fix it (please link us to a repo and the commit containing your project and paste the verbose output).
Tarpaulin depends on cargo which depends on SSL. Make sure you've installed your distros ssl development libraries and they are on your path before attempting to install tarpaulin. For example for Debian/Ubuntu:
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apt-get update && apt-get install libssl-dev
Tarpaulin is a command-line program, you install it into your linux development environment with cargo install:
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cargo install cargo-tarpaulin
To get detailed help on available arguments when running tarpaulin call:
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cargo tarpaulin --help
Currently no options are required, if no root directory is defined Tarpaulin
will run in the current working directory.
Below is a Tarpaulin run utilising one of our example projects. This is a relatively simple project to test and if you check the test, you can see the output correctly reports the lines the test hits.
```text cargo tarpaulin -v Running Tarpaulin Finished dev [unoptimized + debuginfo] target(s) in 0.0 secs Processing simple_project Launching test
running 1 test test tests::bad_test ... ok
test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured
Coverage Results src/unused.rs:4 - hits: 0 src/unused.rs:5 - hits: 0 src/unused.rs:6 - hits: 0 src/unused.rs:7 - hits: 0 src/lib.rs:4 - hits: 1 src/lib.rs:5 - hits: 1 src/lib.rs:6 - hits: 0 src/lib.rs:8 - hits: 1 src/lib.rs:10 - hits: 1 src/lib.rs:21 - hits: 1 src/lib.rs:22 - hits: 1 src/lib.rs:23 - hits: 1
src/lib.rs: 7/8 src/unused.rs: 0/4
58.33% coverage, 7/12 lines covered Tarpaulin finished ```
Hint: if using coveralls.io with travis-ci run with the options "--ciserver travis-ci --coveralls $TRAVISJOBID". The coveralls.io repo-token is mainly designed for private repos and it won't generate a badge for the coverage results submitted (although you can still see them on the coveralls web interface). For an example of a project using Tarpaulin, you can check out my crate keygraph-rs.
The expected most common usecase is launching coverage via a CI service to upload to a site like codecov or coveralls. Given the built in support and ubiquity of travis-ci it seems prudent to document the required steps here for new users. To follow these steps you'll first need a travis-ci and a project setup for your coverage reporting site of choice.
We recommend taking the minimal rust .travis.yml, installing the libssl-dev dependency tarpaulin has and then running Tarpaulin with the version of rustc you require.
The travis-install shell script will install the latest tagged release built
on travis to your travis instance and significantly speeds up the travis
builds. If you want an earlier version of tarpaulin, look at the script to
see what you need to implement and adjust accordingly or use
cargo install cargo-tarpaulin and specify the version in the arguments.
For codecov.io you'll need to export CODECOV_TOKEN are instructions on this in the settings of your codecov project.
```yml language: rust dist: trusty addons: apt: packages: - libssl-dev cache: cargo rust: - stable - beta - nightly matrix: allow_failures: - rust: nightly script: - cargo clean - cargo build - cargo test
aftersuccess: | if [[ "$TRAVISRUSTVERSION" == stable ]]; then bash <(curl https://raw.githubusercontent.com/xd009642/tarpaulin/master/travis-install.sh) # Uncomment the following line for coveralls.io # cargo tarpaulin --ciserver travis-ci --coveralls $TRAVISJOB_ID
# Uncomment the following two lines create and upload a report for codecov.io
# cargo tarpaulin --out Xml
# bash <(curl -s https://codecov.io/bash)
fi ```
Issues, feature requests and pull requests are always welcome! For a guide on how to approach bugs found in Tarpaulin and adding features please check CONTRIBUTING.md.
Tarpaulin is currently licensed under the terms of both the MIT license and the Apache License (Version 2.0). See LICENSE-MIT and LICENSE-APACHE for more details.
I wouldn't have been able to make progress as quickly in this project without Joseph Kain's blog on writing a debugger in Rust and C. It's a great read, so I recommend you check it out here.