testing.rst

Testing

Like in any other Rust project it is possible to write and run unit tests and documentation tests in the kernel.

Running Unit Tests

Unit tests in the kernel are identical to user-space Rust tests:

#[cfg(test)]
mod tests {
    #[test]
    fn it_works() {
        let result = 2 + 2;
        assert_eq!(result, 4);
    }
}

And can be run using the rusttest Make target:

$ make LLVM=1 rusttest

Running Documentation Tests

Like in user-space, it is possible to write documentation tests:

/// ```
/// let result = 2 + 2;
/// assert_eq!(result, 4);
/// ```

Documentation tests use KUnit and it is possible to run them either on boot or using the kunit.py tool:

$ ./tools/testing/kunit/kunit.py run --kunitconfig=rust \
  --make_options LLVM=1 --arch=x86_64

For general information about KUnit and kunit.py`, please refer to Documentation/dev-tools/kunit/start.rst.