ctest

Documentation

Automated testing of FFI bindings in Rust. This repository is intended to validate the *-sys crates that can be found on crates.io to ensure that the APIs in Rust match the APIs defined in C.

MSRV (Minimum Supported Rust Version)

The MSRV is 1.88.0 because of the transitive dependencies. Note that MSRV may be changed anytime by dependencies.

Example

Unfortunately the usage today is a little wonky, but to use this library, first, create a new Cargo project in your repo:

$ cargo new --bin systest

Then, edit systest/Cargo.toml to add these dependencies:

[package]
# ...
build = "build.rs"

[dependencies]
mylib-sys = { path = "../mylib-sys" }
libc = "0.2"

[build-dependencies]
ctest = "0.5.0-beta.0"

Next, add a build script to systest/build.rs:

fn main() {
    let mut cfg = ctest::TestGenerator::new();

    // Include the header files where the C APIs are defined
    cfg.header("foo.h")
       .header("bar.h");

    // Include the directory where the header files are defined
    cfg.include("path/to/include");

    // Generate the tests, passing the path to the `*-sys` library as well as
    // the module to generate.
    ctest::generate_test(&mut cfg, "../mylib-sys/lib.rs", "all.rs");
}

Next, add this to src/main.rs

#![allow(bad_style)]

use libc::*;
use mylib_sys::*;

include!(concat!(env!("OUT_DIR"), "/all.rs"));

And you're good to go! To run the tests execute cargo run in the systest directory, and everything should be kicked into action!

How it works

This library will parse the *-sys crate to learn about all definitions within. It will then generate a test suite to ensure that all function signatures, constant values, struct layout/alignment, type size/alignment, etc, all match their C equivalent.

The generated tests come in two forms. One is a Rust file which contains the main function (hence the include! above), and another is a C file which is compiled as part of the build script. The C file is what includes all headers and returns information about the C side of things (which is validated in Rust).

A large amount of configuration can be applied to how the C file is generated, you can browse the documentation.

Projects using ctest

License

This project is licensed under either of

Apache License, Version 2.0, (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)

at your option.

Modifying test templates

If you modify the test templates for either Rust or C in any way, then before contributing you must run the following command to update the pre-generated test files we check against:

$ LIBC_BLESS=1 cargo test

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in ctest by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

ctest 0.5.0-beta.2