# ctest
[](https://travis-ci.org/alexcrichton/ctest)
[](https://ci.appveyor.com/project/alexcrichton/ctest)
[Documentation][dox]
[dox]: https://docs.rs/ctest
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.
### 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:
```toml
[package]
# ...
build = "build.rs"
[dependencies]
my-sys-library = { path = "../my-sys-library" }
libc = "0.2"
[build-dependencies]
ctest = "0.1"
```
Next, add a build script to `systest/build.rs`:
```rust
extern crate ctest;
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.
cfg.generate("../my-sys-library/lib.rs", "all.rs");
}
```
Next, add this to `src/main.rs`
```rust
#![allow(bad_style)]
extern crate my_sys_library;
extern crate libc;
use libc::*;
use my_sys_library::*;
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 extern fn
definitions within. It will then generate a test suite to ensure that all
function 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][dox].
### Projects using ctest
* [libc](https://github.com/rust-lang/libc)
* [git2-rs](https://github.com/alexcrichton/git2-rs)
* [ssh2-rs](https://github.com/alexcrichton/ssh2-rs)
* [libz-sys](https://github.com/alexcrichton/libz-sys)
* [openssl-sys](https://github.com/sfackler/rust-openssl)
### License
`ctest` is primarily distributed under the terms of both the MIT license and
the Apache License (Version 2.0), with portions covered by various BSD-like
licenses.
See LICENSE-APACHE, and LICENSE-MIT for details.