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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
commit | 0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d (patch) | |
tree | a31f07c9bcca9d56ce61e9a1ffd30ef350d513aa /third_party/rust/arbitrary/README.md | |
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Adding upstream version 115.8.0esr.upstream/115.8.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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diff --git a/third_party/rust/arbitrary/README.md b/third_party/rust/arbitrary/README.md new file mode 100644 index 0000000000..3f5619b687 --- /dev/null +++ b/third_party/rust/arbitrary/README.md @@ -0,0 +1,129 @@ +<div align="center"> + + <h1><code>Arbitrary</code></h1> + + <p><strong>The trait for generating structured data from arbitrary, unstructured input.</strong></p> + + <img alt="GitHub Actions Status" src="https://github.com/rust-fuzz/rust_arbitrary/workflows/Rust/badge.svg"/> + +</div> + +## About + +The `Arbitrary` crate lets you construct arbitrary instances of a type. + +This crate is primarily intended to be combined with a fuzzer like [libFuzzer +and `cargo-fuzz`](https://github.com/rust-fuzz/cargo-fuzz) or +[AFL](https://github.com/rust-fuzz/afl.rs), and to help you turn the raw, +untyped byte buffers that they produce into well-typed, valid, structured +values. This allows you to combine structure-aware test case generation with +coverage-guided, mutation-based fuzzers. + +## Documentation + +[**Read the API documentation on `docs.rs`!**](https://docs.rs/arbitrary) + +## Example + +Say you're writing a color conversion library, and you have an `Rgb` struct to +represent RGB colors. You might want to implement `Arbitrary` for `Rgb` so that +you could take arbitrary `Rgb` instances in a test function that asserts some +property (for example, asserting that RGB converted to HSL and converted back to +RGB always ends up exactly where we started). + +### Automatically Deriving `Arbitrary` + +Automatically deriving the `Arbitrary` trait is the recommended way to implement +`Arbitrary` for your types. + +Automatically deriving `Arbitrary` requires you to enable the `"derive"` cargo +feature: + +```toml +# Cargo.toml + +[dependencies] +arbitrary = { version = "1", features = ["derive"] } +``` + +And then you can simply add `#[derive(Arbitrary)]` annotations to your types: + +```rust +// rgb.rs + +use arbitrary::Arbitrary; + +#[derive(Arbitrary)] +pub struct Rgb { + pub r: u8, + pub g: u8, + pub b: u8, +} +``` + +#### Customizing single fields + +This can be particular handy if your structure uses a type that does not implement `Arbitrary` or you want to have more customization for particular fields. + +```rust +#[derive(Arbitrary)] +pub struct Rgba { + // set `r` to Default::default() + #[arbitrary(default)] + pub r: u8, + + // set `g` to 255 + #[arbitrary(value = 255)] + pub g: u8, + + // Generate `b` with a custom function of type + // + // fn(&mut Unstructured) -> arbitrary::Result<T> + // + // where `T` is the field's type. + #[arbitrary(with = arbitrary_b)] + pub b: u8, + + // Generate `a` with a custom closure (shortuct to avoid a custom funciton) + #[arbitrary(with = |u: &mut Unstructured| u.int_in_range(0..=64))] + pub a: u8, +} + +fn arbitrary_b(u: &mut Unstructured) -> arbitrary::Result<u8> { + u.int_in_range(64..=128) +} +``` + +### Implementing `Arbitrary` By Hand + +Alternatively, you can write an `Arbitrary` implementation by hand: + +```rust +// rgb.rs + +use arbitrary::{Arbitrary, Result, Unstructured}; + +#[derive(Copy, Clone, Debug)] +pub struct Rgb { + pub r: u8, + pub g: u8, + pub b: u8, +} + +impl<'a> Arbitrary<'a> for Rgb { + fn arbitrary(u: &mut Unstructured<'a>) -> Result<Self> { + let r = u8::arbitrary(u)?; + let g = u8::arbitrary(u)?; + let b = u8::arbitrary(u)?; + Ok(Rgb { r, g, b }) + } +} +``` + +## License + +Licensed under dual MIT or Apache-2.0 at your choice. + +Unless you explicitly state otherwise, any contribution intentionally submitted +for inclusion in this project by you, as defined in the Apache-2.0 license, +shall be dual licensed as above, without any additional terms or conditions. |