Add optional "arbitrary" crate integration

Cargo.toml

@@ -23,6 +23,7 @@ default = ["std"]
 std = []
 
 [dependencies]
+arbitrary = { version = "1.1.6", optional = true }
 serde = { version = "1.0.60", optional = true, default-features = false, features = ["alloc"] }
 
 [dev-dependencies]

src/arbitrary.rs

@@ -0,0 +1,18 @@
+use super::{Bytes, BytesMut};
+use arbitrary::{Arbitrary, Result};
+
+impl<'a> Arbitrary<'a> for Bytes {
+    fn arbitrary(u: &mut arbitrary::Unstructured<'a>) -> Result<Self> {
+        let len = u.arbitrary_len::<u8>()?;
+
+        u.bytes(len).map(Bytes::copy_from_slice)
+    }
+}
+
+impl<'a> Arbitrary<'a> for BytesMut {
+    fn arbitrary(u: &mut arbitrary::Unstructured<'a>) -> Result<Self> {
+        let len = u.arbitrary_len::<u8>()?;
+
+        u.bytes(len).map(|slice| BytesMut::from_vec(slice.to_vec()))
+    }
+}

src/lib.rs

@@ -91,6 +91,9 @@ pub use crate::bytes_mut::BytesMut;
 #[cfg(feature = "serde")]
 mod serde;
 
+#[cfg(feature = "arbitrary")]
+mod arbitrary;
+
 #[inline(never)]
 #[cold]
 fn abort() -> ! {