Add arbitrary trait implementation

ethbloom/Cargo.toml

@@ -26,6 +26,7 @@ default = ["std", "serialize", "rustc-hex"]
 std = ["fixed-hash/std", "crunchy/std"]
 serialize = ["std", "impl-serde"]
 rustc-hex = ["fixed-hash/rustc-hex"]
+arbitrary = ["fixed-hash/arbitrary"]
 
 [[bench]]
 name = "bloom"

ethereum-types/Cargo.toml

@@ -22,3 +22,4 @@ serde_json = "1.0.41"
 default = ["std", "serialize"]
 std = ["uint-crate/std", "fixed-hash/std", "ethbloom/std", "primitive-types/std"]
 serialize = ["std", "impl-serde", "primitive-types/serde", "ethbloom/serialize"]
+arbitrary = ["ethbloom/arbitrary", "fixed-hash/arbitrary", "uint-crate/arbitrary"]

fixed-hash/Cargo.toml

@@ -19,6 +19,7 @@ quickcheck = { version = "0.9.0", optional = true }
 rand = { version = "0.7.2", optional = true, default-features = false }
 rustc-hex = { version = "2.0.1", optional = true, default-features = false }
 static_assertions = "1.0.0"
+arbitrary = { version = "0.4", optional = true }
 
 [dev-dependencies]
 rand_xorshift = "0.2.0"

fixed-hash/README.md

@@ -64,3 +64,5 @@ fixed-hash = { version = "0.3", default-features = false }
     - Disabled by default.
 - `api-dummy`: Generate a dummy hash type for API documentation.
     - Enabled by default at `docs.rs`
+- `arbitrary`: Allow for creation of a hash from random unstructured input.
+    - Disabled by default.

fixed-hash/src/hash.rs

@@ -316,6 +316,7 @@ macro_rules! construct_fixed_hash {
 		impl_cmp_for_fixed_hash!($name);
 		impl_rustc_hex_for_fixed_hash!($name);
 		impl_quickcheck_for_fixed_hash!($name);
+		impl_arbitrary_for_fixed_hash!($name);
 	}
 }
 
@@ -636,6 +637,42 @@ macro_rules! impl_quickcheck_for_fixed_hash {
 	};
 }
 
+// When the `arbitrary` feature is disabled.
+//
+// # Note
+//
+// Feature guarded macro definitions instead of feature guarded impl blocks
+// to work around the problems of introducing `arbitrary` crate feature in
+// a user crate.
+#[cfg(not(feature = "arbitrary"))]
+#[macro_export]
+#[doc(hidden)]
+macro_rules! impl_arbitrary_for_fixed_hash {
+	( $name:ident ) => {};
+}
+
+// When the `arbitrary` feature is enabled.
+//
+// # Note
+//
+// Feature guarded macro definitions instead of feature guarded impl blocks
+// to work around the problems of introducing `arbitrary` crate feature in
+// a user crate.
+#[cfg(feature = "arbitrary")]
+#[macro_export]
+#[doc(hidden)]
+macro_rules! impl_arbitrary_for_fixed_hash {
+	( $name:ident ) => {
+		impl $crate::arbitrary::Arbitrary for $name {
+			fn arbitrary(u: &mut $crate::arbitrary::Unstructured<'_>) -> $crate::arbitrary::Result<Self> {
+				let mut res = Self::zero();
+				u.fill_buffer(&mut res.0)?;
+				Ok(Self::from(res))
+			}
+		}
+	};
+}
+
 #[macro_export]
 #[doc(hidden)]
 macro_rules! impl_ops_for_hash {

fixed-hash/src/lib.rs

@@ -46,6 +46,10 @@ pub use rand;
 #[doc(hidden)]
 pub use quickcheck;
 
+#[cfg(feature = "arbitrary")]
+#[doc(hidden)]
+pub use arbitrary;
+
 #[macro_use]
 mod hash;
 

primitive-types/Cargo.toml

@@ -22,3 +22,4 @@ rustc-hex = ["fixed-hash/rustc-hex"]
 serde = ["std", "impl-serde"]
 codec = ["impl-codec"]
 rlp = ["impl-rlp"]
+arbitrary = ["fixed-hash/arbitrary", "uint/arbitrary"]

uint/Cargo.toml

@@ -16,6 +16,7 @@ qc = { package = "quickcheck", version = "0.9.0", optional = true }
 rand = { version = "0.7.2", default-features = false, optional = true }
 rustc-hex = { version = "2.0.1", default-features = false }
 static_assertions = "1.0.0"
+arbitrary = { version = "0.4", optional = true }
 
 [features]
 default = ["std"]

uint/README.md

@@ -69,3 +69,5 @@ see fuzz [README.md](fuzz/README.md)
 	- Enabled by default.
 - `quickcheck`: Enable quickcheck-style property testing
 	- Use with `cargo test --release --features=quickcheck`.
+- `arbitrary`: Allow for creation of an `uint` object from random unstructured input for use with fuzzers that use the `arbitrary` crate.
+	- Disabled by default.

uint/src/lib.rs

@@ -29,6 +29,10 @@ pub use qc;
 #[doc(hidden)]
 pub use rand;
 
+#[cfg(feature = "arbitrary")]
+#[doc(hidden)]
+pub use arbitrary;
+
 #[doc(hidden)]
 pub use static_assertions;
 

uint/src/uint.rs

@@ -1554,6 +1554,7 @@ macro_rules! construct_uint {
 		// `$n_words * 8` because macro expects bytes and
 		// uints use 64 bit (8 byte) words
 		$crate::impl_quickcheck_arbitrary_for_uint!($name, ($n_words * 8));
+		$crate::impl_arbitrary_for_uint!($name, ($n_words * 8));
 	}
 }
 
@@ -1632,3 +1633,26 @@ macro_rules! impl_quickcheck_arbitrary_for_uint {
 macro_rules! impl_quickcheck_arbitrary_for_uint {
 	($uint: ty, $n_bytes: tt) => {};
 }
+
+
+#[cfg(feature = "arbitrary")]
+#[macro_export]
+#[doc(hidden)]
+macro_rules! impl_arbitrary_for_uint {
+	($uint: ty, $n_bytes: tt) => {
+		impl $crate::arbitrary::Arbitrary for $uint {
+			fn arbitrary(u: &mut $crate::arbitrary::Unstructured<'_>) -> $crate::arbitrary::Result<Self> {
+				let mut res = [0u8; $n_bytes];
+				u.fill_buffer(&mut res)?;
+				Ok(Self::from(res))
+			}
+		}
+	};
+}
+
+#[cfg(not(feature = "arbitrary"))]
+#[macro_export]
+#[doc(hidden)]
+macro_rules! impl_arbitrary_for_uint {
+	($uint: ty, $n_bytes: tt) => {};
+}