Merge rust-bitcoin#3257: Add Arbitrary to Weight

f8edbd1 Add Arbitrary to Weight (yancy)

Pull request description:

  Adds Arbitrary to the Weight type.  I had meant to add this with the initial Arbitrary PR but I overlooked it.

ACKs for top commit:
  tcharding:
    ACK f8edbd1
  Kixunil:
    ACK f8edbd1

Tree-SHA512: b886f78285b5cd06b2531a1e53272cad623a8e43e76e8108abe90668b45d00674b6a867c5ff980ee7f0a34919e1d6bb534624bd0bc67a53c8c9a41ea2ed504e8

units/src/weight.rs

@@ -8,6 +8,9 @@ use core::ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Sub, SubAssign};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
+#[cfg(feature = "arbitrary")]
+use arbitrary::{Arbitrary, Unstructured};
+
 /// The factor that non-witness serialization data is multiplied by during weight calculation.
 pub const WITNESS_SCALE_FACTOR: usize = 4;
 
@@ -204,6 +207,14 @@ impl<'a> core::iter::Sum<&'a Weight> for Weight {
 
 crate::impl_parse_str_from_int_infallible!(Weight, u64, from_wu);
 
+#[cfg(feature = "arbitrary")]
+impl<'a> Arbitrary<'a> for Weight {
+    fn arbitrary(u: &mut Unstructured<'a>) -> arbitrary::Result<Self> {
+        let w = u64::arbitrary(u)?;
+        Ok(Weight(w))
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;