Merge rust-bitcoin#4689: Add Arbitrary impl for relative::LockTime

d1f3976 Add Arbitrary impl for relative::LockTime (Shing Him Ng)

Pull request description:

  Closes rust-bitcoin#4685


ACKs for top commit:
  tcharding:
    ACK d1f3976
  apoelstra:
    ACK d1f3976; successfully ran local tests


Tree-SHA512: 2560726cbc9c4013a5ebf23b1447c5fb78195a4915d1bd01c608c677a90a63d261bace15a3b60172aa4d66f23ed288e8c0ef92497a2e1277d4568ada113e9039

Author: apoelstra

primitives/src/locktime/relative.rs

@@ -7,6 +7,9 @@
 
 use core::{convert, fmt};
 
+#[cfg(feature = "arbitrary")]
+use arbitrary::{Arbitrary, Unstructured};
+
 use internals::write_err;
 
 use crate::Sequence;
@@ -517,6 +520,16 @@ impl std::error::Error for IsSatisfiedByTimeError {
     }
 }
 
+#[cfg(feature = "arbitrary")]
+impl<'a> Arbitrary<'a> for LockTime {
+    fn arbitrary(u: &mut Unstructured<'a>) -> arbitrary::Result<Self> {
+        match bool::arbitrary(u)? {
+            true => Ok(LockTime::Blocks(NumberOfBlocks::arbitrary(u)?)),
+            false => Ok(LockTime::Time(NumberOf512Seconds::arbitrary(u)?))
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use units::{BlockHeight, BlockTime};