treewide/test: Use `impl Arbitrary for Oid`

Many usages of `Oid::from_sha1` are actually in the context of
generating arbitrary `Oid`s. In these cases, `impl Arbitrary for Oid`
may be used directly.

crates/radicle-core/src/repo.rs

@@ -313,10 +313,7 @@ pub mod arbitrary {
 #[cfg(feature = "qcheck")]
 impl qcheck::Arbitrary for RepoId {
     fn arbitrary(g: &mut qcheck::Gen) -> Self {
-        let bytes = <[u8; 20]>::arbitrary(g);
-        let oid = radicle_oid::Oid::from_sha1(bytes);
-
-        RepoId::from(oid)
+        RepoId::from(radicle_oid::Oid::arbitrary(g))
     }
 }
 

crates/radicle-protocol/src/wire.rs

@@ -624,8 +624,8 @@ mod tests {
     }
 
     #[quickcheck]
-    fn prop_oid(input: [u8; git::Oid::SHA1_LEN]) {
-        roundtrip(git::Oid::from_sha1(input));
+    fn prop_oid(input: git::Oid) {
+        roundtrip(input);
     }
 
     #[test]

crates/radicle/src/storage/refs/arbitrary.rs

@@ -17,7 +17,7 @@ where
 
     if bool::arbitrary(g) {
         level = Some(FeatureLevel::Parent);
-        let parent = Oid::from_sha1(Arbitrary::arbitrary(g));
+        let parent = Oid::arbitrary(g);
         refs.insert(SIGREFS_PARENT.to_ref_string(), parent);
     }
 
@@ -28,13 +28,12 @@ where
         id: *signer.node_id(),
         level: level.unwrap_or_else(|| FeatureLevel::arbitrary(g)),
         parent: Arbitrary::arbitrary(g),
-        at: Oid::from_sha1(Arbitrary::arbitrary(g)),
+        at: Oid::arbitrary(g),
     }
 }
 
 impl Arbitrary for Refs {
     fn arbitrary(g: &mut qcheck::Gen) -> Self {
-        let mut bytes: [u8; 20] = [0; 20];
         let names = &[
             "heads/master",
             "heads/feature/1",
@@ -49,10 +48,7 @@ impl Arbitrary for Refs {
         let mut refs = Self::new();
         for _ in 0..g.size().min(names.len()) {
             if let Some(name) = g.choose(names) {
-                for byte in &mut bytes {
-                    *byte = u8::arbitrary(g);
-                }
-                let oid = storage::Oid::from_sha1(bytes);
+                let oid = storage::Oid::arbitrary(g);
                 let name = git::fmt::RefString::try_from(*name).unwrap();
 
                 refs.insert(name, oid);
@@ -66,7 +62,7 @@ impl Arbitrary for RefsAt {
     fn arbitrary(g: &mut qcheck::Gen) -> Self {
         Self {
             remote: PublicKey::arbitrary(g),
-            at: Oid::from_sha1(Arbitrary::arbitrary(g)),
+            at: Oid::arbitrary(g),
         }
     }
 }

crates/radicle/src/test/arbitrary.rs

@@ -25,8 +25,7 @@ use crate::test::storage::{MockRepository, MockStorage};
 use crate::{cob, git};
 
 pub fn oid() -> storage::Oid {
-    let oid_bytes: [u8; 20] = r#gen(1);
-    storage::Oid::from_sha1(oid_bytes)
+    r#gen(1)
 }
 
 pub fn entry_id() -> cob::EntryId {