Add SignedRoot methods

eth2/types/src/proposal.rs

@@ -3,10 +3,11 @@ use crate::{Hash256, Slot};
 use bls::Signature;
 use rand::RngCore;
 use serde_derive::Serialize;
-use ssz_derive::{Decode, Encode, TreeHash};
+use ssz::TreeHash;
+use ssz_derive::{Decode, Encode, SignedRoot, TreeHash};
 use test_random_derive::TestRandom;
 
-#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TreeHash, TestRandom)]
+#[derive(Debug, PartialEq, Clone, Serialize, Encode, Decode, TreeHash, TestRandom, SignedRoot)]
 pub struct Proposal {
     pub slot: Slot,
     /// Shard number (spec.beacon_chain_shard_number for beacon chain)
@@ -19,7 +20,7 @@ pub struct Proposal {
 mod tests {
     use super::*;
     use crate::test_utils::{SeedableRng, TestRandom, XorShiftRng};
-    use ssz::{ssz_encode, Decodable, TreeHash};
+    use ssz::{ssz_encode, Decodable, SignedRoot, TreeHash};
 
     #[test]
     pub fn test_ssz_round_trip() {
@@ -43,4 +44,32 @@ mod tests {
         // TODO: Add further tests
         // https://github.com/sigp/lighthouse/issues/170
     }
+
+    #[derive(TreeHash)]
+    struct SignedProposal {
+        pub slot: Slot,
+        pub shard: u64,
+        pub block_root: Hash256,
+    }
+
+    impl Into<SignedProposal> for Proposal {
+        fn into(self) -> SignedProposal {
+            SignedProposal {
+                slot: self.slot,
+                shard: self.shard,
+                block_root: self.block_root,
+            }
+        }
+    }
+
+    #[test]
+    pub fn test_signed_root() {
+        let mut rng = XorShiftRng::from_seed([42; 16]);
+        let original = Proposal::random_for_test(&mut rng);
+
+        let other: SignedProposal = original.clone().into();
+
+        assert_eq!(original.signed_root(), other.hash_tree_root());
+    }
+
 }