Add state helpers from #148

beacon_node/beacon_chain/src/info.rs

@@ -1,5 +1,11 @@
 use super::{BeaconChain, ClientDB, SlotClock};
-use types::PublicKey;
+use types::{beacon_state::Error as BeaconStateError, PublicKey};
+
+#[derive(Debug, PartialEq)]
+pub enum Error {
+    SlotClockError,
+    BeaconStateError(BeaconStateError),
+}
 
 impl<T, U> BeaconChain<T, U>
 where
@@ -39,10 +45,14 @@ where
         }
     }
 
-    pub fn block_proposer(&self, slot: u64) -> Option<usize> {
-        let present_slot = self.present_slot()?;
-        let state = self.state(present_slot).ok()?;
-        state.get_beacon_proposer_index(slot, &self.spec)
+    pub fn block_proposer(&self, slot: u64) -> Result<usize, Error> {
+        // TODO: fix unwrap
+        let present_slot = self.present_slot().unwrap();
+        // TODO: fix unwrap
+        let state = self.state(present_slot).unwrap();
+        let index = state.get_beacon_proposer_index(slot, &self.spec)?;
+
+        Ok(index)
     }
 
     pub fn justified_slot(&self) -> u64 {
@@ -60,3 +70,9 @@ where
         Some(state.attestation_slot_and_shard_for_validator(validator_index, &self.spec))
     }
 }
+
+impl From<BeaconStateError> for Error {
+    fn from(e: BeaconStateError) -> Error {
+        Error::BeaconStateError(e)
+    }
+}

beacon_node/beacon_chain/src/state_transition.rs

@@ -98,7 +98,7 @@ where
 
         let block_proposer_index = state
             .get_beacon_proposer_index(block.slot, &self.spec)
-            .ok_or(Error::NoBlockProducer)?;
+            .map_err(|_| Error::NoBlockProducer)?;
         let block_proposer = &state.validator_registry[block_proposer_index];
 
         if verify_block_signature {
@@ -294,7 +294,7 @@ where
         );
 
         if state.slot % self.spec.epoch_length == 0 {
-            state.per_epoch_processing(&self.spec);
+            state.per_epoch_processing(&self.spec).unwrap();
         }
 
         Ok(state)