Add BeaconBlock genesis

beacon_chain/genesis/Cargo.toml

@@ -2,6 +2,7 @@
 name = "genesis"
 version = "0.1.0"
 authors = ["Paul Hauner <paul@paulhauner.com>"]
+edition = "2018"
 
 [dependencies]
 bls = { path = "../utils/bls"  }

beacon_chain/genesis/src/beacon_block.rs

@@ -0,0 +1,38 @@
+use bls::Signature;
+use spec::ChainSpec;
+use types::{BeaconBlock, BeaconBlockBody};
+
+/// Generate a genesis BeaconBlock.
+pub fn genesis_beacon_block(spec: &ChainSpec) -> BeaconBlock {
+    BeaconBlock {
+        slot: spec.initial_slot_number,
+        parent_root: spec.zero_hash,
+        state_root: spec.zero_hash,
+        randao_reveal: spec.zero_hash,
+        candidate_pow_receipt_root: spec.zero_hash,
+        signature: Signature::default(),
+        body: BeaconBlockBody {
+            proposer_slashings: vec![],
+            casper_slashings: vec![],
+            attestations: vec![],
+            deposits: vec![],
+            exits: vec![],
+        },
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    // TODO: enhance these tests.
+    // https://github.com/sigp/lighthouse/issues/117
+
+    #[test]
+    fn test_genesis() {
+        let spec = ChainSpec::foundation();
+
+        // This only checks that the function runs without panic.
+        genesis_beacon_block(&spec);
+    }
+}

beacon_chain/genesis/src/lib.rs

@@ -4,6 +4,7 @@ extern crate validator_induction;
 extern crate validator_shuffling;
 
 mod beacon_state;
+mod beacon_block;
 
-pub use beacon_state::{genesis_beacon_state, Error as GenesisError};
-
+pub use crate::beacon_block::genesis_beacon_block;
+pub use crate::beacon_state::{genesis_beacon_state, Error as GenesisError};

beacon_chain/types/src/beacon_block.rs

@@ -1,7 +1,7 @@
 use super::ssz::{Decodable, DecodeError, Encodable, SszStream};
 use super::{BeaconBlockBody, Hash256};
 use crate::test_utils::TestRandom;
-use bls::AggregateSignature;
+use bls::Signature;
 use rand::RngCore;
 
 #[derive(Debug, PartialEq, Clone, Default)]
@@ -11,7 +11,7 @@ pub struct BeaconBlock {
     pub state_root: Hash256,
     pub randao_reveal: Hash256,
     pub candidate_pow_receipt_root: Hash256,
-    pub signature: AggregateSignature,
+    pub signature: Signature,
     pub body: BeaconBlockBody,
 }