Implement very raw state transition logic

beacon_node/beacon_chain/tests/chain.rs

@@ -0,0 +1,50 @@
+use beacon_chain::{BeaconChain, BlockProcessingOutcome};
+use bls::Signature;
+use db::{
+    stores::{BeaconBlockStore, BeaconStateStore},
+    MemoryDB,
+};
+use slot_clock::TestingSlotClock;
+use spec::ChainSpec;
+use std::sync::Arc;
+
+fn in_memory_test_stores() -> (
+    Arc<MemoryDB>,
+    Arc<BeaconBlockStore<MemoryDB>>,
+    Arc<BeaconStateStore<MemoryDB>>,
+) {
+    let db = Arc::new(MemoryDB::open());
+    let block_store = Arc::new(BeaconBlockStore::new(db.clone()));
+    let state_store = Arc::new(BeaconStateStore::new(db.clone()));
+    (db, block_store, state_store)
+}
+
+fn in_memory_test_chain(
+    spec: ChainSpec,
+) -> (Arc<MemoryDB>, BeaconChain<MemoryDB, TestingSlotClock>) {
+    let (db, block_store, state_store) = in_memory_test_stores();
+    let slot_clock = TestingSlotClock::new(0);
+
+    let chain = BeaconChain::genesis(state_store, block_store, slot_clock, spec);
+    (db, chain.unwrap())
+}
+
+#[test]
+fn it_constructs() {
+    let (_db, _chain) = in_memory_test_chain(ChainSpec::foundation());
+}
+
+#[test]
+fn it_produces() {
+    let (_db, mut chain) = in_memory_test_chain(ChainSpec::foundation());
+    let (_block, _state) = chain.produce_block().unwrap();
+}
+
+#[test]
+fn it_processes_a_block_it_produces() {
+    let (_db, mut chain) = in_memory_test_chain(ChainSpec::foundation());
+    let (block, _state) = chain.produce_block().unwrap();
+    let (outcome, new_block_hash) = chain.process_block(block).unwrap();
+    assert_eq!(outcome, BlockProcessingOutcome::Processed);
+    assert_eq!(chain.canonical_leaf_block, new_block_hash);
+}