Generalise fork choice tests.

eth2/fork_choice/tests/tests.rs

@@ -0,0 +1,257 @@
+// Tests the optimised LMD Ghost Algorithm
+
+extern crate beacon_chain;
+extern crate bls;
+extern crate db;
+extern crate env_logger;
+extern crate fork_choice;
+extern crate log;
+extern crate slot_clock;
+extern crate types;
+extern crate yaml_rust;
+
+pub use beacon_chain::BeaconChain;
+use bls::{PublicKey, Signature};
+use db::stores::{BeaconBlockStore, BeaconStateStore};
+use db::MemoryDB;
+use env_logger::{Builder, Env};
+use fork_choice::{ForkChoice, ForkChoiceAlgorithm, LongestChain, OptimisedLMDGhost, SlowLMDGhost};
+use ssz::ssz_encode;
+use std::collections::HashMap;
+use std::sync::Arc;
+use std::{fs::File, io::prelude::*, path::PathBuf};
+use types::{
+    BeaconBlock, BeaconBlockBody, BeaconState, ChainSpec, Epoch, Eth1Data, Hash256, Slot, Validator,
+};
+use yaml_rust::yaml;
+
+// run tests
+#[test]
+fn test_optimised_lmd_ghost() {
+    test_yaml_vectors(
+        ForkChoiceAlgorithm::OptimisedLMDGhost,
+        "tests/optimised_lmd_ghost_test_vectors.yaml",
+        100,
+    );
+}
+
+// run a generic test over given YAML test vectors
+fn test_yaml_vectors(
+    fork_choice_algo: ForkChoiceAlgorithm,
+    yaml_file_path: &str,
+    max_validators: usize,
+) {
+    // set up logging
+    Builder::from_env(Env::default().default_filter_or("debug")).init();
+
+    // load test cases from yaml
+    let test_cases = load_test_cases_from_yaml(yaml_file_path);
+
+    // set up the test
+    let total_emulated_validators = max_validators; // the number of validators used to give weights.
+    let (mut fork_choice, block_store, state_root) =
+        setup_inital_state(fork_choice_algo, total_emulated_validators);
+
+    // keep a hashmap of block_id's to block_hashes (random hashes to abstract block_id)
+    let mut block_id_map: HashMap<String, Hash256> = HashMap::new();
+    // keep a list of hash to slot
+    let mut block_slot: HashMap<Hash256, Slot> = HashMap::new();
+
+    // default vars
+    let spec = ChainSpec::foundation();
+    let zero_hash = Hash256::zero();
+    let eth1_data = Eth1Data {
+        deposit_root: zero_hash.clone(),
+        block_hash: zero_hash.clone(),
+    };
+    let randao_reveal = Signature::empty_signature();
+    let signature = Signature::empty_signature();
+    let body = BeaconBlockBody {
+        proposer_slashings: vec![],
+        attester_slashings: vec![],
+        attestations: vec![],
+        deposits: vec![],
+        exits: vec![],
+    };
+
+    // process the tests
+    for test_case in test_cases {
+        // assume the block tree is given to us in order.
+        for block in test_case["blocks"].clone().into_vec().unwrap() {
+            let block_id = block["id"].as_str().unwrap().to_string();
+            let parent_id = block["parent"].as_str().unwrap();
+
+            // default params for genesis
+            let mut block_hash = zero_hash.clone();
+            let mut slot = spec.genesis_slot;
+            let mut parent_root = zero_hash;
+
+            // set the slot and parent based off the YAML. Start with genesis;
+            // if not the genesis, update slot and parent
+            if parent_id != block_id {
+                // generate a random hash for the block_hash
+                block_hash = Hash256::random();
+                // find the parent hash
+                parent_root = *block_id_map
+                    .get(parent_id)
+                    .expect(&format!("Parent not found: {}", parent_id));
+                slot = *(block_slot
+                    .get(&parent_root)
+                    .expect("Parent should have a slot number"))
+                    + 1;
+            }
+
+            block_id_map.insert(block_id.clone(), block_hash.clone());
+
+            // update slot mapping
+            block_slot.insert(block_hash, slot);
+
+            // build the BeaconBlock
+            let beacon_block = BeaconBlock {
+                slot,
+                parent_root,
+                state_root: state_root.clone(),
+                randao_reveal: randao_reveal.clone(),
+                eth1_data: eth1_data.clone(),
+                signature: signature.clone(),
+                body: body.clone(),
+            };
+
+            // Store the block and state.
+            block_store
+                .put(&block_hash, &ssz_encode(&beacon_block)[..])
+                .unwrap();
+
+            // run add block for fork choice if not genesis
+            if parent_id != block_id {
+                fork_choice
+                    .add_block(&beacon_block, &block_hash, &spec)
+                    .unwrap();
+            }
+        }
+
+        // add the weights (attestations)
+        let mut current_validator = 0;
+        for id_map in test_case["weights"].clone().into_vec().unwrap() {
+            // get the block id and weights
+            for (map_id, map_weight) in id_map.as_hash().unwrap().iter() {
+                let id = map_id.as_str().unwrap();
+                let block_root = block_id_map
+                    .get(id)
+                    .expect(&format!("Cannot find block id: {} in weights", id));
+                let weight = map_weight.as_i64().unwrap();
+                // we assume a validator has a value 1 and add an attestation for to achieve the
+                // correct weight
+                for _ in 0..weight {
+                    assert!(current_validator <= total_emulated_validators);
+                    fork_choice
+                        .add_attestation(current_validator as u64, &block_root, &spec)
+                        .unwrap();
+                    current_validator += 1;
+                }
+            }
+        }
+
+        // everything is set up, run the fork choice, using genesis as the head
+        let head = fork_choice.find_head(&zero_hash, &spec).unwrap();
+
+        let (found_id, _) = block_id_map
+            .iter()
+            .find(|(_, hash)| **hash == head)
+            .unwrap();
+
+        // compare the result to the expected test
+        let success = test_case["heads"]
+            .clone()
+            .into_vec()
+            .unwrap()
+            .iter()
+            .find(|heads| heads["id"].as_str().unwrap() == found_id)
+            .is_some();
+
+        println!("Head Block ID: {:?}", found_id);
+        assert!(success, "Did not find one of the possible heads");
+    }
+}
+
+// loads the test_cases from the supplied yaml file
+fn load_test_cases_from_yaml(file_path: &str) -> Vec<yaml_rust::Yaml> {
+    // load the yaml
+    let mut file = {
+        let mut file_path_buf = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+        file_path_buf.push(file_path);
+        File::open(file_path_buf).unwrap()
+    };
+    let mut yaml_str = String::new();
+    file.read_to_string(&mut yaml_str).unwrap();
+    let docs = yaml::YamlLoader::load_from_str(&yaml_str).unwrap();
+    let doc = &docs[0];
+    doc["test_cases"].as_vec().unwrap().clone()
+}
+
+// initialise a single validator and state. All blocks will reference this state root.
+fn setup_inital_state(
+    fork_choice_algo: ForkChoiceAlgorithm,
+    no_validators: usize,
+) -> (Box<ForkChoice>, Arc<BeaconBlockStore<MemoryDB>>, Hash256) {
+    let zero_hash = Hash256::zero();
+
+    let db = Arc::new(MemoryDB::open());
+    let block_store = Arc::new(BeaconBlockStore::new(db.clone()));
+    let state_store = Arc::new(BeaconStateStore::new(db.clone()));
+
+    // the fork choice instantiation
+    let fork_choice: Box<ForkChoice> = match fork_choice_algo {
+        ForkChoiceAlgorithm::OptimisedLMDGhost => Box::new(OptimisedLMDGhost::new(
+            block_store.clone(),
+            state_store.clone(),
+        )),
+        ForkChoiceAlgorithm::SlowLMDGhost => {
+            Box::new(SlowLMDGhost::new(block_store.clone(), state_store.clone()))
+        }
+        ForkChoiceAlgorithm::LongestChain => Box::new(LongestChain::new(block_store.clone())),
+    };
+
+    // misc vars for setting up the state
+    let genesis_time = 1_550_381_159;
+
+    let latest_eth1_data = Eth1Data {
+        deposit_root: zero_hash.clone(),
+        block_hash: zero_hash.clone(),
+    };
+
+    let initial_validator_deposits = vec![];
+    let spec = ChainSpec::foundation();
+
+    // create the state
+    let mut state = BeaconState::genesis(
+        genesis_time,
+        initial_validator_deposits,
+        latest_eth1_data,
+        &spec,
+    )
+    .unwrap();
+
+    let default_validator = Validator {
+        pubkey: PublicKey::default(),
+        withdrawal_credentials: zero_hash,
+        activation_epoch: Epoch::from(0u64),
+        exit_epoch: spec.far_future_epoch,
+        withdrawal_epoch: spec.far_future_epoch,
+        penalized_epoch: spec.far_future_epoch,
+        status_flags: None,
+    };
+    // activate the validators
+    for _ in 0..no_validators {
+        state.validator_registry.push(default_validator.clone());
+        state.validator_balances.push(32_000_000_000);
+    }
+
+    let state_root = state.canonical_root();
+    state_store
+        .put(&state_root, &ssz_encode(&state)[..])
+        .unwrap();
+
+    // return initialised vars
+    (fork_choice, block_store, state_root)
+}