Try to initialize state with pure Altair spec in tests

specs/altair/beacon-chain.md

@@ -52,6 +52,7 @@
     - [Slashings](#slashings)
     - [Participation flags updates](#participation-flags-updates)
     - [Sync committee updates](#sync-committee-updates)
+- [Initialize state for testnets](#initialize-state-for-testnets)
 
 <!-- END doctoc generated TOC please keep comment here to allow auto update -->
 <!-- /TOC -->
@@ -661,3 +662,49 @@ def process_sync_committee_updates(state: BeaconState) -> None:
         state.current_sync_committee = state.next_sync_committee
         state.next_sync_committee = get_sync_committee(state, next_epoch + EPOCHS_PER_SYNC_COMMITTEE_PERIOD)
 ```
+
+## Initialize state for testnets
+
+This helper function is only for initialize Altair testnets and tests.
+
+```python
+def initialize_beacon_state_from_eth1(eth1_block_hash: Bytes32,
+                                      eth1_timestamp: uint64,
+                                      deposits: Sequence[Deposit]) -> BeaconState:
+    fork = Fork(
+        previous_version=GENESIS_FORK_VERSION,
+        current_version=ALTAIR_FORK_VERSION,
+        epoch=GENESIS_EPOCH,
+    )
+    state = BeaconState(
+        genesis_time=eth1_timestamp + GENESIS_DELAY,
+        fork=fork,
+        eth1_data=Eth1Data(block_hash=eth1_block_hash, deposit_count=uint64(len(deposits))),
+        latest_block_header=BeaconBlockHeader(body_root=hash_tree_root(BeaconBlockBody())),
+        randao_mixes=[eth1_block_hash] * EPOCHS_PER_HISTORICAL_VECTOR,  # Seed RANDAO with Eth1 entropy
+    )
+
+    # Process deposits
+    leaves = list(map(lambda deposit: deposit.data, deposits))
+    for index, deposit in enumerate(deposits):
+        deposit_data_list = List[DepositData, 2**DEPOSIT_CONTRACT_TREE_DEPTH](*leaves[:index + 1])
+        state.eth1_data.deposit_root = hash_tree_root(deposit_data_list)
+        process_deposit(state, deposit)
+
+    # Process activations
+    for index, validator in enumerate(state.validators):
+        balance = state.balances[index]
+        validator.effective_balance = min(balance - balance % EFFECTIVE_BALANCE_INCREMENT, MAX_EFFECTIVE_BALANCE)
+        if validator.effective_balance == MAX_EFFECTIVE_BALANCE:
+            validator.activation_eligibility_epoch = GENESIS_EPOCH
+            validator.activation_epoch = GENESIS_EPOCH
+
+    # Set genesis validators root for domain separation and chain versioning
+    state.genesis_validators_root = hash_tree_root(state.validators)
+
+    # Fill in sync committees
+    state.current_sync_committee = get_sync_committee(state, get_current_epoch(state))
+    state.next_sync_committee = get_sync_committee(state, get_current_epoch(state) + EPOCHS_PER_SYNC_COMMITTEE_PERIOD)
+
+    return state
+```

tests/core/pyspec/eth2spec/test/context.py

@@ -75,17 +75,11 @@ class SpecForks(TypedDict, total=False):
 
 def _prepare_state(balances_fn: Callable[[Any], Sequence[int]], threshold_fn: Callable[[Any], int],
                    spec: Spec, phases: SpecForks):
-
+    phase = phases[spec.fork]
-    p0 = phases[PHASE0]
+    balances = balances_fn(phase)
-    balances = balances_fn(p0)
+    activation_threshold = threshold_fn(phase)
-    activation_threshold = threshold_fn(p0)
+    state = create_genesis_state(spec=phase, validator_balances=balances,
-
-    state = create_genesis_state(spec=p0, validator_balances=balances,
                                  activation_threshold=activation_threshold)
-    # TODO: upgrade to merge spec, and later sharding.
-    if spec.fork == ALTAIR:
-        state = phases[ALTAIR].upgrade_to_altair(state)
-
     return state
 
 

tests/core/pyspec/eth2spec/test/helpers/fork_choice.py

@@ -1,7 +1,5 @@
 from eth_utils import encode_hex
 
-from eth2spec.phase0 import spec as phase0_spec
-
 
 def get_anchor_root(spec, state):
     anchor_block_header = state.latest_block_header.copy()
@@ -58,8 +56,7 @@ def get_genesis_forkchoice_store(spec, genesis_state):
 
 def get_genesis_forkchoice_store_and_block(spec, genesis_state):
     assert genesis_state.slot == spec.GENESIS_SLOT
-    # The genesis block must be a Phase 0 `BeaconBlock`
+    genesis_block = spec.BeaconBlock(state_root=genesis_state.hash_tree_root())
-    genesis_block = phase0_spec.BeaconBlock(state_root=genesis_state.hash_tree_root())
     return spec.get_forkchoice_store(genesis_state, genesis_block), genesis_block
 
 

tests/core/pyspec/eth2spec/test/helpers/genesis.py

@@ -20,6 +20,9 @@ def create_genesis_state(spec, validator_balances, activation_threshold):
     deposit_root = b'\x42' * 32
 
     eth1_block_hash = b'\xda' * 32
+    current_version = spec.GENESIS_FORK_VERSION
+    if spec.fork == 'altair':  # TODO: fix `context.py` dependency
+        current_version = spec.ALTAIR_FORK_VERSION
     state = spec.BeaconState(
         genesis_time=0,
         eth1_deposit_index=len(validator_balances),
@@ -30,7 +33,7 @@ def create_genesis_state(spec, validator_balances, activation_threshold):
         ),
         fork=spec.Fork(
             previous_version=spec.GENESIS_FORK_VERSION,
-            current_version=spec.GENESIS_FORK_VERSION,
+            current_version=current_version,
             epoch=spec.GENESIS_EPOCH,
         ),
         latest_block_header=spec.BeaconBlockHeader(body_root=spec.hash_tree_root(spec.BeaconBlockBody())),
@@ -47,8 +50,19 @@ def create_genesis_state(spec, validator_balances, activation_threshold):
         if validator.effective_balance >= activation_threshold:
             validator.activation_eligibility_epoch = spec.GENESIS_EPOCH
             validator.activation_epoch = spec.GENESIS_EPOCH
+        if spec.fork != 'phase0':  # TODO: fix `context.py` dependency
+            state.previous_epoch_participation.append(spec.ParticipationFlags(0b0000_0000))
+            state.current_epoch_participation.append(spec.ParticipationFlags(0b0000_0000))
+            state.inactivity_scores.append(spec.uint64(0))
 
     # Set genesis validators root for domain separation and chain versioning
     state.genesis_validators_root = spec.hash_tree_root(state.validators)
 
+    if spec.fork != 'phase0':  # TODO: fix `context.py` dependency
+        # Fill in sync committees
+        state.current_sync_committee = spec.get_sync_committee(state, spec.get_current_epoch(state))
+        state.next_sync_committee = (
+            spec.get_sync_committee(state, spec.get_current_epoch(state) + spec.EPOCHS_PER_SYNC_COMMITTEE_PERIOD)
+        )
+
     return state