From 9c798806355f67a32704a8cd5a98d90deccb8f69 Mon Sep 17 00:00:00 2001
From: Hsiao-Wei Wang <hsiaowei.eth@gmail.com>
Date: Fri, 15 Jul 2022 22:18:33 +0800
Subject: [PATCH] Fix genesis testing tool and add Capella version
 `initialize_beacon_state_from_eth1` helper

---
 specs/capella/beacon-chain.md                 | 57 +++++++++++++++++++
 .../pyspec/eth2spec/test/helpers/genesis.py   |  5 +-
 2 files changed, 61 insertions(+), 1 deletion(-)

diff --git a/specs/capella/beacon-chain.md b/specs/capella/beacon-chain.md
index da67a8fcb..ca0305f04 100644
--- a/specs/capella/beacon-chain.md
+++ b/specs/capella/beacon-chain.md
@@ -43,6 +43,7 @@
     - [Modified `process_execution_payload`](#modified-process_execution_payload)
     - [Modified `process_operations`](#modified-process_operations)
     - [New `process_bls_to_execution_change`](#new-process_bls_to_execution_change)
+- [Testing](#testing)
 
 <!-- END doctoc generated TOC please keep comment here to allow auto update -->
 <!-- /TOC -->
@@ -489,3 +490,59 @@ def process_bls_to_execution_change(state: BeaconState,
         + address_change.to_execution_address
     )
 ```
+
+## Testing
+
+*Note*: The function `initialize_beacon_state_from_eth1` is modified for pure Capella testing only.
+Modifications include:
+1. Use `CAPELLA_FORK_VERSION` as the current fork version.
+2. Utilize the Capella `BeaconBlockBody` when constructing the initial `latest_block_header`.
+
+```python
+def initialize_beacon_state_from_eth1(eth1_block_hash: Hash32,
+                                      eth1_timestamp: uint64,
+                                      deposits: Sequence[Deposit],
+                                      execution_payload_header: ExecutionPayloadHeader=ExecutionPayloadHeader()
+                                      ) -> BeaconState:
+    fork = Fork(
+        previous_version=CAPELLA_FORK_VERSION,  # [Modified in Capella] for testing only
+        current_version=CAPELLA_FORK_VERSION,  # [Modified in Capella]
+        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
+    # Note: A duplicate committee is assigned for the current and next committee at genesis
+    state.current_sync_committee = get_next_sync_committee(state)
+    state.next_sync_committee = get_next_sync_committee(state)
+
+    # Initialize the execution payload header
+    # If empty, will initialize a chain that has not yet gone through the Merge transition
+    state.latest_execution_payload_header = execution_payload_header
+
+    return state
+```
diff --git a/tests/core/pyspec/eth2spec/test/helpers/genesis.py b/tests/core/pyspec/eth2spec/test/helpers/genesis.py
index 83994c409..e9ef66711 100644
--- a/tests/core/pyspec/eth2spec/test/helpers/genesis.py
+++ b/tests/core/pyspec/eth2spec/test/helpers/genesis.py
@@ -1,5 +1,5 @@
 from eth2spec.test.helpers.constants import (
-    ALTAIR, BELLATRIX,
+    ALTAIR, BELLATRIX, CAPELLA,
     FORKS_BEFORE_ALTAIR, FORKS_BEFORE_BELLATRIX, FORKS_BEFORE_CAPELLA,
 )
 from eth2spec.test.helpers.keys import pubkeys
@@ -57,6 +57,9 @@ def create_genesis_state(spec, validator_balances, activation_threshold):
     elif spec.fork == BELLATRIX:
         previous_version = spec.config.ALTAIR_FORK_VERSION
         current_version = spec.config.BELLATRIX_FORK_VERSION
+    elif spec.fork == CAPELLA:
+        previous_version = spec.config.BELLATRIX_FORK_VERSION
+        current_version = spec.config.CAPELLA_FORK_VERSION
 
     state = spec.BeaconState(
         genesis_time=0,