Merge pull request #2640 from ethereum/fix-merge-gen-state

 initialize_beacon_state_from_eth1 for pre-transition merge

specs/merge/beacon-chain.md

@@ -13,7 +13,6 @@
 - [Constants](#constants)
   - [Execution](#execution)
 - [Configuration](#configuration)
-  - [Genesis testing settings](#genesis-testing-settings)
   - [Transition settings](#transition-settings)
 - [Containers](#containers)
   - [Extended containers](#extended-containers)
@@ -71,15 +70,6 @@ This patch adds transaction execution to the beacon chain as part of the Merge f
 
 ## Configuration
 
-### Genesis testing settings
-
-*Note*: These configuration settings do not apply to the mainnet and are utilized only by pure Merge testing.
-
-| Name | Value |
-| - | - |
-| `GENESIS_GAS_LIMIT` | `uint64(30000000)` (= 30,000,000) |
-| `GENESIS_BASE_FEE_PER_GAS` | `Bytes32('0x00ca9a3b00000000000000000000000000000000000000000000000000000000')` (= 1,000,000,000) |
-
 ### Transition settings
 
 | Name | Value |
@@ -354,13 +344,19 @@ def process_execution_payload(state: BeaconState, payload: ExecutionPayload, exe
 ## Testing
 
 *Note*: The function `initialize_beacon_state_from_eth1` is modified for pure Merge testing only.
-
-*Note*: The function `initialize_beacon_state_from_eth1` is modified: (1) using `MERGE_FORK_VERSION` as the current fork version, (2) utilizing the Merge `BeaconBlockBody` when constructing the initial `latest_block_header`, and (3) initialize `latest_execution_payload_header`.
+Modifications include:
+1. Use `MERGE_FORK_VERSION` as the current fork version.
+2. Utilize the Merge `BeaconBlockBody` when constructing the initial `latest_block_header`.
+3. Initialize `latest_execution_payload_header`.
+  If `execution_payload_header == ExecutionPayloadHeader()`, then the Merge has not yet occurred.
+  Else, the Merge starts from genesis and the transition is incomplete.
 
 ```python
 def initialize_beacon_state_from_eth1(eth1_block_hash: Bytes32,
                                       eth1_timestamp: uint64,
-                                      deposits: Sequence[Deposit]) -> BeaconState:
+                                      deposits: Sequence[Deposit],
+                                      execution_payload_header: ExecutionPayloadHeader=ExecutionPayloadHeader()
+                                      ) -> BeaconState:
     fork = Fork(
         previous_version=MERGE_FORK_VERSION,  # [Modified in Merge] for testing only
         current_version=MERGE_FORK_VERSION,  # [Modified in Merge]
@@ -397,12 +393,9 @@ def initialize_beacon_state_from_eth1(eth1_block_hash: Bytes32,
     state.current_sync_committee = get_next_sync_committee(state)
     state.next_sync_committee = get_next_sync_committee(state)
 
-    # [New in Merge] Initialize the execution payload header (with block number set to 0)
-    state.latest_execution_payload_header.block_hash = eth1_block_hash
-    state.latest_execution_payload_header.timestamp = eth1_timestamp
-    state.latest_execution_payload_header.random = eth1_block_hash
-    state.latest_execution_payload_header.gas_limit = GENESIS_GAS_LIMIT
-    state.latest_execution_payload_header.base_fee_per_gas = GENESIS_BASE_FEE_PER_GAS
+    # [New in Merge] 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
 ```

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

@@ -20,6 +20,25 @@ def build_mock_validator(spec, i: int, balance: int):
     )
 
 
+def get_sample_genesis_execution_payload_header(spec,
+                                                eth1_block_hash=None):
+    if eth1_block_hash is None:
+        eth1_block_hash = b'\x55' * 32
+    return spec.ExecutionPayloadHeader(
+        parent_hash=b'\x30' * 32,
+        coinbase=b'\x42' * 20,
+        state_root=b'\x20' * 32,
+        receipt_root=b'\x20' * 32,
+        logs_bloom=b'\x35' * spec.BYTES_PER_LOGS_BLOOM,
+        random=eth1_block_hash,
+        block_number=0,
+        gas_limit=30000000,
+        base_fee_per_gas=spec.Bytes32('0x00ca9a3b00000000000000000000000000000000000000000000000000000000'),
+        block_hash=eth1_block_hash,
+        transactions_root=spec.Root(b'\x56' * 32),
+    )
+
+
 def create_genesis_state(spec, validator_balances, activation_threshold):
     deposit_root = b'\x42' * 32
 
@@ -76,9 +95,9 @@ def create_genesis_state(spec, validator_balances, activation_threshold):
 
     if spec.fork not in FORKS_BEFORE_MERGE:
         # Initialize the execution payload header (with block number and genesis time set to 0)
-        state.latest_execution_payload_header.block_hash = eth1_block_hash
-        state.latest_execution_payload_header.random = eth1_block_hash
-        state.latest_execution_payload_header.gas_limit = spec.GENESIS_GAS_LIMIT
-        state.latest_execution_payload_header.base_fee_per_gas = spec.GENESIS_BASE_FEE_PER_GAS
+        state.latest_execution_payload_header = get_sample_genesis_execution_payload_header(
+            spec,
+            eth1_block_hash=eth1_block_hash,
+        )
 
     return state

tests/core/pyspec/eth2spec/test/merge/genesis/test_initialization.py

@@ -0,0 +1,122 @@
+from eth2spec.test.context import (
+    MERGE,
+    single_phase,
+    spec_test,
+    with_presets,
+    with_phases,
+    with_merge_and_later,
+)
+from eth2spec.test.helpers.constants import MINIMAL
+from eth2spec.test.helpers.deposits import (
+    prepare_full_genesis_deposits,
+)
+from eth2spec.test.helpers.genesis import (
+    get_sample_genesis_execution_payload_header,
+)
+
+
+def eth1_init_data(eth1_block_hash, eth1_timestamp):
+    yield 'eth1', {
+        'eth1_block_hash': '0x' + eth1_block_hash.hex(),
+        'eth1_timestamp': int(eth1_timestamp),
+    }
+
+
+@with_phases([MERGE])
+@spec_test
+@single_phase
+@with_presets([MINIMAL], reason="too slow")
+def test_initialize_pre_transition_no_param(spec):
+    deposit_count = spec.config.MIN_GENESIS_ACTIVE_VALIDATOR_COUNT
+    deposits, deposit_root, _ = prepare_full_genesis_deposits(
+        spec,
+        spec.MAX_EFFECTIVE_BALANCE,
+        deposit_count,
+        signed=True,
+    )
+
+    eth1_block_hash = b'\x12' * 32
+    eth1_timestamp = spec.config.MIN_GENESIS_TIME
+
+    yield from eth1_init_data(eth1_block_hash, eth1_timestamp)
+    yield 'deposits', deposits
+
+    # initialize beacon_state *without* an execution_payload_header
+    yield 'execution_payload_header', 'meta', False
+    state = spec.initialize_beacon_state_from_eth1(eth1_block_hash, eth1_timestamp, deposits)
+
+    assert not spec.is_merge_complete(state)
+
+    yield 'state', state
+
+
+@with_merge_and_later
+@spec_test
+@single_phase
+@with_presets([MINIMAL], reason="too slow")
+def test_initialize_pre_transition_empty_payload(spec):
+    deposit_count = spec.config.MIN_GENESIS_ACTIVE_VALIDATOR_COUNT
+    deposits, deposit_root, _ = prepare_full_genesis_deposits(
+        spec,
+        spec.MAX_EFFECTIVE_BALANCE,
+        deposit_count,
+        signed=True,
+    )
+
+    eth1_block_hash = b'\x12' * 32
+    eth1_timestamp = spec.config.MIN_GENESIS_TIME
+
+    yield from eth1_init_data(eth1_block_hash, eth1_timestamp)
+    yield 'deposits', deposits
+
+    # initialize beacon_state *with* an *empty* execution_payload_header
+    yield 'execution_payload_header', 'meta', True
+    execution_payload_header = spec.ExecutionPayloadHeader()
+    state = spec.initialize_beacon_state_from_eth1(
+        eth1_block_hash,
+        eth1_timestamp,
+        deposits,
+        execution_payload_header=execution_payload_header,
+    )
+
+    assert not spec.is_merge_complete(state)
+
+    yield 'execution_payload_header', execution_payload_header
+
+    yield 'state', state
+
+
+@with_merge_and_later
+@spec_test
+@single_phase
+@with_presets([MINIMAL], reason="too slow")
+def test_initialize_post_transition(spec):
+    deposit_count = spec.config.MIN_GENESIS_ACTIVE_VALIDATOR_COUNT
+    deposits, deposit_root, _ = prepare_full_genesis_deposits(
+        spec,
+        spec.MAX_EFFECTIVE_BALANCE,
+        deposit_count,
+        signed=True,
+    )
+
+    eth1_block_hash = b'\x12' * 32
+    eth1_timestamp = spec.config.MIN_GENESIS_TIME
+
+    yield from eth1_init_data(eth1_block_hash, eth1_timestamp)
+    yield 'deposits', deposits
+
+    # initialize beacon_state *with* an execution_payload_header
+    yield 'execution_payload_header', 'meta', True
+    genesis_execution_payload_header = get_sample_genesis_execution_payload_header(spec)
+    state = spec.initialize_beacon_state_from_eth1(
+        eth1_block_hash,
+        eth1_timestamp,
+        deposits,
+        execution_payload_header=genesis_execution_payload_header,
+    )
+
+    yield 'execution_payload_header', genesis_execution_payload_header
+
+    assert spec.is_merge_complete(state)
+
+    yield 'state', state

tests/formats/genesis/initialization.md

@@ -17,20 +17,26 @@ eth1_timestamp: int       -- An integer. The timestamp of the block, in seconds.
 A yaml file to help read the deposit count:
 
 ```yaml
-description: string    -- Optional. Description of test case, purely for debugging purposes.
-deposits_count: int    -- Amount of deposits.
+description: string             -- Optional. Description of test case, purely for debugging purposes.
+deposits_count: int             -- Amount of deposits.
+execution_payload_header: bool  -- `execution_payload_header` field is filled or not. If `true`, `execution_payload_header.ssz_snappy` file exists.
 ```
 
 ### `deposits_<index>.ssz_snappy`
 
 A series of files, with `<index>` in range `[0, deposits_count)`. Deposits need to be processed in order.
 Each file is a SSZ-snappy encoded `Deposit` object.
 
+###  `execution_payload_header.ssz_snappy`
+
+*Note*: Param added only for the Merge and subsequent forks.
+
+The execution payload header that state is initialized with. An SSZ-snappy encoded `BeaconState` object.
+
 ###  `state.ssz_snappy`
 
 The expected genesis state. An SSZ-snappy encoded `BeaconState` object.
 
-
 ## Processing
 
 To process this test, build a genesis state with the provided `eth1_block_hash`, `eth1_timestamp` and `deposits`:

tests/generators/genesis/main.py

@@ -9,7 +9,12 @@
     ]}
     altair_mods = phase_0_mods
     # we have new unconditional lines in `initialize_beacon_state_from_eth1` and we want to test it
-    merge_mods = altair_mods
+    merge_mods = {
+        **{key: 'eth2spec.test.merge.genesis.test_' + key for key in [
+            'initialization',
+        ]},
+        **altair_mods,
+    }
     all_mods = {
         PHASE0: phase_0_mods,
         ALTAIR: altair_mods,