Add optimistic sync tests

sync/optimistic.md

@@ -88,8 +88,8 @@ Let `current_slot: Slot` be `(time - genesis_time) // SECONDS_PER_SLOT` where
 class OptimisticStore(object):
     optimistic_roots: Set[Root]
     head_block_root: Root
-    blocks: Dict[Root, BeaconBlock]
-    block_states: Dict[Root, BeaconState]
+    blocks: Dict[Root, BeaconBlock] = field(default_factory=dict)
+    block_states: Dict[Root, BeaconState] = field(default_factory=dict)
 ```
 
 ```python

tests/core/pyspec/eth2spec/gen_helpers/gen_base/gen_runner.py

@@ -9,7 +9,6 @@
 import json
 from typing import Iterable, AnyStr, Any, Callable
 import traceback
-
 from ruamel.yaml import (
     YAML,
 )
@@ -98,6 +97,11 @@ def run_generator(generator_name, test_providers: Iterable[TestProvider]):
     yaml = YAML(pure=True)
     yaml.default_flow_style = None
 
+    def _represent_none(self, _):
+        return self.represent_scalar('tag:yaml.org,2002:null', 'null')
+
+    yaml.representer.add_representer(type(None), _represent_none)
+
     # Spec config is using a YAML subset
     cfg_yaml = YAML(pure=True)
     cfg_yaml.default_flow_style = False  # Emit separate line for each key

tests/core/pyspec/eth2spec/test/bellatrix/sync/test_optimistic.py

@@ -0,0 +1,99 @@
+from eth2spec.test.context import (
+    spec_state_test,
+    with_bellatrix_and_later,
+)
+from eth2spec.test.helpers.attestations import (
+    state_transition_with_full_block,
+)
+from eth2spec.test.helpers.block import (
+    build_empty_block_for_next_slot,
+)
+from eth2spec.test.helpers.fork_choice import (
+    get_genesis_forkchoice_store_and_block,
+    on_tick_and_append_step,
+)
+from eth2spec.test.helpers.optimistic_sync import (
+    PayloadStatusV1,
+    PayloadStatusV1Status,
+    MegaStore,
+    add_optimistic_block,
+    get_optimistic_store,
+)
+from eth2spec.test.helpers.state import (
+    next_epoch,
+    state_transition_and_sign_block,
+)
+
+
+@with_bellatrix_and_later
+@spec_state_test
+def test_from_syncing_to_invalid(spec, state):
+    test_steps = []
+    # Initialization
+    fc_store, anchor_block = get_genesis_forkchoice_store_and_block(spec, state)
+    op_store = get_optimistic_store(spec, state, anchor_block)
+    mega_store = MegaStore(spec, fc_store, op_store)
+    yield 'anchor_state', state
+    yield 'anchor_block', anchor_block
+
+    next_epoch(spec, state)
+
+    current_time = (
+        (spec.SAFE_SLOTS_TO_IMPORT_OPTIMISTICALLY * 10 + state.slot) * spec.config.SECONDS_PER_SLOT
+        + fc_store.genesis_time
+    )
+    on_tick_and_append_step(spec, fc_store, current_time, test_steps)
+
+    # Block 0
+    block_0 = build_empty_block_for_next_slot(spec, state)
+    block_0.body.execution_payload.block_hash = spec.hash(bytes(f'block_0', 'UTF-8'))
+    signed_block = state_transition_and_sign_block(spec, state, block_0)
+    yield from add_optimistic_block(spec, mega_store, signed_block, test_steps, status=PayloadStatusV1Status.VALID)
+    assert spec.get_head(mega_store.fc_store) == mega_store.opt_store.head_block_root
+
+    state_0 = state.copy()
+
+    # Create VALID chain `a`
+    signed_blocks_a = []
+    for i in range(3):
+        block = build_empty_block_for_next_slot(spec, state)
+        block.body.execution_payload.block_hash = spec.hash(bytes(f'chain_a_{i}', 'UTF-8'))
+        block.body.execution_payload.parent_hash = (
+            spec.hash(bytes(f'chain_a_{i - 1}', 'UTF-8')) if i != 0 else block_0.body.execution_payload.block_hash
+        )
+
+        signed_block = state_transition_and_sign_block(spec, state, block)
+        yield from add_optimistic_block(spec, mega_store, signed_block, test_steps, status=PayloadStatusV1Status.VALID)
+        assert spec.get_head(mega_store.fc_store) == mega_store.opt_store.head_block_root
+        signed_blocks_a.append(signed_block.copy())
+
+    # Create SYNCING chain `b`
+    signed_blocks_b = []
+    state = state_0.copy()
+    for i in range(3):
+        block = build_empty_block_for_next_slot(spec, state)
+        block.body.execution_payload.block_hash = spec.hash(bytes(f'chain_b_{i}', 'UTF-8'))
+        block.body.execution_payload.parent_hash = (
+            spec.hash(bytes(f'chain_b_{i - 1}', 'UTF-8')) if i != 0 else block_0.body.execution_payload.block_hash
+        )
+        signed_block = state_transition_with_full_block(spec, state, True, True, block=block)
+        signed_blocks_b.append(signed_block.copy())
+        yield from add_optimistic_block(spec, mega_store, signed_block, test_steps,
+                                        status=PayloadStatusV1Status.SYNCING)
+        assert spec.get_head(mega_store.fc_store) == mega_store.opt_store.head_block_root
+
+    # Now add block 4 to chain `b` with INVALID
+    block = build_empty_block_for_next_slot(spec, state)
+    block.body.execution_payload.block_hash = spec.hash(bytes(f'chain_b_3', 'UTF-8'))
+    block.body.execution_payload.parent_hash = signed_blocks_b[-1].message.body.execution_payload.block_hash
+    signed_block = state_transition_and_sign_block(spec, state, block)
+    payload_status = PayloadStatusV1(
+        status=PayloadStatusV1Status.INVALID,
+        latest_valid_hash=block_0.body.execution_payload.block_hash,
+        validation_error="invalid",
+    )
+    yield from add_optimistic_block(spec, mega_store, signed_block, test_steps,
+                                    payload_status=payload_status)
+    assert mega_store.opt_store.head_block_root == signed_blocks_a[-1].message.hash_tree_root()
+
+    yield 'steps', test_steps

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

@@ -251,11 +251,13 @@ def state_transition_with_full_block(spec,
                                      fill_cur_epoch,
                                      fill_prev_epoch,
                                      participation_fn=None,
-                                     sync_aggregate=None):
+                                     sync_aggregate=None,
+                                     block=None):
     """
     Build and apply a block with attestions at the calculated `slot_to_attest` of current epoch and/or previous epoch.
     """
-    block = build_empty_block_for_next_slot(spec, state)
+    if block is None:
+        block = build_empty_block_for_next_slot(spec, state)
     if fill_cur_epoch and state.slot >= spec.MIN_ATTESTATION_INCLUSION_DELAY:
         slot_to_attest = state.slot - spec.MIN_ATTESTATION_INCLUSION_DELAY + 1
         if slot_to_attest >= spec.compute_start_slot_at_epoch(spec.get_current_epoch(state)):

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

@@ -13,18 +13,8 @@ def get_anchor_root(spec, state):
     return spec.hash_tree_root(anchor_block_header)
 
 
-def add_block_to_store(spec, store, signed_block):
-    pre_state = store.block_states[signed_block.message.parent_root]
-    block_time = pre_state.genesis_time + signed_block.message.slot * spec.config.SECONDS_PER_SLOT
-
-    if store.time < block_time:
-        spec.on_tick(store, block_time)
-
-    spec.on_block(store, signed_block)
-
-
 def tick_and_add_block(spec, store, signed_block, test_steps, valid=True,
-                       merge_block=False, block_not_found=False):
+                       merge_block=False, block_not_found=False, is_optimistic=False):
     pre_state = store.block_states[signed_block.message.parent_root]
     block_time = pre_state.genesis_time + signed_block.message.slot * spec.config.SECONDS_PER_SLOT
     if merge_block:
@@ -37,6 +27,7 @@ def tick_and_add_block(spec, store, signed_block, test_steps, valid=True,
         spec, store, signed_block, test_steps,
         valid=valid,
         block_not_found=block_not_found,
+        is_optimistic=is_optimistic,
     )
 
     return post_state
@@ -119,28 +110,36 @@ def add_block(spec,
               signed_block,
               test_steps,
               valid=True,
-              block_not_found=False):
+              block_not_found=False,
+              is_optimistic=False):
     """
     Run on_block and on_attestation
     """
     yield get_block_file_name(signed_block), signed_block
 
     if not valid:
-        try:
+        if is_optimistic:
             run_on_block(spec, store, signed_block, valid=True)
-        except (AssertionError, BlockNotFoundException) as e:
-            if isinstance(e, BlockNotFoundException) and not block_not_found:
-                assert False
             test_steps.append({
                 'block': get_block_file_name(signed_block),
                 'valid': False,
             })
-            return
         else:
-            assert False
-
-    run_on_block(spec, store, signed_block, valid=True)
-    test_steps.append({'block': get_block_file_name(signed_block)})
+            try:
+                run_on_block(spec, store, signed_block, valid=True)
+            except (AssertionError, BlockNotFoundException) as e:
+                if isinstance(e, BlockNotFoundException) and not block_not_found:
+                    assert False
+                test_steps.append({
+                    'block': get_block_file_name(signed_block),
+                    'valid': False,
+                })
+                return
+            else:
+                assert False
+    else:
+        run_on_block(spec, store, signed_block, valid=True)
+        test_steps.append({'block': get_block_file_name(signed_block)})
 
     # An on_block step implies receiving block's attestations
     for attestation in signed_block.message.body.attestations:
@@ -153,25 +152,26 @@ def add_block(spec,
     block_root = signed_block.message.hash_tree_root()
     assert store.blocks[block_root] == signed_block.message
     assert store.block_states[block_root].hash_tree_root() == signed_block.message.state_root
-    test_steps.append({
-        'checks': {
-            'time': int(store.time),
-            'head': get_formatted_head_output(spec, store),
-            'justified_checkpoint': {
-                'epoch': int(store.justified_checkpoint.epoch),
-                'root': encode_hex(store.justified_checkpoint.root),
-            },
-            'finalized_checkpoint': {
-                'epoch': int(store.finalized_checkpoint.epoch),
-                'root': encode_hex(store.finalized_checkpoint.root),
-            },
-            'best_justified_checkpoint': {
-                'epoch': int(store.best_justified_checkpoint.epoch),
-                'root': encode_hex(store.best_justified_checkpoint.root),
-            },
-            'proposer_boost_root': encode_hex(store.proposer_boost_root),
-        }
-    })
+    if not is_optimistic:
+        test_steps.append({
+            'checks': {
+                'time': int(store.time),
+                'head': get_formatted_head_output(spec, store),
+                'justified_checkpoint': {
+                    'epoch': int(store.justified_checkpoint.epoch),
+                    'root': encode_hex(store.justified_checkpoint.root),
+                },
+                'finalized_checkpoint': {
+                    'epoch': int(store.finalized_checkpoint.epoch),
+                    'root': encode_hex(store.finalized_checkpoint.root),
+                },
+                'best_justified_checkpoint': {
+                    'epoch': int(store.best_justified_checkpoint.epoch),
+                    'root': encode_hex(store.best_justified_checkpoint.root),
+                },
+                'proposer_boost_root': encode_hex(store.proposer_boost_root),
+            }
+        })
 
     return store.block_states[signed_block.message.hash_tree_root()]