add most attestation validations including tests

Author: djrtwo

eth/beacon/state_machines/validation.py

@@ -1,26 +1,27 @@
-from typing import (
-    Sequence,
-)
-
 from eth_typing import (
     Hash32
 )
 from eth_utils import (
     ValidationError,
 )
+from eth.constants import (
+    ZERO_HASH32,
+)
 
 
 from eth.beacon.helpers import (
     get_block_hash,
 )
 from eth.beacon.types.states import BeaconState  # noqa: F401
+from eth.beacon.types.attestations import Attestation  # noqa: F401
+from eth.beacon.types.attestation_data import AttestationData  # noqa: F401
 
 
 #
 # Attestation validation
 #
 def validate_attestation(state: BeaconState,
-                         attestation: 'AttestationRecord',
+                         attestation: Attestation,
                          epoch_length: int,
                          min_attestation_inclusion_delay: int,
                          is_validating_signatures: bool=True) -> None:
@@ -54,18 +55,22 @@ def validate_attestation(state: BeaconState,
     )
 
     validate_attestation_latest_crosslink_root(
-        attestation,
-        state.latest_crosslinks[attestation.data.shard].shard_block_root,
+        attestation_data=attestation.data,
+        latest_crosslink_shard_block_root=(
+            state.latest_crosslinks[attestation.data.shard].shard_block_root
+        ),
     )
 
+    validate_attestation_shard_block_root(attestation_data=attestation.data)
+
     if is_validating_signatures:
         validate_attestation_aggregate_signature(
             state,
             attestation,
         )
 
 
-def validate_attestation_slot(attestation_data: 'AttestationData',
+def validate_attestation_slot(attestation_data: AttestationData,
                               current_slot: int,
                               epoch_length: int,
                               min_attestation_inclusion_delay: int) -> None:
@@ -97,35 +102,43 @@ def validate_attestation_slot(attestation_data: 'AttestationData',
         )
 
 
-def validate_attestation_justified_slot(attestation_data: 'AttestationData',
+def validate_attestation_justified_slot(attestation_data: AttestationData,
                                         current_slot: int,
                                         previous_justified_slot: int,
                                         justified_slot: int,
                                         epoch_length: int) -> None:
+    """
+    Validate ``justified_slot`` field of ``attestation_data``.
+    Raise ``ValidationError`` if it's invalid.
+    """
     if attestation_data.slot >= current_slot - (current_slot % epoch_length):
         if attestation_data.justified_slot != justified_slot:
             raise ValidationError(
-                "Attestation slot is after recent epoch transition but "
-                "is not targeting the justified slot:\n"
+                "Attestation ``slot`` is after recent epoch transition but attestation"
+                "``justified_slot`` is not targeting the ``justified_slot``:\n"
                 "\tFound: %s, Expected %s" %
                 (attestation_data.justified_slot, justified_slot)
             )
     else:
         if attestation_data.justified_slot != previous_justified_slot:
             raise ValidationError(
-                "Attestation slot is before recent epoch transition but "
-                "is not targeting the previous justified slot:\n"
+                "Attestation ``slot`` is before recent epoch transition but attestation"
+                "``justified_slot`` is not targeting the ``previous_justified_slot:\n"
                 "\tFound: %s, Expected %s" %
                 (attestation_data.justified_slot, previous_justified_slot)
             )
 
 
-def validate_attestation_justified_block_root(attestation_data: 'AttestationData',
+def validate_attestation_justified_block_root(attestation_data: AttestationData,
                                               justified_block_root: Hash32) -> None:
+    """
+    Validate ``justified_block_hash`` field of ``attestation_data``.
+    Raise ``ValidationError`` if it's invalid.
+    """
     if attestation_data.justified_block_hash != justified_block_root:
         raise ValidationError(
-            "Attestation justified block root is not equal to the block root at the "
-            "justified slot:\n"
+            "Attestation ``justified_block_hash`` is not equal to the "
+            "``justified_block_root`` at the ``justified_slot``:\n"
             "\tFound: %s, Expected %s at slot %s" %
             (
                 attestation_data.justified_block_hash,
@@ -135,11 +148,49 @@ def validate_attestation_justified_block_root(attestation_data: 'AttestationData
         )
 
 
-def validate_attestation_latest_crosslink_root(attestation_data: 'AttestationData',
+def validate_attestation_latest_crosslink_root(attestation_data: AttestationData,
                                                latest_crosslink_shard_block_root: Hash32) -> None:
-    pass
+    """
+    Validate that either the ``latest_crosslink_hash`` or ``shard_block_hash``
+    field of ``attestation_data`` is the provided ``latest_crosslink_shard_block_root``.
+    Raise ``ValidationError`` if it's invalid.
+    """
+    acceptable_shard_block_roots = [
+        attestation_data.latest_crosslink_hash,
+        attestation_data.shard_block_hash,
+    ]
+    if latest_crosslink_shard_block_root not in acceptable_shard_block_roots:
+        raise ValidationError(
+            "Neither the attestation ``latest_crosslink_hash`` nor the attestation "
+            "``shard_block_hash`` are equal to the ``latest_crosslink_shard_block_root``.\n"
+            "\tFound: %s and %s, Expected %s" %
+            (
+                attestation_data.latest_crosslink_hash,
+                attestation_data.shard_block_hash,
+                latest_crosslink_shard_block_root,
+            )
+        )
+
+
+def validate_attestation_shard_block_root(attestation_data: AttestationData) -> None:
+    """
+    Validate ``shard_block_hash`` field of `attestation_data`.
+    Raise ``ValidationError`` if it's invalid.
+
+    Note: This is the Phase 0 version of ``shard_block_hash`` validation.
+    This is a built-in stub and will be changed in phase 1.
+    """
+    if attestation_data.shard_block_hash != ZERO_HASH32:
+        raise ValidationError(
+            "Attestation ``shard_block_hash`` is not ZERO_HASH32.\n"
+            "\tFound: %s, Expected %s" %
+            (
+                attestation_data.shard_block_hash,
+                ZERO_HASH32,
+            )
+        )
 
 
 def validate_attestation_aggregate_signature(state: BeaconState,
-                                             attestation: 'AttestationRecord') -> None:
+                                             attestation: Attestation) -> None:
     pass

tests/beacon/state_machines/test_attestation_validation.py

@@ -3,11 +3,16 @@
 from eth_utils import (
     ValidationError,
 )
+from eth.constants import (
+    ZERO_HASH32,
+)
 
 from eth.beacon.state_machines.validation import (
-    validate_attestation_slot,
+    validate_attestation_latest_crosslink_root,
     validate_attestation_justified_block_root,
     validate_attestation_justified_slot,
+    validate_attestation_shard_block_root,
+    validate_attestation_slot,
 )
 from eth.beacon.types.attestation_data import (
     AttestationData,
@@ -134,3 +139,67 @@ def test_validate_attestation_justified_block_root(sample_attestation_data_param
                 attestation_data,
                 justified_block_root
             )
+
+
+@pytest.mark.parametrize(
+    (
+        'attestation_latest_crosslink_hash,'
+        'attestation_shard_block_hash,'
+        'latest_crosslink_shard_block_root,'
+        'is_valid'
+    ),
+    [
+        (b'\x66' * 32, b'\x42' * 32, b'\x35' * 32, False),
+        (b'\x42' * 32, b'\x42' * 32, b'\x66' * 32, False),
+        (b'\x66' * 32, b'\x42' * 32, b'\x42' * 32, True),
+        (b'\x42' * 32, b'\x35' * 32, b'\x42' * 32, True),
+        (b'\x42' * 32, b'\x42' * 32, b'\x42' * 32, True),
+    ]
+)
+def test_validate_attestation_latest_crosslink_root(sample_attestation_data_params,
+                                                    attestation_latest_crosslink_hash,
+                                                    attestation_shard_block_hash,
+                                                    latest_crosslink_shard_block_root,
+                                                    is_valid):
+    sample_attestation_data_params['latest_crosslink_hash'] = attestation_latest_crosslink_hash
+    sample_attestation_data_params['shard_block_hash'] = attestation_shard_block_hash
+    attestation_data = AttestationData(**sample_attestation_data_params)
+
+    if is_valid:
+        validate_attestation_latest_crosslink_root(
+            attestation_data,
+            latest_crosslink_shard_block_root,
+        )
+    else:
+        with pytest.raises(ValidationError):
+            validate_attestation_latest_crosslink_root(
+                attestation_data,
+                latest_crosslink_shard_block_root,
+            )
+
+
+@pytest.mark.parametrize(
+    (
+        'attestation_shard_block_hash,is_valid'
+    ),
+    [
+        (ZERO_HASH32, True),
+        (b'\x35' * 32, False),
+        (b'\x66' * 32, False),
+    ]
+)
+def test_validate_attestation_shard_block_root(sample_attestation_data_params,
+                                               attestation_shard_block_hash,
+                                               is_valid):
+    sample_attestation_data_params['shard_block_hash'] = attestation_shard_block_hash
+    attestation_data = AttestationData(**sample_attestation_data_params)
+
+    if is_valid:
+        validate_attestation_shard_block_root(
+            attestation_data,
+        )
+    else:
+        with pytest.raises(ValidationError):
+            validate_attestation_shard_block_root(
+                attestation_data,
+            )