Merge pull request #2444 from ethereum/invariant-checks

Add some invariant checks to pyspec unit tests

setup.py

@@ -303,14 +303,6 @@ class SpecBuilder(ABC):
         """
         raise NotImplementedError()
 
-    @classmethod
-    @abstractmethod
-    def invariant_checks(cls) -> str:
-        """
-        The invariant checks
-        """
-        raise NotImplementedError()
-
     @classmethod
     @abstractmethod
     def implement_optimizations(cls, functions: Dict[str, str]) -> Dict[str, str]:
@@ -436,10 +428,6 @@ get_attesting_indices = cache_this(
     def hardcoded_custom_type_dep_constants(cls) -> Dict[str, str]:
         return {}
 
-    @classmethod
-    def invariant_checks(cls) -> str:
-        return ''
-
     @classmethod
     def implement_optimizations(cls, functions: Dict[str, str]) -> Dict[str, str]:
         return functions
@@ -490,13 +478,6 @@ def get_generalized_index(ssz_class: Any, *path: Sequence[Union[int, SSZVariable
         }
         return {**super().hardcoded_ssz_dep_constants(), **constants}
 
-    @classmethod
-    def invariant_checks(cls) -> str:
-        return '''
-assert (
-    TIMELY_HEAD_WEIGHT + TIMELY_SOURCE_WEIGHT + TIMELY_TARGET_WEIGHT + SYNC_REWARD_WEIGHT + PROPOSER_WEIGHT
-) == WEIGHT_DENOMINATOR'''
-
     @classmethod
     def implement_optimizations(cls, functions: Dict[str, str]) -> Dict[str, str]:
         if "eth2_aggregate_pubkeys" in functions:
@@ -668,7 +649,6 @@ def objects_to_spec(preset_name: str,
             # Since some constants are hardcoded in setup.py, the following assertions verify that the hardcoded constants are
             # as same as the spec definition.
             + ('\n\n\n' + ssz_dep_constants_verification if ssz_dep_constants_verification != '' else '')
-            + ('\n' + builder.invariant_checks() if builder.invariant_checks() != '' else '')
             + '\n'
     )
     return spec

tests/core/pyspec/eth2spec/test/altair/unittests/test_config_invariants.py

@@ -0,0 +1,23 @@
+from eth2spec.test.context import (
+    spec_state_test,
+    with_phases,
+)
+from eth2spec.test.helpers.constants import ALTAIR
+
+
+@with_phases([ALTAIR])
+@spec_state_test
+def test_weight_denominator(spec, state):
+    assert (
+        spec.TIMELY_HEAD_WEIGHT
+        + spec.TIMELY_SOURCE_WEIGHT
+        + spec.TIMELY_TARGET_WEIGHT
+        + spec.SYNC_REWARD_WEIGHT
+        + spec.PROPOSER_WEIGHT
+    ) == spec.WEIGHT_DENOMINATOR
+
+
+@with_phases([ALTAIR])
+@spec_state_test
+def test_inactivity_score(spec, state):
+    assert spec.config.INACTIVITY_SCORE_BIAS <= spec.config.INACTIVITY_SCORE_RECOVERY_RATE

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

@@ -32,3 +32,9 @@ MAINNET = PresetBaseName('mainnet')
 MINIMAL = PresetBaseName('minimal')
 
 ALL_PRESETS = (MINIMAL, MAINNET)
+
+
+#
+# Number
+#
+MAX_UINT_64 = 2**64 - 1

tests/core/pyspec/eth2spec/test/phase0/unittests/test_config_invariants.py

@@ -0,0 +1,74 @@
+from eth2spec.test.context import (
+    spec_state_test,
+    with_all_phases,
+    is_post_altair,
+)
+from eth2spec.test.helpers.constants import MAX_UINT_64
+
+
+def check_bound(value, lower_bound, upper_bound):
+    assert value >= lower_bound
+    assert value <= upper_bound
+
+
+@with_all_phases
+@spec_state_test
+def test_validators(spec, state):
+    check_bound(spec.VALIDATOR_REGISTRY_LIMIT, 1, MAX_UINT_64)
+    check_bound(spec.MAX_COMMITTEES_PER_SLOT, 1, MAX_UINT_64)
+    check_bound(spec.TARGET_COMMITTEE_SIZE, 1, MAX_UINT_64)
+
+    # Note: can be less if you assume stricters bounds on validator set based on total ETH supply
+    maximum_validators_per_committee = (
+        spec.VALIDATOR_REGISTRY_LIMIT
+        // spec.SLOTS_PER_EPOCH
+        // spec.MAX_COMMITTEES_PER_SLOT
+    )
+    check_bound(spec.MAX_VALIDATORS_PER_COMMITTEE, 1, maximum_validators_per_committee)
+    check_bound(spec.config.MIN_PER_EPOCH_CHURN_LIMIT, 1, spec.VALIDATOR_REGISTRY_LIMIT)
+    check_bound(spec.config.CHURN_LIMIT_QUOTIENT, 1, spec.VALIDATOR_REGISTRY_LIMIT)
+
+    check_bound(spec.config.MIN_GENESIS_ACTIVE_VALIDATOR_COUNT, spec.TARGET_COMMITTEE_SIZE, MAX_UINT_64)
+
+
+@with_all_phases
+@spec_state_test
+def test_balances(spec, state):
+    assert spec.MAX_EFFECTIVE_BALANCE % spec.EFFECTIVE_BALANCE_INCREMENT == 0
+    check_bound(spec.MIN_DEPOSIT_AMOUNT, 1, MAX_UINT_64)
+    check_bound(spec.MAX_EFFECTIVE_BALANCE, spec.MIN_DEPOSIT_AMOUNT, MAX_UINT_64)
+    check_bound(spec.MAX_EFFECTIVE_BALANCE, spec.EFFECTIVE_BALANCE_INCREMENT, MAX_UINT_64)
+
+
+@with_all_phases
+@spec_state_test
+def test_hysteresis_quotient(spec, state):
+    check_bound(spec.HYSTERESIS_QUOTIENT, 1, MAX_UINT_64)
+    check_bound(spec.HYSTERESIS_DOWNWARD_MULTIPLIER, 1, spec.HYSTERESIS_QUOTIENT)
+    check_bound(spec.HYSTERESIS_UPWARD_MULTIPLIER, spec.HYSTERESIS_QUOTIENT, MAX_UINT_64)
+
+
+@with_all_phases
+@spec_state_test
+def test_incentives(spec, state):
+    # Ensure no ETH is minted in slash_validator
+    if is_post_altair(spec):
+        assert spec.MIN_SLASHING_PENALTY_QUOTIENT_ALTAIR <= spec.WHISTLEBLOWER_REWARD_QUOTIENT
+    else:
+        assert spec.MIN_SLASHING_PENALTY_QUOTIENT <= spec.WHISTLEBLOWER_REWARD_QUOTIENT
+
+
+@with_all_phases
+@spec_state_test
+def test_time(spec, state):
+    assert spec.SLOTS_PER_EPOCH <= spec.SLOTS_PER_HISTORICAL_ROOT
+    assert spec.MIN_SEED_LOOKAHEAD < spec.MAX_SEED_LOOKAHEAD
+    assert spec.SLOTS_PER_HISTORICAL_ROOT % spec.SLOTS_PER_EPOCH == 0
+    check_bound(spec.SLOTS_PER_HISTORICAL_ROOT, spec.SLOTS_PER_EPOCH, MAX_UINT_64)
+    check_bound(spec.MIN_ATTESTATION_INCLUSION_DELAY, 1, spec.SLOTS_PER_EPOCH)
+
+
+@with_all_phases
+@spec_state_test
+def test_networking(spec, state):
+    assert spec.RANDOM_SUBNETS_PER_VALIDATOR <= spec.ATTESTATION_SUBNET_COUNT