ensure when performing optimally that you don't lose money during a leak

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

@@ -1,4 +1,5 @@
 from random import Random
+from lru import LRU
 
 from eth2spec.phase0 import spec as spec_phase0
 from eth2spec.test.helpers.attestations import cached_prepare_state_with_attestations
@@ -170,6 +171,39 @@ def run_get_inactivity_penalty_deltas(spec, state):
             assert penalties[index] == 0
 
 
+def transition_state_to_leak(spec, state, epochs=None):
+    if epochs is None:
+        epochs = spec.MIN_EPOCHS_TO_INACTIVITY_PENALTY
+    assert epochs >= spec.MIN_EPOCHS_TO_INACTIVITY_PENALTY
+
+    for _ in range(epochs):
+        next_epoch(spec, state)
+
+
+_cache_dict = LRU(size=10)
+
+
+def leaking(epochs=None):
+
+    def deco(fn):
+        def entry(*args, spec, state, **kw):
+            # If the pre-state is not already known in the LRU, then take it,
+            # transition it to leak, and put it in the LRU.
+            # The input state is likely already cached, so the hash-tree-root does not affect speed.
+            key = (state.hash_tree_root(), spec.MIN_EPOCHS_TO_INACTIVITY_PENALTY, spec.SLOTS_PER_EPOCH, epochs)
+            global _cache_dict
+            if key not in _cache_dict:
+                transition_state_to_leak(spec, state, epochs=epochs)
+                _cache_dict[key] = state.get_backing()  # cache the tree structure, not the view wrapping it.
+
+            # Take an entry out of the LRU.
+            # No copy is necessary, as we wrap the immutable backing with a new view.
+            state = spec.BeaconState(backing=_cache_dict[key])
+            return fn(*args, spec=spec, state=state, **kw)
+        return entry
+    return deco
+
+
 def set_some_new_deposits(spec, state, rng):
     num_validators = len(state.validators)
     # Set ~1/10 to just recently deposited

tests/core/pyspec/eth2spec/test/phase_0/epoch_processing/test_process_rewards_and_penalties.py

@@ -14,6 +14,7 @@ from eth2spec.test.helpers.attestations import (
     get_valid_attestation,
     prepare_state_with_attestations,
 )
+from eth2spec.test.helpers.rewards import leaking
 from eth2spec.test.helpers.attester_slashings import get_indexed_attestation_participants
 from eth2spec.test.phase_0.epoch_processing.run_epoch_process_base import run_epoch_processing_with
 from random import Random
@@ -80,6 +81,56 @@ def test_full_attestations(spec, state):
             assert state.balances[index] < pre_state.balances[index]
 
 
+@with_all_phases
+@spec_state_test
+@leaking()
+def test_full_attestations_with_leak(spec, state):
+    attestations = prepare_state_with_attestations(spec, state)
+
+    proposer_indices = [a.proposer_index for a in state.previous_epoch_attestations]
+    pre_state = state.copy()
+
+    yield from run_process_rewards_and_penalties(spec, state)
+
+    attesting_indices = spec.get_unslashed_attesting_indices(state, attestations)
+    assert len(attesting_indices) == len(pre_state.validators)
+    for index in range(len(pre_state.validators)):
+        # Proposers can still make money during a leak
+        if index in proposer_indices:
+            assert state.balances[index] > pre_state.balances[index]
+        # If not proposer but participated optimally, should have exactly neutral balance
+        elif index in attesting_indices:
+            assert state.balances[index] == pre_state.balances[index]
+        else:
+            assert state.balances[index] < pre_state.balances[index]
+
+
+@with_all_phases
+@spec_state_test
+@leaking()
+def test_partial_attestations_with_leak(spec, state):
+    attestations = prepare_state_with_attestations(spec, state)
+
+    attestations = attestations[:len(attestations) // 2]
+    state.previous_epoch_attestations = state.previous_epoch_attestations[:len(attestations)]
+    proposer_indices = [a.proposer_index for a in state.previous_epoch_attestations]
+    pre_state = state.copy()
+
+    yield from run_process_rewards_and_penalties(spec, state)
+
+    attesting_indices = spec.get_unslashed_attesting_indices(state, attestations)
+    assert len(attesting_indices) < len(pre_state.validators)
+    for index in range(len(pre_state.validators)):
+        # Proposers can still make money during a leak
+        if index in proposer_indices and index in attesting_indices:
+            assert state.balances[index] > pre_state.balances[index]
+        # If not proposer but participated optimally, should have exactly neutral balance
+        elif index in attesting_indices:
+            assert state.balances[index] == pre_state.balances[index]
+        else:
+            assert state.balances[index] < pre_state.balances[index]
+
+
 @with_all_phases
 @spec_state_test
 def test_full_attestations_random_incorrect_fields(spec, state):

tests/core/pyspec/eth2spec/test/phase_0/rewards/test_leak.py

@@ -1,40 +1,6 @@
 from eth2spec.test.context import with_all_phases, spec_state_test
-from eth2spec.test.helpers.state import next_epoch
+from eth2spec.test.helpers.rewards import leaking
 import eth2spec.test.helpers.rewards as rewards_helpers
-from lru import LRU
-
-
-def transition_state_to_leak(spec, state, epochs=None):
-    if epochs is None:
-        epochs = spec.MIN_EPOCHS_TO_INACTIVITY_PENALTY
-    assert epochs >= spec.MIN_EPOCHS_TO_INACTIVITY_PENALTY
-
-    for _ in range(epochs):
-        next_epoch(spec, state)
-
-
-_cache_dict = LRU(size=10)
-
-
-def leaking(epochs=None):
-
-    def deco(fn):
-        def entry(*args, spec, state, **kw):
-            # If the pre-state is not already known in the LRU, then take it,
-            # transition it to leak, and put it in the LRU.
-            # The input state is likely already cached, so the hash-tree-root does not affect speed.
-            key = (state.hash_tree_root(), spec.MIN_EPOCHS_TO_INACTIVITY_PENALTY, spec.SLOTS_PER_EPOCH, epochs)
-            global _cache_dict
-            if key not in _cache_dict:
-                transition_state_to_leak(spec, state, epochs=epochs)
-                _cache_dict[key] = state.get_backing()  # cache the tree structure, not the view wrapping it.
-
-            # Take an entry out of the LRU.
-            # No copy is necessary, as we wrap the immutable backing with a new view.
-            state = spec.BeaconState(backing=_cache_dict[key])
-            return fn(*args, spec=spec, state=state, **kw)
-        return entry
-    return deco
 
 
 @with_all_phases