Merge pull request #1747 from ethereum/rewards-rework

[Proposal] rework rewards/penalties to be more granular

specs/phase0/beacon-chain.md

@@ -110,6 +110,10 @@
     - [Helper functions](#helper-functions-1)
     - [Justification and finalization](#justification-and-finalization)
     - [Rewards and penalties](#rewards-and-penalties-1)
+      - [Helpers](#helpers)
+      - [Components of attestation deltas](#components-of-attestation-deltas)
+      - [`get_attestation_deltas`](#get_attestation_deltas)
+      - [`process_rewards_and_penalties`](#process_rewards_and_penalties)
     - [Registry updates](#registry-updates)
     - [Slashings](#slashings)
     - [Final updates](#final-updates)
@@ -1341,6 +1345,8 @@ def process_justification_and_finalization(state: BeaconState) -> None:
 
 #### Rewards and penalties
 
+##### Helpers
+
 ```python
 def get_base_reward(state: BeaconState, index: ValidatorIndex) -> Gwei:
     total_balance = get_total_active_balance(state)
@@ -1349,32 +1355,72 @@ def get_base_reward(state: BeaconState, index: ValidatorIndex) -> Gwei:
 ```
 
 ```python
-def get_attestation_deltas(state: BeaconState) -> Tuple[Sequence[Gwei], Sequence[Gwei]]:
+def get_eligible_validator_indices(state: BeaconState) -> Sequence[ValidatorIndex]:
     previous_epoch = get_previous_epoch(state)
-    total_balance = get_total_active_balance(state)
+    return [
-    rewards = [Gwei(0) for _ in range(len(state.validators))]
-    penalties = [Gwei(0) for _ in range(len(state.validators))]
-    eligible_validator_indices = [
         ValidatorIndex(index) for index, v in enumerate(state.validators)
         if is_active_validator(v, previous_epoch) or (v.slashed and previous_epoch + 1 < v.withdrawable_epoch)
     ]
+```
 
-    # Micro-incentives for matching FFG source, FFG target, and head
+```python
-    matching_source_attestations = get_matching_source_attestations(state, previous_epoch)
+def get_attestation_component_deltas(state: BeaconState,
-    matching_target_attestations = get_matching_target_attestations(state, previous_epoch)
+                                     attestations: Sequence[PendingAttestation]
-    matching_head_attestations = get_matching_head_attestations(state, previous_epoch)
+                                     ) -> Tuple[Sequence[Gwei], Sequence[Gwei]]:
-    for attestations in (matching_source_attestations, matching_target_attestations, matching_head_attestations):
+    """
+    Helper with shared logic for use by get source, target, and head deltas functions
+    """
+    rewards = [Gwei(0)] * len(state.validators)
+    penalties = [Gwei(0)] * len(state.validators)
+    total_balance = get_total_active_balance(state)
     unslashed_attesting_indices = get_unslashed_attesting_indices(state, attestations)
     attesting_balance = get_total_balance(state, unslashed_attesting_indices)
-        for index in eligible_validator_indices:
+    for index in get_eligible_validator_indices(state):
         if index in unslashed_attesting_indices:
             increment = EFFECTIVE_BALANCE_INCREMENT  # Factored out from balance totals to avoid uint64 overflow
             reward_numerator = get_base_reward(state, index) * (attesting_balance // increment)
             rewards[index] += reward_numerator // (total_balance // increment)
         else:
             penalties[index] += get_base_reward(state, index)
+    return rewards, penalties
+```
 
-    # Proposer and inclusion delay micro-rewards
+##### Components of attestation deltas
+
+```python
+def get_source_deltas(state: BeaconState) -> Tuple[Sequence[Gwei], Sequence[Gwei]]:
+    """
+    Return attester micro-rewards/penalties for source-vote for each validator.
+    """
+    matching_source_attestations = get_matching_source_attestations(state, get_previous_epoch(state))
+    return get_attestation_component_deltas(state, matching_source_attestations)
+```
+
+```python
+def get_target_deltas(state: BeaconState) -> Tuple[Sequence[Gwei], Sequence[Gwei]]:
+    """
+    Return attester micro-rewards/penalties for target-vote for each validator.
+    """
+    matching_target_attestations = get_matching_target_attestations(state, get_previous_epoch(state))
+    return get_attestation_component_deltas(state, matching_target_attestations)
+```
+
+```python
+def get_head_deltas(state: BeaconState) -> Tuple[Sequence[Gwei], Sequence[Gwei]]:
+    """
+    Return attester micro-rewards/penalties for head-vote for each validator.
+    """
+    matching_head_attestations = get_matching_head_attestations(state, get_previous_epoch(state))
+    return get_attestation_component_deltas(state, matching_head_attestations)
+```
+
+```python
+def get_inclusion_delay_deltas(state: BeaconState) -> Tuple[Sequence[Gwei], Sequence[Gwei]]:
+    """
+    Return proposer and inclusion delay micro-rewards/penalties for each validator.
+    """
+    rewards = [Gwei(0) for _ in range(len(state.validators))]
+    matching_source_attestations = get_matching_source_attestations(state, get_previous_epoch(state))
     for index in get_unslashed_attesting_indices(state, matching_source_attestations):
         attestation = min([
             a for a in matching_source_attestations
@@ -1385,19 +1431,61 @@ def get_attestation_deltas(state: BeaconState) -> Tuple[Sequence[Gwei], Sequence
         max_attester_reward = get_base_reward(state, index) - proposer_reward
         rewards[index] += Gwei(max_attester_reward // attestation.inclusion_delay)
 
-    # Inactivity penalty
+    # No penalties associated with inclusion delay
-    finality_delay = previous_epoch - state.finalized_checkpoint.epoch
+    penalties = [Gwei(0) for _ in range(len(state.validators))]
+    return rewards, penalties
+```
+
+```python
+def get_inactivity_penalty_deltas(state: BeaconState) -> Tuple[Sequence[Gwei], Sequence[Gwei]]:
+    """
+    Return inactivity reward/penalty deltas for each validator.
+    """
+    penalties = [Gwei(0) for _ in range(len(state.validators))]
+    finality_delay = get_previous_epoch(state) - state.finalized_checkpoint.epoch
+
     if finality_delay > MIN_EPOCHS_TO_INACTIVITY_PENALTY:
+        matching_target_attestations = get_matching_target_attestations(state, get_previous_epoch(state))
         matching_target_attesting_indices = get_unslashed_attesting_indices(state, matching_target_attestations)
-        for index in eligible_validator_indices:
+        for index in get_eligible_validator_indices(state):
             penalties[index] += Gwei(BASE_REWARDS_PER_EPOCH * get_base_reward(state, index))
             if index not in matching_target_attesting_indices:
                 effective_balance = state.validators[index].effective_balance
                 penalties[index] += Gwei(effective_balance * finality_delay // INACTIVITY_PENALTY_QUOTIENT)
 
+    # No rewards associated with inactivity penalties
+    rewards = [Gwei(0) for _ in range(len(state.validators))]
     return rewards, penalties
 ```
 
+##### `get_attestation_deltas`
+
+```python
+def get_attestation_deltas(state: BeaconState) -> Tuple[Sequence[Gwei], Sequence[Gwei]]:
+    """
+    Return attestation reward/penalty deltas for each validator.
+    """
+    source_rewards, source_penalties = get_source_deltas(state)
+    target_rewards, target_penalties = get_target_deltas(state)
+    head_rewards, head_penalties = get_head_deltas(state)
+    inclusion_delay_rewards, _ = get_inclusion_delay_deltas(state)
+    _, inactivity_penalties = get_inactivity_penalty_deltas(state)
+
+    rewards = [
+        source_rewards[i] + target_rewards[i] + head_rewards[i] + inclusion_delay_rewards[i]
+        for i in range(len(state.validators))
+    ]
+
+    penalties = [
+        source_penalties[i] + target_penalties[i] + head_penalties[i] + inactivity_penalties[i]
+        for i in range(len(state.validators))
+    ]
+
+    return rewards, penalties
+```
+
+##### `process_rewards_and_penalties`
+
 ```python
 def process_rewards_and_penalties(state: BeaconState) -> None:
     if get_current_epoch(state) == GENESIS_EPOCH:

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

@@ -1,7 +1,7 @@
 from typing import List
 
 from eth2spec.test.context import expect_assertion_error, PHASE0, PHASE1
-from eth2spec.test.helpers.state import state_transition_and_sign_block, next_slot, transition_to
+from eth2spec.test.helpers.state import state_transition_and_sign_block, next_epoch, next_slot, transition_to
 from eth2spec.test.helpers.block import build_empty_block_for_next_slot
 from eth2spec.test.helpers.keys import privkeys
 from eth2spec.utils import bls
@@ -323,6 +323,37 @@ def next_epoch_with_attestations(spec,
     return state, signed_blocks, post_state
 
 
+def prepare_state_with_full_attestations(spec, state, empty=False):
+    """
+    Fill ``state`` with maximally full attestations.
+    Move to the start of the next epoch to ensure full epoch worth.
+    """
+    # Go to start of next epoch to ensure can have full participation
+    next_epoch(spec, state)
+
+    start_slot = state.slot
+    start_epoch = spec.get_current_epoch(state)
+    next_epoch_start_slot = spec.compute_start_slot_at_epoch(start_epoch + 1)
+    attestations = []
+    for _ in range(spec.SLOTS_PER_EPOCH + spec.MIN_ATTESTATION_INCLUSION_DELAY):
+        # create an attestation for each index in each slot in epoch
+        if state.slot < next_epoch_start_slot:
+            for committee_index in range(spec.get_committee_count_at_slot(state, state.slot)):
+                attestation = get_valid_attestation(spec, state, index=committee_index, empty=empty, signed=True)
+                attestations.append(attestation)
+        # fill each created slot in state after inclusion delay
+        if state.slot >= start_slot + spec.MIN_ATTESTATION_INCLUSION_DELAY:
+            inclusion_slot = state.slot - spec.MIN_ATTESTATION_INCLUSION_DELAY
+            include_attestations = [att for att in attestations if att.data.slot == inclusion_slot]
+            add_attestations_to_state(spec, state, include_attestations, state.slot)
+        next_slot(spec, state)
+
+    assert state.slot == next_epoch_start_slot + spec.MIN_ATTESTATION_INCLUSION_DELAY
+    assert len(state.previous_epoch_attestations) == len(attestations)
+
+    return attestations
+
+
 def fill_block_shard_transitions_by_attestations(spec, state, block):
     block.body.shard_transitions = [spec.ShardTransition()] * spec.MAX_SHARDS
     for attestation in block.body.attestations:

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

@@ -0,0 +1,208 @@
+from random import Random
+
+from eth2spec.phase0 import spec as spec_phase0
+from eth2spec.test.helpers.attestations import prepare_state_with_full_attestations
+from eth2spec.test.helpers.state import next_epoch
+from eth2spec.utils.ssz.ssz_typing import Container, uint64, List
+
+
+class Deltas(Container):
+    rewards: List[uint64, spec_phase0.VALIDATOR_REGISTRY_LIMIT]
+    penalties: List[uint64, spec_phase0.VALIDATOR_REGISTRY_LIMIT]
+
+
+def has_enough_for_reward(spec, state, index):
+    """
+    Check if base_reward will be non-zero.
+
+    At very low balances, it is possible for a validator have a positive effective_balance
+    but a zero base reward.
+    """
+    return (
+        state.validators[index].effective_balance * spec.BASE_REWARD_FACTOR
+        > spec.integer_squareroot(spec.get_total_active_balance(state)) // spec.BASE_REWARDS_PER_EPOCH
+    )
+
+
+def run_attestation_component_deltas(spec, state, component_delta_fn, matching_att_fn):
+    """
+    Run ``component_delta_fn``, yielding:
+      - pre-state ('pre')
+      - deltas ('deltas')
+    """
+    yield 'pre', state
+
+    rewards, penalties = component_delta_fn(state)
+
+    yield 'deltas', Deltas(rewards=rewards, penalties=penalties)
+
+    matching_attestations = matching_att_fn(state, spec.get_previous_epoch(state))
+    matching_indices = spec.get_unslashed_attesting_indices(state, matching_attestations)
+    eligible_indices = spec.get_eligible_validator_indices(state)
+    for index in range(len(state.validators)):
+        if index not in eligible_indices:
+            assert rewards[index] == 0
+            assert penalties[index] == 0
+            continue
+
+        validator = state.validators[index]
+        enough_for_reward = has_enough_for_reward(spec, state, index)
+        if index in matching_indices and not validator.slashed:
+            if enough_for_reward:
+                assert rewards[index] > 0
+            else:
+                assert rewards[index] == 0
+            assert penalties[index] == 0
+        else:
+            assert rewards[index] == 0
+            if enough_for_reward:
+                assert penalties[index] > 0
+            else:
+                assert penalties[index] == 0
+
+
+def exit_random_validators(spec, state, rng):
+    if spec.get_current_epoch(state) < 5:
+        # Move epochs forward to allow for some validators already exited/withdrawable
+        for _ in range(5):
+            next_epoch(spec, state)
+
+    current_epoch = spec.get_current_epoch(state)
+    # Exit ~1/2 of validators
+    for validator in state.validators:
+        if rng.choice([True, False]):
+            continue
+
+        validator.exit_epoch = rng.choice([current_epoch - 1, current_epoch - 2, current_epoch - 3])
+        # ~1/2 are withdrawable
+        if rng.choice([True, False]):
+            validator.withdrawable_epoch = current_epoch
+        else:
+            validator.withdrawable_epoch = current_epoch + 1
+
+
+def slash_random_validators(spec, state, rng):
+    # Slash ~1/2 of validators
+    for validator in state.validators:
+        validator.slashed = rng.choice([True, False])
+
+
+def run_test_empty(spec, state, runner):
+    # Do not add any attestations to state
+
+    yield from runner(spec, state)
+
+
+def run_test_full_all_correct(spec, state, runner):
+    prepare_state_with_full_attestations(spec, state)
+
+    yield from runner(spec, state)
+
+
+def run_test_full_but_partial_participation(spec, state, runner, rng=Random(5522)):
+    prepare_state_with_full_attestations(spec, state)
+
+    for a in state.previous_epoch_attestations:
+        a.aggregation_bits = [rng.choice([True, False]) for _ in a.aggregation_bits]
+
+    yield from runner(spec, state)
+
+
+def run_test_partial(spec, state, fraction_filled, runner):
+    prepare_state_with_full_attestations(spec, state)
+
+    # Remove portion of attestations
+    num_attestations = int(len(state.previous_epoch_attestations) * fraction_filled)
+    state.previous_epoch_attestations = state.previous_epoch_attestations[:num_attestations]
+
+    yield from runner(spec, state)
+
+
+def run_test_half_full(spec, state, runner):
+    yield from run_test_partial(spec, state, 0.5, runner)
+
+
+def run_test_one_attestation_one_correct(spec, state, runner):
+    prepare_state_with_full_attestations(spec, state)
+
+    # Remove all attestations except for the first one
+    state.previous_epoch_attestations = state.previous_epoch_attestations[:1]
+
+    yield from runner(spec, state)
+
+
+def run_test_with_exited_validators(spec, state, runner, rng=Random(1337)):
+    exit_random_validators(spec, state, rng)
+    prepare_state_with_full_attestations(spec, state)
+
+    yield from runner(spec, state)
+
+
+def run_test_with_slashed_validators(spec, state, runner, rng=Random(3322)):
+    exit_random_validators(spec, state, rng)
+    slash_random_validators(spec, state, rng)
+
+    prepare_state_with_full_attestations(spec, state)
+
+    yield from runner(spec, state)
+
+
+def run_test_some_very_low_effective_balances_that_attested(spec, state, runner):
+    state.balances
+    prepare_state_with_full_attestations(spec, state)
+
+    # Set some balances to be very low (including 0)
+    assert len(state.validators) >= 5
+    for i, index in enumerate(range(5)):
+        state.validators[index].effective_balance = i
+
+    yield from runner(spec, state)
+
+
+def run_test_some_very_low_effective_balances_that_did_not_attest(spec, state, runner):
+    prepare_state_with_full_attestations(spec, state)
+
+    # Remove attestation
+    attestation = state.previous_epoch_attestations[0]
+    state.previous_epoch_attestations = state.previous_epoch_attestations[1:]
+    # Set removed indices effective balance to very low amount
+    indices = spec.get_unslashed_attesting_indices(state, [attestation])
+    for i, index in enumerate(indices):
+        state.validators[index].effective_balance = i
+
+    yield from runner(spec, state)
+
+
+def run_test_full_fraction_incorrect(spec, state, correct_target, correct_head, fraction_incorrect, runner):
+    prepare_state_with_full_attestations(spec, state)
+
+    # Make fraction_incorrect of pending attestations have bad target/head as specified
+    num_incorrect = int(fraction_incorrect * len(state.previous_epoch_attestations))
+    for pending_attestation in state.previous_epoch_attestations[:num_incorrect]:
+        if not correct_target:
+            pending_attestation.data.target.root = b'\x55' * 32
+        if not correct_head:
+            pending_attestation.data.beacon_block_root = b'\x66' * 32
+
+    yield from runner(spec, state)
+
+
+def run_test_full_random(spec, state, runner, rng=Random(8020)):
+    exit_random_validators(spec, state, rng)
+    slash_random_validators(spec, state, rng)
+
+    prepare_state_with_full_attestations(spec, state)
+
+    for pending_attestation in state.previous_epoch_attestations:
+        # ~1/3 have bad target
+        if rng.randint(0, 2) == 0:
+            pending_attestation.data.target.root = b'\x55' * 32
+        # ~1/3 have bad head
+        if rng.randint(0, 2) == 0:
+            pending_attestation.data.beacon_block_root = b'\x66' * 32
+        # ~50% participation
+        pending_attestation.aggregation_bits = [rng.choice([True, False]) for _ in pending_attestation.aggregation_bits]
+        # Random inclusion delay
+        pending_attestation.inclusion_delay = rng.randint(1, spec.SLOTS_PER_EPOCH)
+
+    yield from runner(spec, state)

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

@@ -12,6 +12,7 @@ from eth2spec.test.helpers.state import (
 from eth2spec.test.helpers.attestations import (
     add_attestations_to_state,
     get_valid_attestation,
+    prepare_state_with_full_attestations,
 )
 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
@@ -21,33 +22,6 @@ def run_process_rewards_and_penalties(spec, state):
     yield from run_epoch_processing_with(spec, state, 'process_rewards_and_penalties')
 
 
-def prepare_state_with_full_attestations(spec, state, empty=False):
-    # Go to start of next epoch to ensure can have full participation
-    next_epoch(spec, state)
-
-    start_slot = state.slot
-    start_epoch = spec.get_current_epoch(state)
-    next_epoch_start_slot = spec.compute_start_slot_at_epoch(start_epoch + 1)
-    attestations = []
-    for _ in range(spec.SLOTS_PER_EPOCH + spec.MIN_ATTESTATION_INCLUSION_DELAY):
-        # create an attestation for each index in each slot in epoch
-        if state.slot < next_epoch_start_slot:
-            for committee_index in range(spec.get_committee_count_at_slot(state, state.slot)):
-                attestation = get_valid_attestation(spec, state, index=committee_index, empty=empty, signed=True)
-                attestations.append(attestation)
-        # fill each created slot in state after inclusion delay
-        if state.slot >= start_slot + spec.MIN_ATTESTATION_INCLUSION_DELAY:
-            inclusion_slot = state.slot - spec.MIN_ATTESTATION_INCLUSION_DELAY
-            include_attestations = [att for att in attestations if att.data.slot == inclusion_slot]
-            add_attestations_to_state(spec, state, include_attestations, state.slot)
-        next_slot(spec, state)
-
-    assert state.slot == next_epoch_start_slot + spec.MIN_ATTESTATION_INCLUSION_DELAY
-    assert len(state.previous_epoch_attestations) == len(attestations)
-
-    return attestations
-
-
 @with_phases(['phase0'])
 @spec_state_test
 def test_genesis_epoch_no_attestations_no_penalties(spec, state):

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

@@ -0,0 +1,130 @@
+from eth2spec.test.context import with_all_phases, spec_state_test
+from eth2spec.test.helpers.rewards import run_attestation_component_deltas
+import eth2spec.test.helpers.rewards as rewards_helpers
+
+
+def run_get_head_deltas(spec, state):
+    """
+    Run ``get_head_deltas``, yielding:
+      - pre-state ('pre')
+      - deltas ('deltas')
+    """
+
+    yield from run_attestation_component_deltas(
+        spec,
+        state,
+        spec.get_head_deltas,
+        spec.get_matching_head_attestations,
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_empty(spec, state):
+    yield from rewards_helpers.run_test_empty(spec, state, run_get_head_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_all_correct(spec, state):
+    yield from rewards_helpers.run_test_full_all_correct(spec, state, run_get_head_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_half_full(spec, state):
+    yield from rewards_helpers.run_test_half_full(spec, state, run_get_head_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_but_partial_participation(spec, state):
+    yield from rewards_helpers.run_test_full_but_partial_participation(spec, state, run_get_head_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_one_attestation_one_correct(spec, state):
+    yield from rewards_helpers.run_test_one_attestation_one_correct(spec, state, run_get_head_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_with_exited_validators(spec, state):
+    yield from rewards_helpers.run_test_with_exited_validators(spec, state, run_get_head_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_with_slashed_validators(spec, state):
+    yield from rewards_helpers.run_test_with_slashed_validators(spec, state, run_get_head_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_some_very_low_effective_balances_that_attested(spec, state):
+    yield from rewards_helpers.run_test_some_very_low_effective_balances_that_attested(spec, state, run_get_head_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_some_very_low_effective_balances_that_did_not_attest(spec, state):
+    yield from rewards_helpers.run_test_some_very_low_effective_balances_that_did_not_attest(
+        spec,
+        state,
+        run_get_head_deltas,
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_full_half_correct_target_incorrect_head(spec, state):
+    yield from rewards_helpers.run_test_full_fraction_incorrect(
+        spec, state,
+        correct_target=True,
+        correct_head=False,
+        fraction_incorrect=0.5,
+        runner=run_get_head_deltas
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_full_correct_target_incorrect_head(spec, state):
+    yield from rewards_helpers.run_test_full_fraction_incorrect(
+        spec, state,
+        correct_target=True,
+        correct_head=False,
+        fraction_incorrect=1.0,
+        runner=run_get_head_deltas
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_full_half_incorrect_target_incorrect_head(spec, state):
+    yield from rewards_helpers.run_test_full_fraction_incorrect(
+        spec, state,
+        correct_target=False,
+        correct_head=False,
+        fraction_incorrect=0.5,
+        runner=run_get_head_deltas
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_full_half_incorrect_target_correct_head(spec, state):
+    yield from rewards_helpers.run_test_full_fraction_incorrect(
+        spec, state,
+        correct_target=False,
+        correct_head=True,
+        fraction_incorrect=0.5,
+        runner=run_get_head_deltas
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_full_random(spec, state):
+    yield from rewards_helpers.run_test_full_random(spec, state, run_get_head_deltas)

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

@@ -0,0 +1,210 @@
+from eth2spec.test.context import with_all_phases, spec_state_test
+from eth2spec.test.helpers.rewards import has_enough_for_reward
+from eth2spec.test.helpers.state import next_epoch
+from eth2spec.test.helpers.rewards import Deltas
+import eth2spec.test.helpers.rewards as rewards_helpers
+
+
+def run_get_inactivity_penalty_deltas(spec, state):
+    """
+    Run ``get_inactivity_penalty_deltas``, yielding:
+      - pre-state ('pre')
+      - deltas ('deltas')
+    """
+
+    yield 'pre', state
+
+    rewards, penalties = spec.get_inactivity_penalty_deltas(state)
+
+    yield 'deltas', Deltas(rewards=rewards, penalties=penalties)
+
+    matching_attestations = spec.get_matching_target_attestations(state, spec.get_previous_epoch(state))
+    matching_attesting_indices = spec.get_unslashed_attesting_indices(state, matching_attestations)
+
+    finality_delay = spec.get_previous_epoch(state) - state.finalized_checkpoint.epoch
+    eligible_indices = spec.get_eligible_validator_indices(state)
+    for index in range(len(state.validators)):
+        assert rewards[index] == 0
+        if index not in eligible_indices:
+            assert penalties[index] == 0
+            continue
+
+        if finality_delay > spec.MIN_EPOCHS_TO_INACTIVITY_PENALTY:
+            base_penalty = spec.BASE_REWARDS_PER_EPOCH * spec.get_base_reward(state, index)
+            if not has_enough_for_reward(spec, state, index):
+                assert penalties[index] == 0
+            elif index in matching_attesting_indices:
+                assert penalties[index] == base_penalty
+            else:
+                assert penalties[index] > base_penalty
+        else:
+            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)
+
+
+@with_all_phases
+@spec_state_test
+def test_empty_no_leak(spec, state):
+    yield from rewards_helpers.run_test_empty(spec, state, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_empty_leak(spec, state):
+    transition_state_to_leak(spec, state)
+    yield from rewards_helpers.run_test_empty(spec, state, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_no_leak(spec, state):
+    yield from rewards_helpers.run_test_full_all_correct(spec, state, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_leak(spec, state):
+    transition_state_to_leak(spec, state)
+    yield from rewards_helpers.run_test_full_all_correct(spec, state, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_half_full_no_leak(spec, state):
+    yield from rewards_helpers.run_test_half_full(spec, state, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_half_full_leak(spec, state):
+    transition_state_to_leak(spec, state)
+    yield from rewards_helpers.run_test_half_full(spec, state, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_quarter_full_no_leak(spec, state):
+    yield from rewards_helpers.run_test_partial(spec, state, 0.25, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_quarter_full_leak(spec, state):
+    transition_state_to_leak(spec, state)
+    yield from rewards_helpers.run_test_partial(spec, state, 0.25, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_but_partial_participation_no_leak(spec, state):
+    yield from rewards_helpers.run_test_full_but_partial_participation(spec, state, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_but_partial_participation_leak(spec, state):
+    transition_state_to_leak(spec, state)
+    yield from rewards_helpers.run_test_full_but_partial_participation(spec, state, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_with_exited_validators_no_leak(spec, state):
+    yield from rewards_helpers.run_test_with_exited_validators(spec, state, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_with_exited_validators_leak(spec, state):
+    transition_state_to_leak(spec, state)
+    yield from rewards_helpers.run_test_with_exited_validators(spec, state, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_with_slashed_validators_no_leak(spec, state):
+    yield from rewards_helpers.run_test_with_slashed_validators(spec, state, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_with_slashed_validators_leak(spec, state):
+    transition_state_to_leak(spec, state)
+    yield from rewards_helpers.run_test_with_slashed_validators(spec, state, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_some_very_low_effective_balances_that_attested_no_leak(spec, state):
+    yield from rewards_helpers.run_test_some_very_low_effective_balances_that_attested(
+        spec,
+        state,
+        run_get_inactivity_penalty_deltas,
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_some_very_low_effective_balances_that_attested_leak(spec, state):
+    transition_state_to_leak(spec, state)
+    yield from rewards_helpers.run_test_some_very_low_effective_balances_that_attested(
+        spec,
+        state,
+        run_get_inactivity_penalty_deltas,
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_some_very_low_effective_balances_that_did_not_attest_no_leak(spec, state):
+    yield from rewards_helpers.run_test_some_very_low_effective_balances_that_did_not_attest(
+        spec,
+        state,
+        run_get_inactivity_penalty_deltas,
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_some_very_low_effective_balances_that_did_not_attest_leak(spec, state):
+    transition_state_to_leak(spec, state)
+    yield from rewards_helpers.run_test_some_very_low_effective_balances_that_did_not_attest(
+        spec,
+        state,
+        run_get_inactivity_penalty_deltas,
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_full_random_no_leak(spec, state):
+    yield from rewards_helpers.run_test_full_random(spec, state, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_random_leak(spec, state):
+    transition_state_to_leak(spec, state)
+    yield from rewards_helpers.run_test_full_random(spec, state, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_random_five_epoch_leak(spec, state):
+    transition_state_to_leak(spec, state, epochs=5)
+    yield from rewards_helpers.run_test_full_random(spec, state, run_get_inactivity_penalty_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_random_ten_epoch_leak(spec, state):
+    transition_state_to_leak(spec, state, epochs=10)
+    yield from rewards_helpers.run_test_full_random(spec, state, run_get_inactivity_penalty_deltas)

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

@@ -0,0 +1,207 @@
+from random import Random
+
+from eth2spec.test.context import with_all_phases, spec_state_test
+from eth2spec.test.helpers.attestations import prepare_state_with_full_attestations
+from eth2spec.test.helpers.rewards import Deltas, has_enough_for_reward
+import eth2spec.test.helpers.rewards as rewards_helpers
+
+
+def run_get_inclusion_delay_deltas(spec, state):
+    """
+    Run ``get_inclusion_delay_deltas``, yielding:
+      - pre-state ('pre')
+      - deltas ('deltas')
+    """
+
+    yield 'pre', state
+
+    rewards, penalties = spec.get_inclusion_delay_deltas(state)
+
+    yield 'deltas', Deltas(rewards=rewards, penalties=penalties)
+
+    eligible_attestations = spec.get_matching_source_attestations(state, spec.get_previous_epoch(state))
+    attesting_indices = spec.get_unslashed_attesting_indices(state, eligible_attestations)
+
+    rewarded_indices = set()
+    rewarded_proposer_indices = set()
+    # Ensure attesters with enough balance are rewarded for attestations
+    # Track those that are rewarded and track proposers that should be rewarded
+    for index in range(len(state.validators)):
+        if index in attesting_indices and has_enough_for_reward(spec, state, index):
+            assert rewards[index] > 0
+            rewarded_indices.add(index)
+
+            # Track proposer of earliest included attestation for the validator defined by index
+            earliest_attestation = min([
+                a for a in eligible_attestations
+                if index in spec.get_attesting_indices(state, a.data, a.aggregation_bits)
+            ], key=lambda a: a.inclusion_delay)
+            rewarded_proposer_indices.add(earliest_attestation.proposer_index)
+
+    # Ensure all expected proposers have been rewarded
+    # Track rewarde indices
+    proposing_indices = [a.proposer_index for a in eligible_attestations]
+    for index in proposing_indices:
+        if index in rewarded_proposer_indices:
+            assert rewards[index] > 0
+            rewarded_indices.add(index)
+
+    # Ensure all expected non-rewarded indices received no reward
+    for index in range(len(state.validators)):
+        assert penalties[index] == 0
+        if index not in rewarded_indices:
+            assert rewards[index] == 0
+
+
+@with_all_phases
+@spec_state_test
+def test_empty(spec, state):
+    yield from rewards_helpers.run_test_empty(spec, state, run_get_inclusion_delay_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_full(spec, state):
+    yield from rewards_helpers.run_test_full_all_correct(spec, state, run_get_inclusion_delay_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_half_full(spec, state):
+    yield from rewards_helpers.run_test_half_full(spec, state, run_get_inclusion_delay_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_quarter_full(spec, state):
+    yield from rewards_helpers.run_test_partial(spec, state, 0.25, run_get_inclusion_delay_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_but_partial_participation(spec, state):
+    yield from rewards_helpers.run_test_full_but_partial_participation(spec, state, run_get_inclusion_delay_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_with_exited_validators(spec, state):
+    yield from rewards_helpers.run_test_with_exited_validators(spec, state, run_get_inclusion_delay_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_with_slashed_validators(spec, state):
+    yield from rewards_helpers.run_test_with_slashed_validators(spec, state, run_get_inclusion_delay_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_some_very_low_effective_balances_that_attested(spec, state):
+    yield from rewards_helpers.run_test_some_very_low_effective_balances_that_attested(
+        spec,
+        state,
+        run_get_inclusion_delay_deltas
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_full_random(spec, state):
+    yield from rewards_helpers.run_test_full_random(spec, state, run_get_inclusion_delay_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_delay_one_slot(spec, state):
+    prepare_state_with_full_attestations(spec, state)
+    for a in state.previous_epoch_attestations:
+        a.inclusion_delay += 1
+
+    yield from run_get_inclusion_delay_deltas(spec, state)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_delay_max_slots(spec, state):
+    prepare_state_with_full_attestations(spec, state)
+    for a in state.previous_epoch_attestations:
+        a.inclusion_delay += spec.SLOTS_PER_EPOCH
+
+    yield from run_get_inclusion_delay_deltas(spec, state)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_mixed_delay(spec, state):
+    rng = Random(1234)
+
+    prepare_state_with_full_attestations(spec, state)
+    for a in state.previous_epoch_attestations:
+        a.inclusion_delay = rng.randint(1, spec.SLOTS_PER_EPOCH)
+
+    yield from run_get_inclusion_delay_deltas(spec, state)
+
+
+@with_all_phases
+@spec_state_test
+def test_proposer_not_in_attestations(spec, state):
+    prepare_state_with_full_attestations(spec, state)
+
+    # Get an attestation where the proposer is not in the committee
+    non_proposer_attestations = []
+    for a in state.previous_epoch_attestations:
+        if a.proposer_index not in spec.get_unslashed_attesting_indices(state, [a]):
+            non_proposer_attestations.append(a)
+
+    assert any(non_proposer_attestations)
+    state.previous_epoch_attestations = non_proposer_attestations
+
+    yield from run_get_inclusion_delay_deltas(spec, state)
+
+
+@with_all_phases
+@spec_state_test
+def test_duplicate_attestations_at_later_slots(spec, state):
+    prepare_state_with_full_attestations(spec, state)
+
+    # Remove 2/3 of attestations to make it more interesting
+    num_attestations = int(len(state.previous_epoch_attestations) * 0.33)
+    state.previous_epoch_attestations = state.previous_epoch_attestations[:num_attestations]
+
+    # Get map of the proposer at each slot to make valid-looking duplicate attestations
+    per_slot_proposers = {
+        (a.data.slot + a.inclusion_delay): a.proposer_index
+        for a in state.previous_epoch_attestations
+    }
+    max_slot = max([a.data.slot + a.inclusion_delay for a in state.previous_epoch_attestations])
+    later_attestations = []
+    for a in state.previous_epoch_attestations:
+        # Only have proposers for previous epoch so do not create later
+        # duplicate if slot exceeds the max slot in previous_epoch_attestations
+        if a.data.slot + a.inclusion_delay >= max_slot:
+            continue
+        later_a = a.copy()
+        later_a.inclusion_delay += 1
+        later_a.proposer_index = per_slot_proposers[later_a.data.slot + later_a.inclusion_delay]
+        later_attestations.append(later_a)
+
+    assert any(later_attestations)
+
+    state.previous_epoch_attestations = sorted(
+        state.previous_epoch_attestations + later_attestations,
+        key=lambda a: a.data.slot + a.inclusion_delay
+    )
+
+    yield from run_get_inclusion_delay_deltas(spec, state)
+
+
+@with_all_phases
+@spec_state_test
+def test_all_balances_too_low_for_reward(spec, state):
+    prepare_state_with_full_attestations(spec, state)
+
+    for index in range(len(state.validators)):
+        state.validators[index].effective_balance = 10
+
+    yield from run_get_inclusion_delay_deltas(spec, state)

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

@@ -0,0 +1,141 @@
+from eth2spec.test.context import with_all_phases, spec_state_test
+from eth2spec.test.helpers.rewards import run_attestation_component_deltas
+import eth2spec.test.helpers.rewards as rewards_helpers
+
+
+def run_get_source_deltas(spec, state):
+    """
+    Run ``get_source_deltas``, yielding:
+      - pre-state ('pre')
+      - deltas ('deltas')
+    """
+
+    yield from run_attestation_component_deltas(
+        spec,
+        state,
+        spec.get_source_deltas,
+        spec.get_matching_source_attestations,
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_empty(spec, state):
+    yield from rewards_helpers.run_test_empty(spec, state, run_get_source_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_all_correct(spec, state):
+    yield from rewards_helpers.run_test_full_all_correct(spec, state, run_get_source_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_half_full(spec, state):
+    yield from rewards_helpers.run_test_half_full(spec, state, run_get_source_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_but_partial_participation(spec, state):
+    yield from rewards_helpers.run_test_full_but_partial_participation(spec, state, run_get_source_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_one_attestation_one_correct(spec, state):
+    yield from rewards_helpers.run_test_one_attestation_one_correct(spec, state, run_get_source_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_with_exited_validators(spec, state):
+    yield from rewards_helpers.run_test_with_exited_validators(spec, state, run_get_source_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_with_slashed_validators(spec, state):
+    yield from rewards_helpers.run_test_with_slashed_validators(spec, state, run_get_source_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_some_very_low_effective_balances_that_attested(spec, state):
+    yield from rewards_helpers.run_test_some_very_low_effective_balances_that_attested(
+        spec,
+        state,
+        run_get_source_deltas
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_some_very_low_effective_balances_that_did_not_attest(spec, state):
+    yield from rewards_helpers.run_test_some_very_low_effective_balances_that_did_not_attest(
+        spec,
+        state,
+        run_get_source_deltas,
+    )
+
+
+#
+# NOTE: No source incorrect tests
+# All PendingAttestations in state have source validated
+# We choose to keep this invariant in these tests to not force clients to test with degenerate states
+#
+
+
+@with_all_phases
+@spec_state_test
+def test_full_half_correct_target_incorrect_head(spec, state):
+    yield from rewards_helpers.run_test_full_fraction_incorrect(
+        spec, state,
+        correct_target=True,
+        correct_head=False,
+        fraction_incorrect=0.5,
+        runner=run_get_source_deltas
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_full_correct_target_incorrect_head(spec, state):
+    yield from rewards_helpers.run_test_full_fraction_incorrect(
+        spec, state,
+        correct_target=True,
+        correct_head=False,
+        fraction_incorrect=1.0,
+        runner=run_get_source_deltas
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_full_half_incorrect_target_incorrect_head(spec, state):
+    yield from rewards_helpers.run_test_full_fraction_incorrect(
+        spec, state,
+        correct_target=False,
+        correct_head=False,
+        fraction_incorrect=0.5,
+        runner=run_get_source_deltas
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_full_half_incorrect_target_correct_head(spec, state):
+    yield from rewards_helpers.run_test_full_fraction_incorrect(
+        spec, state,
+        correct_target=False,
+        correct_head=True,
+        fraction_incorrect=0.5,
+        runner=run_get_source_deltas
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_full_random(spec, state):
+    yield from rewards_helpers.run_test_full_random(spec, state, run_get_source_deltas)

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

@@ -0,0 +1,128 @@
+from eth2spec.test.context import with_all_phases, spec_state_test
+from eth2spec.test.helpers.rewards import run_attestation_component_deltas
+import eth2spec.test.helpers.rewards as rewards_helpers
+
+
+def run_get_target_deltas(spec, state):
+    """
+    Run ``get_target_deltas``, yielding:
+      - pre-state ('pre')
+      - deltas ('deltas')
+    """
+
+    yield from run_attestation_component_deltas(
+        spec,
+        state,
+        spec.get_target_deltas,
+        spec.get_matching_target_attestations,
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_empty(spec, state):
+    yield from rewards_helpers.run_test_empty(spec, state, run_get_target_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_all_correct(spec, state):
+    yield from rewards_helpers.run_test_full_all_correct(spec, state, run_get_target_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_half_full(spec, state):
+    yield from rewards_helpers.run_test_half_full(spec, state, run_get_target_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_full_but_partial_participation(spec, state):
+    yield from rewards_helpers.run_test_full_but_partial_participation(spec, state, run_get_target_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_one_attestation_one_correct(spec, state):
+    yield from rewards_helpers.run_test_one_attestation_one_correct(spec, state, run_get_target_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_with_slashed_validators(spec, state):
+    yield from rewards_helpers.run_test_with_slashed_validators(spec, state, run_get_target_deltas)
+
+
+@with_all_phases
+@spec_state_test
+def test_some_very_low_effective_balances_that_attested(spec, state):
+    yield from rewards_helpers.run_test_some_very_low_effective_balances_that_attested(
+        spec,
+        state,
+        run_get_target_deltas
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_some_very_low_effective_balances_that_did_not_attest(spec, state):
+    yield from rewards_helpers.run_test_some_very_low_effective_balances_that_did_not_attest(
+        spec,
+        state,
+        run_get_target_deltas,
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_full_half_correct_target_incorrect_head(spec, state):
+    yield from rewards_helpers.run_test_full_fraction_incorrect(
+        spec, state,
+        correct_target=True,
+        correct_head=False,
+        fraction_incorrect=0.5,
+        runner=run_get_target_deltas
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_full_correct_target_incorrect_head(spec, state):
+    yield from rewards_helpers.run_test_full_fraction_incorrect(
+        spec, state,
+        correct_target=True,
+        correct_head=False,
+        fraction_incorrect=1.0,
+        runner=run_get_target_deltas
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_full_half_incorrect_target_incorrect_head(spec, state):
+    yield from rewards_helpers.run_test_full_fraction_incorrect(
+        spec, state,
+        correct_target=False,
+        correct_head=False,
+        fraction_incorrect=0.5,
+        runner=run_get_target_deltas
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_full_half_incorrect_target_correct_head(spec, state):
+    yield from rewards_helpers.run_test_full_fraction_incorrect(
+        spec, state,
+        correct_target=False,
+        correct_head=True,
+        fraction_incorrect=0.5,
+        runner=run_get_target_deltas
+    )
+
+
+@with_all_phases
+@spec_state_test
+def test_full_random(spec, state):
+    yield from rewards_helpers.run_test_full_random(spec, state, run_get_target_deltas)

tests/formats/rewards/README.md

@@ -0,0 +1,52 @@
+# Rewards tests
+
+The different rewards deltas sub-functions are testing individually with the test handlers, each returning the related `rewards`/`penalties`.
+There is no "change" factor, the rewards/penalties outputs are pure functions with just the pre-state as input.
+Hence, the format is shared between each test-handler. (See test condition documentation on how to run the tests.)
+
+## Test case format
+
+### `meta.yaml`
+
+```yaml
+description: string    -- Optional description of test case, purely for debugging purposes.
+                          Tests should use the directory name of the test case as identifier, not the description.
+```
+
+_Note_: No signature verification happens within rewards sub-functions. These
+ tests can safely be run with or without BLS enabled.
+
+### `pre.yaml`
+
+A YAML-encoded `BeaconState`, the state before running the rewards sub-function.
+
+Also available as `pre.ssz`.
+
+### `deltas.yaml`
+
+A YAML-encoded `Deltas` representing the rewards and penalties returned by the rewards sub-function
+
+Where `Deltas` is defined as:
+```python
+class Deltas(Container):
+    rewards: List[uint64, VALIDATOR_REGISTRY_LIMIT]
+    penalties: List[uint64, VALIDATOR_REGISTRY_LIMIT]
+```
+
+Also available as `deltas.ssz`.
+
+## Condition
+
+A handler of the `rewards` test-runner should process these cases, 
+ calling the corresponding rewards deltas function (same name in spec).
+This excludes all other parts of `process_rewards_and_penalties`
+
+The provided pre-state is ready to be input into the designated handler.
+
+The provided `deltas` should match the return values of the
+ handler. Specifically the following must hold true:
+
+```python
+    deltas.rewards == handler(state)[0]
+    deltas.penalties == handler(state)[1]
+```

tests/generators/rewards/README.md

@@ -0,0 +1,8 @@
+# Rewards
+
+Rewards covers the sub-functions of `process_rewards_and_penalties` for granular testing of components of the rewards function.
+
+A rewards test-runner can consume these sub-transition test-suites,
+ and handle different kinds of epoch sub-transitions by processing the cases using the specified test handler.
+
+Information on the format of the tests can be found in the [rewards test formats documentation](../../formats/rewards/README.md).

tests/generators/rewards/main.py

@@ -0,0 +1,50 @@
+from typing import Iterable
+
+from eth2spec.phase0 import spec as spec_phase0
+from eth2spec.phase1 import spec as spec_phase1
+from eth2spec.test.phase_0.rewards import (
+    test_get_source_deltas,
+    test_get_target_deltas,
+    test_get_head_deltas,
+    test_get_inclusion_delay_deltas,
+    test_get_inactivity_penalty_deltas,
+)
+from gen_base import gen_runner, gen_typing
+from gen_from_tests.gen import generate_from_tests
+from importlib import reload
+from eth2spec.config import config_util
+from eth2spec.test.context import PHASE0
+
+
+def create_provider(handler_name: str, tests_src, config_name: str) -> gen_typing.TestProvider:
+
+    def prepare_fn(configs_path: str) -> str:
+        config_util.prepare_config(configs_path, config_name)
+        reload(spec_phase0)
+        reload(spec_phase1)
+        return config_name
+
+    def cases_fn() -> Iterable[gen_typing.TestCase]:
+        return generate_from_tests(
+            runner_name='rewards',
+            handler_name=handler_name,
+            src=tests_src,
+            fork_name=PHASE0,
+        )
+
+    return gen_typing.TestProvider(prepare=prepare_fn, make_cases=cases_fn)
+
+
+if __name__ == "__main__":
+    gen_runner.run_generator("epoch_processing", [
+        create_provider('get_source_deltas', test_get_source_deltas, 'minimal'),
+        create_provider('get_source_deltas', test_get_source_deltas, 'mainnet'),
+        create_provider('get_target_deltas', test_get_target_deltas, 'minimal'),
+        create_provider('get_target_deltas', test_get_target_deltas, 'mainnet'),
+        create_provider('get_head_deltas', test_get_head_deltas, 'minimal'),
+        create_provider('get_head_deltas', test_get_head_deltas, 'mainnet'),
+        create_provider('get_inclusion_delay_deltas', test_get_inclusion_delay_deltas, 'minimal'),
+        create_provider('get_inclusion_delay_deltas', test_get_inclusion_delay_deltas, 'mainnet'),
+        create_provider('get_inactivity_penalty_deltas', test_get_inactivity_penalty_deltas, 'minimal'),
+        create_provider('get_inactivity_penalty_deltas', test_get_inactivity_penalty_deltas, 'mainnet'),
+    ])

tests/generators/rewards/requirements.txt

@@ -0,0 +1,2 @@
+../../core/gen_helpers
+../../../