From cc04da8e795ca9d8774f033434765e5be2edafe6 Mon Sep 17 00:00:00 2001
From: Alex Stokes <r.alex.stokes@gmail.com>
Date: Mon, 23 Aug 2021 12:30:05 -0700
Subject: [PATCH] add randomized block tests for altair

---
 .../test/altair/sanity/test_blocks_random.py  | 63 +++++++++++++++++++
 .../eth2spec/test/helpers/multi_operations.py | 20 ++++++
 .../core/pyspec/eth2spec/test/utils/random.py |  4 +-
 tests/generators/sanity/main.py               |  1 +
 4 files changed, 86 insertions(+), 2 deletions(-)
 create mode 100644 tests/core/pyspec/eth2spec/test/altair/sanity/test_blocks_random.py

diff --git a/tests/core/pyspec/eth2spec/test/altair/sanity/test_blocks_random.py b/tests/core/pyspec/eth2spec/test/altair/sanity/test_blocks_random.py
new file mode 100644
index 000000000..b0c0e86b5
--- /dev/null
+++ b/tests/core/pyspec/eth2spec/test/altair/sanity/test_blocks_random.py
@@ -0,0 +1,63 @@
+from tests.core.pyspec.eth2spec.test.helpers.constants import ALTAIR
+from tests.core.pyspec.eth2spec.test.context import (
+    misc_balances_in_default_range_with_many_validators,
+    with_phases,
+    zero_activation_threshold,
+)
+from eth2spec.test.helpers.multi_operations import (
+    get_random_sync_aggregate,
+)
+from eth2spec.test.helpers.inactivity_scores import (
+    randomize_inactivity_scores,
+)
+from eth2spec.test.context import (
+    always_bls,
+    spec_test,
+    with_custom_state,
+    single_phase,
+)
+from eth2spec.test.utils.random import (
+    generate_randomized_tests,
+    pytest_generate_tests_adapter,
+    run_generated_randomized_test,
+    random_block,
+    randomize_state,
+)
+
+SYNC_AGGREGATE_PARTICIPATION_BUCKETS = 4
+
+def _randomize_altair_state(spec, state):
+    randomize_state(spec, state, exit_fraction=0.1, slash_fraction=0.1)
+    randomize_inactivity_scores(spec, state)
+
+
+def _randomize_altair_block(spec, state, signed_blocks):
+    block = random_block(spec, state, signed_blocks)
+    fraction_missed = len(signed_blocks) / SYNC_AGGREGATE_PARTICIPATION_BUCKETS
+    fraction_participated = 1.0 - fraction_missed
+    block.body.sync_aggregate = get_random_sync_aggregate(spec, state, fraction_participated=fraction_participated)
+    return block
+
+
+def pytest_generate_tests(metafunc):
+    """
+    Pytest hook to generate test cases from dynamically computed data
+    """
+    generate_randomized_tests(
+        metafunc,
+        state_randomizer=_randomize_altair_state,
+        block_randomizer=_randomize_altair_block,
+    )
+
+
+@pytest_generate_tests_adapter
+@with_phases([ALTAIR])
+@with_custom_state(
+    balances_fn=misc_balances_in_default_range_with_many_validators,
+    threshold_fn=zero_activation_threshold
+)
+@spec_test
+@single_phase
+@always_bls
+def test_harness_for_randomized_blocks(spec, state, test_description):
+    yield from run_generated_randomized_test(spec, state, test_description)
diff --git a/tests/core/pyspec/eth2spec/test/helpers/multi_operations.py b/tests/core/pyspec/eth2spec/test/helpers/multi_operations.py
index 68ca02b91..10de14253 100644
--- a/tests/core/pyspec/eth2spec/test/helpers/multi_operations.py
+++ b/tests/core/pyspec/eth2spec/test/helpers/multi_operations.py
@@ -7,6 +7,10 @@ from eth2spec.test.helpers.state import (
 from eth2spec.test.helpers.block import (
     build_empty_block_for_next_slot,
 )
+from eth2spec.test.helpers.sync_committee import (
+    compute_committee_indices,
+    compute_aggregate_sync_committee_signature,
+)
 from eth2spec.test.helpers.proposer_slashings import get_valid_proposer_slashing
 from eth2spec.test.helpers.attester_slashings import get_valid_attester_slashing_by_indices
 from eth2spec.test.helpers.attestations import get_valid_attestation
@@ -192,3 +196,19 @@ def run_test_full_random_operations(spec, state, rng=Random(2080)):
 
     yield 'blocks', [signed_block]
     yield 'post', state
+
+
+def get_random_sync_aggregate(spec, state, fraction_participated=1.0, rng=Random(2099)):
+    committee_indices = compute_committee_indices(spec, state, state.current_sync_committee)
+    participant_count = int(len(committee_indices) * fraction_participated)
+    participants = rng.sample(committee_indices, participant_count)
+    signature = compute_aggregate_sync_committee_signature(
+        spec,
+        state,
+        state.slot,
+        participants,
+    )
+    return spec.SyncAggregate(
+        sync_committee_bits=[index in participants for index in committee_indices],
+        sync_committee_signature=signature,
+    )
diff --git a/tests/core/pyspec/eth2spec/test/utils/random.py b/tests/core/pyspec/eth2spec/test/utils/random.py
index b50a67349..5a7067b3f 100644
--- a/tests/core/pyspec/eth2spec/test/utils/random.py
+++ b/tests/core/pyspec/eth2spec/test/utils/random.py
@@ -47,8 +47,8 @@ BLOCK_TRANSITIONS_COUNT = 2
 # primitives
 ## state
 
-def randomize_state(spec, state):
-    randomize_state_helper(spec, state, exit_fraction=0.1, slash_fraction=0.1)
+def randomize_state(spec, state, exit_fraction=0.1, slash_fraction=0.1):
+    randomize_state_helper(spec, state, exit_fraction=exit_fraction, slash_fraction=slash_fraction)
 
 
 ## epochs
diff --git a/tests/generators/sanity/main.py b/tests/generators/sanity/main.py
index 63efa3897..89e622f1c 100644
--- a/tests/generators/sanity/main.py
+++ b/tests/generators/sanity/main.py
@@ -10,6 +10,7 @@ if __name__ == "__main__":
     ]}
     altair_mods = {**{key: 'eth2spec.test.altair.sanity.test_' + key for key in [
         'blocks',
+        'blocks_random',
     ]}, **phase_0_mods}  # also run the previous phase 0 tests
 
     # Altair-specific test cases are ignored, but should be included after the Merge is rebased onto Altair work.