From b6b4d3cbafb44f176ad236abaebf304dac5365bc Mon Sep 17 00:00:00 2001
From: Justin Drake <drakefjustin@gmail.com>
Date: Wed, 1 May 2019 09:30:08 +0100
Subject: [PATCH] Add get_state_root in tests

---
 test_libs/pyspec/tests/test_sanity.py | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/test_libs/pyspec/tests/test_sanity.py b/test_libs/pyspec/tests/test_sanity.py
index b7d31f122..cdc60aa0a 100644
--- a/test_libs/pyspec/tests/test_sanity.py
+++ b/test_libs/pyspec/tests/test_sanity.py
@@ -9,6 +9,7 @@ from eth2spec.utils.minimal_ssz import signing_root
 from eth2spec.phase0.spec import (
     # constants
     ZERO_HASH,
+    SLOTS_PER_HISTORICAL_ROOT,
     # SSZ
     Deposit,
     Transfer,
@@ -17,7 +18,6 @@ from eth2spec.phase0.spec import (
     get_active_validator_indices,
     get_beacon_proposer_index,
     get_block_root_at_slot,
-    get_state_root,
     get_current_epoch,
     get_domain,
     advance_slot,
@@ -51,6 +51,14 @@ from .helpers import (
 pytestmark = pytest.mark.sanity
 
 
+def get_state_root(state, slot) -> bytes:
+    """
+    Return the state root at a recent ``slot``.
+    """
+    assert slot < state.slot <= slot + SLOTS_PER_HISTORICAL_ROOT
+    return state.latest_state_roots[slot % SLOTS_PER_HISTORICAL_ROOT]
+
+
 def test_slot_transition(state):
     test_state = deepcopy(state)
     cache_state(test_state)