Update instances of int_to_bytes

scripts/phase0/build_spec.py

@@ -15,15 +15,11 @@ from typing import (
 from eth2spec.utils.minimal_ssz import *
 from eth2spec.utils.bls_stub import *
 
-""")
-    for i in (1, 2, 3, 4, 8, 32, 48, 96):
-        code_lines.append("def int_to_bytes%d(x): return x.to_bytes(%d, 'little')" % (i, i))
-
-    code_lines.append("""
-
 # stub, will get overwritten by real var
 SLOTS_PER_EPOCH = 64
 
+def int_to_bytes(integer: int, length: int) -> bytes:
+    return integer.to_bytes(length, 'little')
 
 Slot = NewType('Slot', int)  # uint64
 Epoch = NewType('Epoch', int)  # uint64

specs/core/0_beacon-chain.md

@@ -195,7 +195,7 @@ These configurations are updated for releases, but may be out of sync during `de
 | `GENESIS_EPOCH` | `0` |
 | `FAR_FUTURE_EPOCH` | `2**64 - 1` |
 | `ZERO_HASH` | `int_to_bytes(0, length=32)` |
-| `BLS_WITHDRAWAL_PREFIX_BYTE` | `int_to_bytes(0, length=1)` |
+| `BLS_WITHDRAWAL_PREFIX` | `0` |
 
 ### Time parameters
 
@@ -1840,7 +1840,7 @@ def process_transfer(state: BeaconState, transfer: Transfer) -> None:
     # Verify that the pubkey is valid
     assert (
         state.validator_registry[transfer.sender].withdrawal_credentials ==
-        BLS_WITHDRAWAL_PREFIX_BYTE + hash(transfer.pubkey)[1:]
+        int_to_bytes(BLS_WITHDRAWAL_PREFIX, length=1) + hash(transfer.pubkey)[1:]
     )
     # Verify that the signature is valid
     assert bls_verify(transfer.pubkey, signing_root(transfer), transfer.signature, get_domain(state, DOMAIN_TRANSFER))

specs/core/1_shard-data-chains.md

@@ -180,7 +180,7 @@ def get_shard_proposer_index(state: BeaconState,
                              slot: Slot) -> ValidatorIndex:
     # Randomly shift persistent committee
     persistent_committee = get_persistent_committee(state, shard, slot)
-    seed = hash(state.current_shuffling_seed + int_to_bytes8(shard) + int_to_bytes8(slot))
+    seed = hash(state.current_shuffling_seed + int_to_bytes(shard, length=8) + int_to_bytes(slot, length=8))
     random_index = bytes_to_int(seed[0:8]) % len(persistent_committee)
     persistent_committee = persistent_committee[random_index:] + persistent_committee[:random_index]
 

specs/light_client/sync_protocol.md

@@ -146,7 +146,7 @@ def compute_committee(header: BeaconBlockHeader,
     ]
     def get_switchover_epoch(index):
         return (
-            bytes_to_int(hash(validator_memory.earlier_period_data.seed + int_to_bytes3(index))[0:8]) %
+            bytes_to_int(hash(validator_memory.earlier_period_data.seed + int_to_bytes(index, length=3))[0:8]) %
             PERSISTENT_COMMITTEE_PERIOD
         )
 

test_generators/shuffling/main.py

@@ -15,7 +15,7 @@ def shuffling_case(seed: spec.Bytes32, count: int):
 
 @to_tuple
 def shuffling_test_cases():
-    for seed in [spec.hash(spec.int_to_bytes4(seed_init_value)) for seed_init_value in range(30)]:
+    for seed in [spec.hash(spec.int_to_bytes(seed_init_value, length=4)) for seed_init_value in range(30)]:
         for count in [0, 1, 2, 3, 5, 10, 33, 100, 1000]:
             yield shuffling_case(seed, count)