test for encoding int in abi

Author: Jan Xie

ethereum/tests/test_abi.py

@@ -1,7 +1,10 @@
 import os
+import pytest
 import ethereum.testutils as testutils
 from ethereum.slogging import get_logger
 import ethereum.abi as abi
+from ethereum.utils import zpad
+
 logger = get_logger()
 
 def test_abi_encode_var_sized_array():
@@ -14,6 +17,14 @@ def test_abi_encode_signed_int():
     assert abi.decode_abi(['int8'], abi.encode_abi(['int8'], [1]))[0] == 1
     assert abi.decode_abi(['int8'], abi.encode_abi(['int8'], [-1]))[0] == -1
 
+def test_abi_encode_single_int():
+    assert abi.encode_single(['int', '8', []], -128) == zpad(b'\x80', 32)
+    with pytest.raises(abi.ValueOutOfBounds):
+        assert abi.encode_single(['int', '8', []], -129)
+
+    assert abi.encode_single(['int', '8', []], 127) == zpad(b'\x7f', 32)
+    with pytest.raises(abi.ValueOutOfBounds):
+        assert abi.encode_single(['int', '8', []], 128)
 
 # SETUP TESTS IN GLOBAL NAME SPACE
 def gen_func(filename, testname, testdata):