Issue #2095 - Provide constants for e.g. the zero address and max uin…

…t256 (#2109)
ethereum · Aug 26, 2021 · 73d7da0 · 73d7da0
1 parent 13685d6
commit 73d7da0
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Showing 11 changed files with 79 additions and 16 deletions.
diff --git a/docs/constants.rst b/docs/constants.rst
@@ -0,0 +1,30 @@
+.. _constants:
+
+Constants
+=========
+
+The web3.contants module contains commonly used values.
+
+Strings
+*******
+
+.. code-block:: python
+
+    #The Address Zero, which is 20 bytes (40 nibbles) of zero.
+    web3.constants.ADDRESS_ZERO
+    
+    #The hexadecimal version of Max uint256.
+    web3.constants.MAX_INT
+    
+    #The Hash Zero, which is 32 bytes (64 nibbles) of zero.
+    web3.constants.HASH_ZERO  
+
+Int
+***
+
+.. code-block:: python
+
+    #The amount of Wei in one Ether
+    web3.constants.WEI_PER_ETHER
+    
+
diff --git a/docs/index.rst b/docs/index.rst
@@ -68,6 +68,7 @@ Table of Contents
     web3.parity
     gas_price
     ens
+    constants
 
 .. toctree::
     :maxdepth: 1

diff --git a/newsfragments/2109.feature.rst b/newsfragments/2109.feature.rst
@@ -0,0 +1 @@
+Add constants for the zero address, zero hash, max int, and wei per ether.
diff --git a/tests/core/contracts/test_contract_deployment.py b/tests/core/contracts/test_contract_deployment.py
@@ -5,6 +5,10 @@
     decode_hex,
 )
 
+from web3 import (
+    constants,
+)
+
 
 def test_contract_deployment_no_constructor(web3, MathContract,
                                             MATH_RUNTIME):
@@ -56,7 +60,7 @@ def test_contract_deployment_with_constructor_with_arguments(web3,
 
 @pytest.mark.parametrize('constructor_arg', (
     b'1234\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00',  # noqa: E501
-    '0x0000000000000000000000000000000000000000000000000000000000000000')
+    constants.HASH_ZERO)
 )
 def test_contract_deployment_with_constructor_with_arguments_strict(w3_strict_abi,
                                                                     WithConstructorArgumentsContractStrict,  # noqa: E501

diff --git a/tests/core/contracts/test_contract_method_abi_encoding.py b/tests/core/contracts/test_contract_method_abi_encoding.py
@@ -1,6 +1,9 @@
 import json
 import pytest
 
+from web3 import (
+    constants,
+)
 from web3.exceptions import (
     ValidationError,
 )
@@ -125,7 +128,7 @@ def test_contract_abi_encoding_strict_with_error(w3_strict_abi, arguments):
         ),
         pytest.param(
             ABI_C,
-            ['0x0000000000000000000000000000000000000000000000000000000000000000'],
+            [constants.HASH_ZERO],
             None,
             '0x9f3fab580000000000000000000000000000000000000000000000000000000000000000',
             id='ABI_C, valid hexstring args, no data'

diff --git a/tests/core/gas-strategies/test_time_based_gas_price_strategy.py b/tests/core/gas-strategies/test_time_based_gas_price_strategy.py
@@ -1,6 +1,9 @@
 import pytest
 
-from web3 import Web3
+from web3 import (
+    Web3,
+    constants,
+)
 from web3.exceptions import (
     ValidationError,
 )
@@ -87,7 +90,7 @@ def _get_block_by_something(method, params):
         return {
             'hash': '0x0000000000000000000000000000000000000000000000000000000000000001',
             'number': 1,
-            'parentHash': '0x0000000000000000000000000000000000000000000000000000000000000000',
+            'parentHash': constants.HASH_ZERO,
             'transactions': [
                 {'gasPrice': 30},
                 {'gasPrice': 35},
@@ -100,7 +103,7 @@ def _get_block_by_something(method, params):
         block_identifier == '0x0'
     ):
         return {
-            'hash': '0x0000000000000000000000000000000000000000000000000000000000000000',
+            'hash': constants.HASH_ZERO,
             'number': 0,
             'parentHash': None,
             'transactions': [

diff --git a/tests/core/middleware/test_name_to_address_middleware.py b/tests/core/middleware/test_name_to_address_middleware.py
@@ -1,6 +1,9 @@
 import pytest
 
-from web3 import Web3
+from web3 import (
+    Web3,
+    constants,
+)
 from web3.exceptions import (
     InvalidAddress,
 )
@@ -13,7 +16,7 @@
 )
 
 NAME = "dump.eth"
-ADDRESS = "0x0000000000000000000000000000000000000000"
+ADDRESS = constants.ADDRESS_ZERO
 BALANCE = 0
 
 

diff --git a/tests/integration/generate_fixtures/common.py b/tests/integration/generate_fixtures/common.py
@@ -12,6 +12,9 @@
     to_text,
 )
 
+from web3 import (
+    constants,
+)
 from web3.exceptions import (
     TransactionNotFound,
 )
@@ -57,11 +60,11 @@
         "0000000000000000000000000000000000000006": {"balance": "1"},
     },
     "timestamp": "0x00",
-    "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
+    "parentHash": constants.HASH_ZERO,
     "extraData": "0x3535353535353535353535353535353535353535353535353535353535353535",
     "gasLimit": "0x3b9aca00",  # 1,000,000,000
     "difficulty": "0x10000",
-    "mixhash": "0x0000000000000000000000000000000000000000000000000000000000000000",
+    "mixhash": constants.HASH_ZERO,
     "coinbase": COINBASE
 }
 

diff --git a/tests/integration/generate_fixtures/parity.py b/tests/integration/generate_fixtures/parity.py
@@ -18,7 +18,10 @@
 from tests.utils import (
     get_open_port,
 )
-from web3 import Web3
+from web3 import (
+    Web3,
+    constants,
+)
 
 CHAIN_CONFIG = {
     "name": "CrossClient",
@@ -75,13 +78,13 @@
         "seal": {
             "ethereum": {
                 "nonce": "0x0000000000000042",
-                "mixHash": "0x0000000000000000000000000000000000000000000000000000000000000000"
+                "mixHash": constants.HASH_ZERO
             }
         },
         "difficulty": "0x10000",
         "author": common.COINBASE,
         "timestamp": "0x00",
-        "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
+        "parentHash": constants.HASH_ZERO,
         "extraData": "0x3535353535353535353535353535353535353535353535353535353535353535",
         "gasLimit": "0x1000000"
     },

diff --git a/web3/_utils/module_testing/personal_module.py b/web3/_utils/module_testing/personal_module.py
@@ -18,6 +18,9 @@
     HexBytes,
 )
 
+from web3 import (
+    constants,
+)
 from web3.types import (  # noqa: F401
     TxParams,
     Wei,
@@ -143,7 +146,7 @@ def test_personal_send_transaction(
         unlockable_account_dual_type: ChecksumAddress,
         unlockable_account_pw: str,
     ) -> None:
-        assert web3.eth.get_balance(unlockable_account_dual_type) > web3.toWei(1, 'ether')
+        assert web3.eth.get_balance(unlockable_account_dual_type) > constants.WEI_PER_ETHER
         txn_params: TxParams = {
             'from': unlockable_account_dual_type,
             'to': unlockable_account_dual_type,
@@ -167,7 +170,7 @@ def test_personal_sendTransaction_deprecated(
         unlockable_account_dual_type: ChecksumAddress,
         unlockable_account_pw: str,
     ) -> None:
-        assert web3.eth.get_balance(unlockable_account_dual_type) > web3.toWei(1, 'ether')
+        assert web3.eth.get_balance(unlockable_account_dual_type) > constants.WEI_PER_ETHER
         txn_params: TxParams = {
             'from': unlockable_account_dual_type,
             'to': unlockable_account_dual_type,
@@ -460,7 +463,7 @@ def test_personal_send_transaction(
         unlockable_account_dual_type: ChecksumAddress,
         unlockable_account_pw: str,
     ) -> None:
-        assert web3.eth.get_balance(unlockable_account_dual_type) > web3.toWei(1, 'ether')
+        assert web3.eth.get_balance(unlockable_account_dual_type) > constants.WEI_PER_ETHER
         txn_params: TxParams = {
             'from': unlockable_account_dual_type,
             'to': unlockable_account_dual_type,
@@ -484,7 +487,7 @@ def test_personal_sendTransaction_deprecated(
         unlockable_account_dual_type: ChecksumAddress,
         unlockable_account_pw: str,
     ) -> None:
-        assert web3.eth.get_balance(unlockable_account_dual_type) > web3.toWei(1, 'ether')
+        assert web3.eth.get_balance(unlockable_account_dual_type) > constants.WEI_PER_ETHER
         txn_params: TxParams = {
             'from': unlockable_account_dual_type,
             'to': unlockable_account_dual_type,

diff --git a/web3/constants.py b/web3/constants.py
@@ -0,0 +1,9 @@
+# Constants as Strings
+ADDRESS_ZERO = "0x0000000000000000000000000000000000000000"
+
+MAX_INT = "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
+
+HASH_ZERO = "0x0000000000000000000000000000000000000000000000000000000000000000"
+
+# Constants as Int
+WEI_PER_ETHER = 1000000000000000000