Fix bug where to_wei didn't handle decimals correctly (#421)

* Fix bug where to_wei didn't handle decimals correctly
* Fix pytest github action

Co-authored-by: Calina Cenan <[email protected]>

.github/workflows/pytest.yml

@@ -27,10 +27,7 @@ jobs:
       - name: Run Barge
         working-directory: ${{ github.workspace }}/barge
         env:
-          OPERATOR_SERVICE_VERSION: refactor_signatures
           CONTRACTS_VERSION: v1.0.0-alpha.28
-          AQUARIUS_VERSION: refactor_signatures
-          PROVIDER_VERSION: refactor_signatures
         run: |
           bash -x start_ocean.sh --no-dashboard 2>&1 --with-rbac --with-provider2 --with-c2d > start_ocean.log &
           for i in $(seq 1 150); do

ocean_provider/utils/currency.py

@@ -1,7 +1,7 @@
-from decimal import ROUND_DOWN, Context, Decimal
+from decimal import ROUND_DOWN, Context, Decimal, localcontext
 from typing import Union
 
-from web3.main import Web3
+from eth_utils.currency import units
 
 """The maximum uint256 value."""
 MAX_UINT256 = 2**256 - 1
@@ -32,28 +32,43 @@
 MAX_ETHER = Decimal(MAX_WEI).scaleb(-18, context=ETHEREUM_DECIMAL_CONTEXT)
 
 
-def to_wei(
-    amount_in_ether: Union[Decimal, str, int], decimals: int = DECIMALS_18
+def to_wei(amount_in_ether: Union[Decimal, str, int]) -> int:
+    return parse_units(amount_in_ether, DECIMALS_18)
+
+
+def parse_units(
+    amount: Union[Decimal, str, int], unit_name: Union[str, int] = DECIMALS_18
 ) -> int:
     """
-    Convert token amount to wei from ether, quantized to the specified number of decimal places
+    Convert token amount from a formatted unit to an EVM-compatible integer.
     float input is purposfully not supported
     """
-    amount_in_ether = normalize_and_validate_ether(amount_in_ether)
-    decimal_places = Decimal(10) ** -abs(decimals)
-    return Web3.toWei(
-        amount_in_ether.quantize(decimal_places, context=ETHEREUM_DECIMAL_CONTEXT),
-        "ether",
+    num_decimals = (
+        int(units[unit_name].log10()) if isinstance(unit_name, str) else unit_name
     )
 
+    decimal_amount = normalize_and_validate_unit(amount, num_decimals)
+
+    if decimal_amount == Decimal(0):
+        return 0
+
+    unit_value = Decimal(10) ** num_decimals
+
+    with localcontext(ETHEREUM_DECIMAL_CONTEXT):
+        return int(decimal_amount * unit_value)
+
 
-def normalize_and_validate_ether(amount_in_ether: Union[Decimal, str, int]) -> Decimal:
+def normalize_and_validate_unit(
+    amount: Union[Decimal, str, int], decimals: int = DECIMALS_18
+) -> Decimal:
     """Returns an amount in ether, encoded as a Decimal
     Takes Decimal, str, or int as input. Purposefully does not support float."""
-    if isinstance(amount_in_ether, str) or isinstance(amount_in_ether, int):
-        amount_in_ether = Decimal(amount_in_ether)
+    if isinstance(amount, str) or isinstance(amount, int):
+        amount = Decimal(amount)
 
-    if abs(amount_in_ether) > MAX_ETHER:
-        raise ValueError("Token abs(amount_in_ether) exceeds MAX_ETHER.")
+    if abs(amount) > Decimal(MAX_WEI).scaleb(
+        -decimals, context=ETHEREUM_DECIMAL_CONTEXT
+    ):
+        raise ValueError("Token amount exceeds maximum.")
 
-    return amount_in_ether
+    return amount

ocean_provider/utils/provider_fees.py

@@ -1,14 +1,14 @@
-from datetime import datetime
 import json
 import logging
 import os
+from datetime import datetime
 from typing import Any, Dict, List
 
 from eth_keys import KeyAPI
 from eth_keys.backends import NativeECCBackend
 from ocean_provider.requests_session import get_requests_session
 from ocean_provider.utils.basics import LocalFileAdapter, get_provider_wallet, get_web3
-from ocean_provider.utils.currency import to_wei
+from ocean_provider.utils.currency import parse_units
 from ocean_provider.utils.datatoken import get_datatoken_contract
 from ocean_provider.utils.services import Service
 from ocean_provider.utils.util import get_compute_environments_endpoint, get_environment
@@ -107,4 +107,4 @@ def get_provider_fee_amount(valid_until, compute_env, web3, provider_fee_token):
     dt = get_datatoken_contract(web3, provider_fee_token)
     decimals = dt.caller.decimals()
 
-    return to_wei(str(provider_fee_amount), decimals)
+    return parse_units(str(provider_fee_amount), decimals)

ocean_provider/utils/test/test_currency.py

@@ -5,16 +5,24 @@
 from decimal import Decimal, localcontext
 
 import pytest
-
 from ocean_provider.utils.currency import (
     ETHEREUM_DECIMAL_CONTEXT,
     MAX_ETHER,
     MAX_WEI,
     MIN_ETHER,
     MIN_WEI,
+    parse_units,
     to_wei,
 )
 
+USDT_DECIMALS = 6
+MIN_USDT = Decimal("0.000001")
+MAX_USDT = Decimal(MAX_WEI).scaleb(-USDT_DECIMALS, context=ETHEREUM_DECIMAL_CONTEXT)
+
+SEVEN_DECIMALS = 7
+MIN_SEVEN = Decimal("0.0000001")
+MAX_SEVEN = Decimal(MAX_WEI).scaleb(-SEVEN_DECIMALS, context=ETHEREUM_DECIMAL_CONTEXT)
+
 
 @pytest.mark.unit
 def test_to_wei():
@@ -47,18 +55,42 @@ def test_to_wei():
         to_wei(MAX_ETHER) == MAX_WEI
     ), "Conversion from maximum ether to maximum wei failed."
 
-    with pytest.raises(ValueError):
-        # Use ETHEREUM_DECIMAL_CONTEXT when performing arithmetic on MAX_ETHER
-        with localcontext(ETHEREUM_DECIMAL_CONTEXT):
+    # Use ETHEREUM_DECIMAL_CONTEXT when performing arithmetic on MAX_ETHER
+    with localcontext(ETHEREUM_DECIMAL_CONTEXT):
+        with pytest.raises(ValueError):
             to_wei(MAX_ETHER + 1)
 
-    USDT_DECIMALS = 6
-    assert (
-        to_wei("0", USDT_DECIMALS) == 0
-    ), "Zero ether of USDT should equal zero wei of USDT"
-    assert (
-        to_wei("0.123456789123456789", USDT_DECIMALS) == 123456000_000000000
-    ), "Conversion from ether to wei using decimals failed"
-    assert (
-        to_wei("1.123456789123456789", USDT_DECIMALS) == 1_123456000_000000000
-    ), "Conversion from ether to wei using decimals failed"
+
+@pytest.mark.unit
+def test_parse_units():
+    """Test the parse_units function"""
+    assert parse_units("0", USDT_DECIMALS) == 0
+    assert parse_units("0.123456789123456789", USDT_DECIMALS) == 123456
+    assert parse_units("1.123456789123456789", USDT_DECIMALS) == 1_123456
+    assert parse_units("5278.02", USDT_DECIMALS) == 5278_020000
+    assert parse_units(MIN_USDT, USDT_DECIMALS) == MIN_WEI
+    assert parse_units(MAX_USDT, USDT_DECIMALS) == MAX_WEI
+
+    # Use ETHEREUM_DECIMAL_CONTEXT when performing arithmetic on MAX_USDT
+    with localcontext(ETHEREUM_DECIMAL_CONTEXT):
+        with pytest.raises(ValueError):
+            parse_units(MAX_USDT + 1, USDT_DECIMALS)
+
+    assert parse_units("0", "mwei") == 0
+    assert parse_units("0.123456789123456789", "mwei") == 123456
+    assert parse_units("1.123456789123456789", "mwei") == 1_123456
+    assert parse_units("5278.02", "mwei") == 5278_020000
+    assert parse_units(MIN_USDT, "mwei") == MIN_WEI
+    assert parse_units(MAX_USDT, "mwei") == MAX_WEI
+
+    # Use ETHEREUM_DECIMAL_CONTEXT when performing arithmetic on MAX_USDT
+    with localcontext(ETHEREUM_DECIMAL_CONTEXT):
+        with pytest.raises(ValueError):
+            parse_units(MAX_USDT + 1, "mwei")
+
+    assert parse_units("0", SEVEN_DECIMALS) == 0
+    assert parse_units("0.123456789", SEVEN_DECIMALS) == 1234567
+    assert parse_units("1.123456789", SEVEN_DECIMALS) == 1_1234567
+    assert parse_units("5278.02", SEVEN_DECIMALS) == 5278_0200000
+    assert parse_units(MIN_SEVEN, SEVEN_DECIMALS) == MIN_WEI
+    assert parse_units(MAX_SEVEN, SEVEN_DECIMALS) == MAX_WEI