metamask-extension/ui/hooks/useGasFeeErrors.js

import { useMemo } from 'react';
import { useSelector } from 'react-redux';
import { GAS_ESTIMATE_TYPES, GAS_LIMITS } from '../../shared/constants/gas';
import {
  conversionLessThan,
  conversionGreaterThan,
} from '../../shared/modules/conversion.utils';
import {
  checkNetworkAndAccountSupports1559,
  getSelectedAccount,
} from '../selectors';
import { addHexes } from '../helpers/utils/conversions.util';
import { isLegacyTransaction } from '../helpers/utils/transactions.util';
import {
  bnGreaterThan,
  bnLessThan,
  bnLessThanEqualTo,
} from '../helpers/utils/util';
import { GAS_FORM_ERRORS } from '../helpers/constants/gas';

const HIGH_FEE_WARNING_MULTIPLIER = 1.5;

const validateGasLimit = (gasLimit, minimumGasLimit) => {
  const gasLimitTooLow = conversionLessThan(
    { value: gasLimit, fromNumericBase: 'dec' },
    { value: minimumGasLimit || GAS_LIMITS.SIMPLE, fromNumericBase: 'hex' },
  );

  if (gasLimitTooLow) return GAS_FORM_ERRORS.GAS_LIMIT_OUT_OF_BOUNDS;
  return undefined;
};

const validateMaxPriorityFee = (maxPriorityFeePerGasToUse, supportsEIP1559) => {
  if (supportsEIP1559 && bnLessThanEqualTo(maxPriorityFeePerGasToUse, 0)) {
    return GAS_FORM_ERRORS.MAX_PRIORITY_FEE_BELOW_MINIMUM;
  }
  return undefined;
};

const validateMaxFee = (
  maxFeePerGasToUse,
  maxPriorityFeeError,
  maxPriorityFeePerGasToUse,
  supportsEIP1559,
) => {
  if (maxPriorityFeeError) return undefined;
  if (
    supportsEIP1559 &&
    bnGreaterThan(maxPriorityFeePerGasToUse, maxFeePerGasToUse)
  ) {
    return GAS_FORM_ERRORS.MAX_FEE_IMBALANCE;
  }
  return undefined;
};

const validateGasPrice = (
  isFeeMarketGasEstimate,
  gasPriceToUse,
  supportsEIP1559,
  transaction,
) => {
  if (
    (!supportsEIP1559 || transaction?.txParams?.gasPrice) &&
    !isFeeMarketGasEstimate &&
    bnLessThanEqualTo(gasPriceToUse, 0)
  ) {
    return GAS_FORM_ERRORS.GAS_PRICE_TOO_LOW;
  }
  return undefined;
};

const getMaxPriorityFeeWarning = (
  gasFeeEstimates,
  isFeeMarketGasEstimate,
  isGasEstimatesLoading,
  maxPriorityFeePerGasToUse,
  supportsEIP1559,
) => {
  if (!supportsEIP1559 || !isFeeMarketGasEstimate || isGasEstimatesLoading)
    return undefined;
  if (
    bnLessThan(
      maxPriorityFeePerGasToUse,
      gasFeeEstimates?.low?.suggestedMaxPriorityFeePerGas,
    )
  ) {
    return GAS_FORM_ERRORS.MAX_PRIORITY_FEE_TOO_LOW;
  }
  if (
    gasFeeEstimates?.high &&
    bnGreaterThan(
      maxPriorityFeePerGasToUse,
      gasFeeEstimates.high.suggestedMaxPriorityFeePerGas *
        HIGH_FEE_WARNING_MULTIPLIER,
    )
  ) {
    return GAS_FORM_ERRORS.MAX_PRIORITY_FEE_HIGH_WARNING;
  }
  return undefined;
};

const getMaxFeeWarning = (
  gasFeeEstimates,
  isGasEstimatesLoading,
  isFeeMarketGasEstimate,
  maxFeeError,
  maxPriorityFeeError,
  maxFeePerGasToUse,
  supportsEIP1559,
) => {
  if (
    maxPriorityFeeError ||
    maxFeeError ||
    !isFeeMarketGasEstimate ||
    !supportsEIP1559
  ) {
    return undefined;
  }
  if (
    !isGasEstimatesLoading &&
    bnLessThan(maxFeePerGasToUse, gasFeeEstimates?.low?.suggestedMaxFeePerGas)
  ) {
    return GAS_FORM_ERRORS.MAX_FEE_TOO_LOW;
  }
  if (
    gasFeeEstimates?.high &&
    bnGreaterThan(
      maxFeePerGasToUse,
      gasFeeEstimates.high.suggestedMaxFeePerGas * HIGH_FEE_WARNING_MULTIPLIER,
    )
  ) {
    return GAS_FORM_ERRORS.MAX_FEE_HIGH_WARNING;
  }
  return undefined;
};

const getBalanceError = (minimumCostInHexWei, transaction, ethBalance) => {
  const minimumTxCostInHexWei = addHexes(
    minimumCostInHexWei,
    transaction?.txParams?.value || '0x0',
  );

  return conversionGreaterThan(
    { value: minimumTxCostInHexWei, fromNumericBase: 'hex' },
    { value: ethBalance, fromNumericBase: 'hex' },
  );
};

/**
 * @typedef {Object} GasFeeErrorsReturnType
 * @property {Object} [gasErrors] - combined map of errors and warnings.
 * @property {boolean} [hasGasErrors] - true if there are errors that can block submission.
 * @property {Object} gasWarnings - map of gas warnings for EIP-1559 fields.
 * @property {boolean} [balanceError] - true if user balance is less than transaction value.
 * @property {boolean} [estimatesUnavailableWarning] - true if supportsEIP1559 is true and
 * estimate is not of type fee-market.
 */
export function useGasFeeErrors({
  transaction,
  gasEstimateType,
  gasFeeEstimates,
  gasLimit,
  gasPriceToUse,
  isGasEstimatesLoading,
  maxPriorityFeePerGasToUse,
  maxFeePerGasToUse,
  minimumCostInHexWei,
  minimumGasLimit,
}) {
  const supportsEIP1559 =
    useSelector(checkNetworkAndAccountSupports1559) &&
    !isLegacyTransaction(transaction?.txParams);

  const isFeeMarketGasEstimate =
    gasEstimateType === GAS_ESTIMATE_TYPES.FEE_MARKET;

  // Get all errors
  const gasLimitError = validateGasLimit(gasLimit, minimumGasLimit);

  const maxPriorityFeeError = validateMaxPriorityFee(
    maxPriorityFeePerGasToUse,
    supportsEIP1559,
  );

  const maxFeeError = validateMaxFee(
    maxFeePerGasToUse,
    maxPriorityFeeError,
    maxPriorityFeePerGasToUse,
    supportsEIP1559,
  );

  const gasPriceError = validateGasPrice(
    isFeeMarketGasEstimate,
    gasPriceToUse,
    supportsEIP1559,
    transaction,
  );

  // Get all warnings
  const maxPriorityFeeWarning = getMaxPriorityFeeWarning(
    gasFeeEstimates,
    isFeeMarketGasEstimate,
    isGasEstimatesLoading,
    maxPriorityFeePerGasToUse,
    supportsEIP1559,
  );

  const maxFeeWarning = getMaxFeeWarning(
    gasFeeEstimates,
    isGasEstimatesLoading,
    isFeeMarketGasEstimate,
    maxFeeError,
    maxPriorityFeeError,
    maxFeePerGasToUse,
    supportsEIP1559,
  );

  // Separating errors from warnings so we can know which value problems
  // are blocking or simply useful information for the users

  const gasErrors = useMemo(() => {
    const errors = {};
    if (gasLimitError) errors.gasLimit = gasLimitError;
    if (maxPriorityFeeError) errors.maxPriorityFee = maxPriorityFeeError;
    if (maxFeeError) errors.maxFee = maxFeeError;
    if (gasPriceError) errors.gasPrice = gasPriceError;
    return errors;
  }, [gasLimitError, maxPriorityFeeError, maxFeeError, gasPriceError]);

  const gasWarnings = useMemo(() => {
    const warnings = {};
    if (maxPriorityFeeWarning) warnings.maxPriorityFee = maxPriorityFeeWarning;
    if (maxFeeWarning) warnings.maxFee = maxFeeWarning;
    return warnings;
  }, [maxPriorityFeeWarning, maxFeeWarning]);

  const estimatesUnavailableWarning =
    supportsEIP1559 && !isFeeMarketGasEstimate;

  // Determine if we have any errors which should block submission
  const hasGasErrors = Boolean(Object.keys(gasErrors).length);

  // Combine the warnings and errors into one object for easier use within the UI.
  // This object should have no effect on whether or not the user can submit the form
  const errorsAndWarnings = useMemo(
    () => ({
      ...gasWarnings,
      ...gasErrors,
    }),
    [gasErrors, gasWarnings],
  );

  const { balance: ethBalance } = useSelector(getSelectedAccount);
  const balanceError = getBalanceError(
    minimumCostInHexWei,
    transaction,
    ethBalance,
  );

  return {
    gasErrors: errorsAndWarnings,
    hasGasErrors,
    gasWarnings,
    balanceError,
    estimatesUnavailableWarning,
  };
}