protocol/contracts/coordinator/src/hash_utils.ts

import { hexConcat } from '@0x/contracts-test-utils';
import { eip712Utils } from '@0x/order-utils';
import { SignedZeroExTransaction } from '@0x/types';
import { signTypedDataUtils } from '@0x/utils';

export const hashUtils = {
    async getApprovalHashBufferAsync(
        transaction: SignedZeroExTransaction,
        verifyingContract: string,
        txOrigin: string,
    ): Promise<Buffer> {
        const typedData = await eip712Utils.createCoordinatorApprovalTypedDataAsync(
            transaction,
            verifyingContract,
            txOrigin,
        );
        const hashBuffer = signTypedDataUtils.generateTypedDataHash(typedData);
        return hashBuffer;
    },
    async getApprovalHashHexAsync(
        transaction: SignedZeroExTransaction,
        verifyingContract: string,
        txOrigin: string,
    ): Promise<string> {
        const hashHex = hexConcat(await hashUtils.getApprovalHashBufferAsync(transaction, verifyingContract, txOrigin));
        return hashHex;
    },
};