protocol/contracts/test-utils/src/transaction_factory.ts

55 lines
2.3 KiB
TypeScript

import { generatePseudoRandomSalt, transactionHashUtils } from '@0x/order-utils';
import { SignatureType, SignedZeroExTransaction, ZeroExTransaction } from '@0x/types';
import { BigNumber } from '@0x/utils';
import * as ethUtil from 'ethereumjs-util';
import { getLatestBlockTimestampAsync } from './block_timestamp';
import { constants } from './constants';
import { signingUtils } from './signing_utils';
export class TransactionFactory {
private readonly _signerBuff: Buffer;
private readonly _exchangeAddress: string;
private readonly _privateKey: Buffer;
private readonly _chainId: number;
constructor(privateKey: Buffer, exchangeAddress: string, chainId: number) {
this._privateKey = privateKey;
this._exchangeAddress = exchangeAddress;
this._chainId = chainId;
this._signerBuff = ethUtil.privateToAddress(this._privateKey);
}
public async newSignedTransactionAsync(
customTransactionParams: Partial<ZeroExTransaction>,
signatureType: SignatureType = SignatureType.EthSign,
): Promise<SignedZeroExTransaction> {
if (customTransactionParams.data === undefined) {
throw new Error('Error: ZeroExTransaction data field must be supplied');
}
const tenMinutesInSeconds = 10 * 60;
const currentBlockTimestamp = await getLatestBlockTimestampAsync();
const salt = generatePseudoRandomSalt();
const signerAddress = `0x${this._signerBuff.toString('hex')}`;
const transaction = {
salt,
signerAddress,
data: customTransactionParams.data,
expirationTimeSeconds: new BigNumber(currentBlockTimestamp).plus(tenMinutesInSeconds),
gasPrice: new BigNumber(constants.DEFAULT_GAS_PRICE),
domain: {
verifyingContractAddress: this._exchangeAddress,
chainId: this._chainId,
},
...customTransactionParams,
};
const transactionHashBuffer = transactionHashUtils.getTransactionHashBuffer(transaction);
const signature = signingUtils.signMessage(transactionHashBuffer, this._privateKey, signatureType);
const signedTransaction = {
...transaction,
signature: `0x${signature.toString('hex')}`,
};
return signedTransaction;
}
}