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-rw-r--r--src/contract_wrappers/token_wrapper.ts110
1 files changed, 110 insertions, 0 deletions
diff --git a/src/contract_wrappers/token_wrapper.ts b/src/contract_wrappers/token_wrapper.ts
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+++ b/src/contract_wrappers/token_wrapper.ts
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+import * as _ from 'lodash';
+import * as BigNumber from 'bignumber.js';
+import {Web3Wrapper} from '../web3_wrapper';
+import {assert} from '../utils/assert';
+import {constants} from '../utils/constants';
+import {ContractWrapper} from './contract_wrapper';
+import * as TokenArtifacts from '../artifacts/Token.json';
+import * as ProxyArtifacts from '../artifacts/Proxy.json';
+import {TokenContract, InternalError} from '../types';
+
+const ALLOWANCE_TO_ZERO_GAS_AMOUNT = 45730;
+
+export class TokenWrapper extends ContractWrapper {
+ private tokenContractsByAddress: {[address: string]: TokenContract};
+ constructor(web3Wrapper: Web3Wrapper) {
+ super(web3Wrapper);
+ this.tokenContractsByAddress = {};
+ }
+ public invalidateContractInstances() {
+ this.tokenContractsByAddress = {};
+ }
+ /**
+ * Returns an owner's ERC20 token balance
+ */
+ public async getBalanceAsync(tokenAddress: string, ownerAddress: string): Promise<BigNumber.BigNumber> {
+ assert.isETHAddressHex('ownerAddress', ownerAddress);
+ assert.isETHAddressHex('tokenAddress', tokenAddress);
+
+ const tokenContract = await this.getTokenContractAsync(tokenAddress);
+ let balance = await tokenContract.balanceOf.call(ownerAddress);
+ // The BigNumber instance returned by Web3 is of a much older version then our own, we therefore
+ // should always re-instantiate the returned BigNumber after retrieval.
+ balance = _.isUndefined(balance) ? new BigNumber(0) : new BigNumber(balance);
+ return balance;
+ }
+ /**
+ * Retrieves the allowance in baseUnits of the ERC20 token set to the 0x proxy contract
+ * by an owner address
+ */
+ public async getProxyAllowanceAsync(tokenAddress: string, ownerAddress: string) {
+ assert.isETHAddressHex('ownerAddress', ownerAddress);
+ assert.isETHAddressHex('tokenAddress', tokenAddress);
+
+ const tokenContract = await this.getTokenContractAsync(tokenAddress);
+ const proxyAddress = await this.getProxyAddressAsync();
+ let allowanceInBaseUnits = await tokenContract.allowance.call(ownerAddress, proxyAddress);
+ allowanceInBaseUnits = _.isUndefined(allowanceInBaseUnits) ?
+ new BigNumber(0) :
+ new BigNumber(allowanceInBaseUnits);
+ return allowanceInBaseUnits;
+ }
+ /**
+ * Sets the 0x proxy contract's allowance to a specified number of a tokens' baseUnits on behalf
+ * of an owner address.
+ */
+ public async setProxyAllowanceAsync(tokenAddress: string, ownerAddress: string,
+ amountInBaseUnits: BigNumber.BigNumber): Promise<void> {
+ assert.isETHAddressHex('ownerAddress', ownerAddress);
+ assert.isETHAddressHex('tokenAddress', tokenAddress);
+ assert.isBigNumber('amountInBaseUnits', amountInBaseUnits);
+
+ const tokenContract = await this.getTokenContractAsync(tokenAddress);
+ const proxyAddress = await this.getProxyAddressAsync();
+ // Hack: for some reason default estimated gas amount causes `base fee exceeds gas limit` exception
+ // on testrpc. Probably related to https://github.com/ethereumjs/testrpc/issues/294
+ // TODO: Debug issue in testrpc and submit a PR, then remove this hack
+ const networkIdIfExists = await this.web3Wrapper.getNetworkIdIfExistsAsync();
+ const gas = networkIdIfExists === constants.TESTRPC_NETWORK_ID ? ALLOWANCE_TO_ZERO_GAS_AMOUNT : undefined;
+ await tokenContract.approve(proxyAddress, amountInBaseUnits, {
+ from: ownerAddress,
+ gas,
+ });
+ }
+ /**
+ * Transfers `amountInBaseUnits` ERC20 tokens from `fromAddress` to `toAddress`.
+ */
+ public async transferAsync(tokenAddress: string, fromAddress: string, toAddress: string,
+ amountInBaseUnits: BigNumber.BigNumber): Promise<void> {
+ assert.isETHAddressHex('tokenAddress', tokenAddress);
+ assert.isETHAddressHex('fromAddress', fromAddress);
+ assert.isETHAddressHex('toAddress', toAddress);
+ assert.isBigNumber('amountInBaseUnits', amountInBaseUnits);
+
+ const tokenContract = await this.getTokenContractAsync(tokenAddress);
+ await tokenContract.transfer(toAddress, amountInBaseUnits, {
+ from: fromAddress,
+ });
+ }
+ private async getTokenContractAsync(tokenAddress: string): Promise<TokenContract> {
+ let tokenContract = this.tokenContractsByAddress[tokenAddress];
+ if (!_.isUndefined(tokenContract)) {
+ return tokenContract;
+ }
+ const contractInstance = await this.instantiateContractIfExistsAsync((TokenArtifacts as any), tokenAddress);
+ tokenContract = contractInstance as TokenContract;
+ this.tokenContractsByAddress[tokenAddress] = tokenContract;
+ return tokenContract;
+ }
+ private async getProxyAddressAsync() {
+ const networkIdIfExists = await this.web3Wrapper.getNetworkIdIfExistsAsync();
+ const proxyNetworkConfigsIfExists = _.isUndefined(networkIdIfExists) ?
+ undefined :
+ (ProxyArtifacts as any).networks[networkIdIfExists];
+ if (_.isUndefined(proxyNetworkConfigsIfExists)) {
+ throw new Error(InternalError.PROXY_ADDRESS_NOT_FOUND);
+ }
+ const proxyAddress = proxyNetworkConfigsIfExists.address;
+ return proxyAddress;
+ }
+}