Refactor ERC20 token transfer proxy and it's tests

packages/contract-wrappers/src/contract_wrappers/erc20_proxy_wrapper.ts

@@ -0,0 +1,73 @@
+import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import { ContractAbi } from 'ethereum-types';
+import * as _ from 'lodash';
+
+import { artifacts } from '../artifacts';
+import { assert } from '../utils/assert';
+
+import { ContractWrapper } from './contract_wrapper';
+import { ERC20ProxyContract } from './generated/erc20_proxy';
+
+/**
+ * This class includes the functionality related to interacting with the ERC20Proxy contract.
+ */
+export class ERC20ProxyWrapper extends ContractWrapper {
+    public abi: ContractAbi = artifacts.ERC20Proxy.compilerOutput.abi;
+    private _erc20ProxyContractIfExists?: ERC20ProxyContract;
+    private _contractAddressIfExists?: string;
+    constructor(web3Wrapper: Web3Wrapper, networkId: number, contractAddressIfExists?: string) {
+        super(web3Wrapper, networkId);
+        this._contractAddressIfExists = contractAddressIfExists;
+    }
+    /**
+     * Check if the Exchange contract address is authorized by the ERC20Proxy contract.
+     * @param   exchangeContractAddress     The hex encoded address of the Exchange contract to call.
+     * @return  Whether the exchangeContractAddress is authorized.
+     */
+    public async isAuthorizedAsync(exchangeContractAddress: string): Promise<boolean> {
+        assert.isETHAddressHex('exchangeContractAddress', exchangeContractAddress);
+        const normalizedExchangeContractAddress = exchangeContractAddress.toLowerCase();
+        const ERC20ProxyContractInstance = await this._getERC20ProxyContractAsync();
+        const isAuthorized = await ERC20ProxyContractInstance.authorized.callAsync(normalizedExchangeContractAddress);
+        return isAuthorized;
+    }
+    /**
+     * Get the list of all Exchange contract addresses authorized by the ERC20Proxy contract.
+     * @return  The list of authorized addresses.
+     */
+    public async getAuthorizedAddressesAsync(): Promise<string[]> {
+        const ERC20ProxyContractInstance = await this._getERC20ProxyContractAsync();
+        const authorizedAddresses = await ERC20ProxyContractInstance.getAuthorizedAddresses.callAsync();
+        return authorizedAddresses;
+    }
+    /**
+     * Retrieves the Ethereum address of the ERC20Proxy contract deployed on the network
+     * that the user-passed web3 provider is connected to.
+     * @returns The Ethereum address of the ERC20Proxy contract being used.
+     */
+    public getContractAddress(): string {
+        const contractAddress = this._getContractAddress(artifacts.ERC20Proxy, this._contractAddressIfExists);
+        return contractAddress;
+    }
+    // tslint:disable-next-line:no-unused-variable
+    private _invalidateContractInstance(): void {
+        delete this._erc20ProxyContractIfExists;
+    }
+    private async _getERC20ProxyContractAsync(): Promise<ERC20ProxyContract> {
+        if (!_.isUndefined(this._erc20ProxyContractIfExists)) {
+            return this._erc20ProxyContractIfExists;
+        }
+        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
+            artifacts.ERC20Proxy,
+            this._contractAddressIfExists,
+        );
+        const contractInstance = new ERC20ProxyContract(
+            abi,
+            address,
+            this._web3Wrapper.getProvider(),
+            this._web3Wrapper.getContractDefaults(),
+        );
+        this._erc20ProxyContractIfExists = contractInstance;
+        return this._erc20ProxyContractIfExists;
+    }
+}