1 files changed, 87 insertions, 0 deletions
diff --git a/packages/0x.js/src/contract_wrappers/ether_token_wrapper.ts b/packages/0x.js/src/contract_wrappers/ether_token_wrapper.ts
new file mode 100644
index 000000000..3cd2f0224
--- /dev/null
+++ b/packages/0x.js/src/contract_wrappers/ether_token_wrapper.ts
@@ -0,0 +1,87 @@
+import * as _ from 'lodash';
+import BigNumber from 'bignumber.js';
+import {Web3Wrapper} from '../web3_wrapper';
+import {ContractWrapper} from './contract_wrapper';
+import {TokenWrapper} from './token_wrapper';
+import {EtherTokenContract, ZeroExError} from '../types';
+import {assert} from '../utils/assert';
+import {artifacts} from '../artifacts';
+
+/**
+ * This class includes all the functionality related to interacting with a wrapped Ether ERC20 token contract.
+ * The caller can convert ETH into the equivalent number of wrapped ETH ERC20 tokens and back.
+ */
+export class EtherTokenWrapper extends ContractWrapper {
+    private _etherTokenContractIfExists?: EtherTokenContract;
+    private _tokenWrapper: TokenWrapper;
+    private _contractAddressIfExists?: string;
+    constructor(web3Wrapper: Web3Wrapper, tokenWrapper: TokenWrapper, contractAddressIfExists?: string) {
+        super(web3Wrapper);
+        this._tokenWrapper = tokenWrapper;
+        this._contractAddressIfExists = contractAddressIfExists;
+    }
+    /**
+     * Deposit ETH into the Wrapped ETH smart contract and issues the equivalent number of wrapped ETH tokens
+     * to the depositor address. These wrapped ETH tokens can be used in 0x trades and are redeemable for 1-to-1
+     * for ETH.
+     * @param   amountInWei      Amount of ETH in Wei the caller wishes to deposit.
+     * @param   depositor   The hex encoded user Ethereum address that would like to make the deposit.
+     * @return Transaction hash.
+     */
+    public async depositAsync(amountInWei: BigNumber, depositor: string): Promise<string> {
+        assert.isValidBaseUnitAmount('amountInWei', amountInWei);
+        await assert.isSenderAddressAsync('depositor', depositor, this._web3Wrapper);
+
+        const ethBalanceInWei = await this._web3Wrapper.getBalanceInWeiAsync(depositor);
+        assert.assert(ethBalanceInWei.gte(amountInWei), ZeroExError.InsufficientEthBalanceForDeposit);
+
+        const wethContract = await this._getEtherTokenContractAsync();
+        const txHash = await wethContract.deposit.sendTransactionAsync({
+            from: depositor,
+            value: amountInWei,
+        });
+        return txHash;
+    }
+    /**
+     * Withdraw ETH to the withdrawer's address from the wrapped ETH smart contract in exchange for the
+     * equivalent number of wrapped ETH tokens.
+     * @param   amountInWei  Amount of ETH in Wei the caller wishes to withdraw.
+     * @param   withdrawer   The hex encoded user Ethereum address that would like to make the withdrawl.
+     * @return Transaction hash.
+     */
+    public async withdrawAsync(amountInWei: BigNumber, withdrawer: string): Promise<string> {
+        assert.isValidBaseUnitAmount('amountInWei', amountInWei);
+        await assert.isSenderAddressAsync('withdrawer', withdrawer, this._web3Wrapper);
+
+        const wethContractAddress = await this.getContractAddressAsync();
+        const WETHBalanceInBaseUnits = await this._tokenWrapper.getBalanceAsync(wethContractAddress, withdrawer);
+        assert.assert(WETHBalanceInBaseUnits.gte(amountInWei), ZeroExError.InsufficientWEthBalanceForWithdrawal);
+
+        const wethContract = await this._getEtherTokenContractAsync();
+        const txHash = await wethContract.withdraw.sendTransactionAsync(amountInWei, {
+            from: withdrawer,
+        });
+        return txHash;
+    }
+    /**
+     * Retrieves the Wrapped Ether token contract address
+     * @return  The Wrapped Ether token contract address
+     */
+    public async getContractAddressAsync(): Promise<string> {
+        const wethContract = await this._getEtherTokenContractAsync();
+        return wethContract.address;
+    }
+    private _invalidateContractInstance(): void {
+        delete this._etherTokenContractIfExists;
+    }
+    private async _getEtherTokenContractAsync(): Promise<EtherTokenContract> {
+        if (!_.isUndefined(this._etherTokenContractIfExists)) {
+            return this._etherTokenContractIfExists;
+        }
+        const contractInstance = await this._instantiateContractIfExistsAsync<EtherTokenContract>(
+            artifacts.EtherTokenArtifact, this._contractAddressIfExists,
+        );
+        this._etherTokenContractIfExists = contractInstance as EtherTokenContract;
+        return this._etherTokenContractIfExists;
+    }
+}