@0x/asset-swapper: Guess deployment nonce from transformer address.

`@0x/asset-swapper`: Fix ETH not being passed as the token to `transformERC20()`.
2020-06-09 13:38:04 -04:00
parent f1f6aa7d80
commit 7b298939e2
3 changed files with 99 additions and 26 deletions
--- a/packages/asset-swapper/package.json
+++ b/packages/asset-swapper/package.json
@@ -57,6 +57,7 @@
        "@0x/web3-wrapper": "^7.0.7",
        "axios": "^0.19.2",
        "axios-mock-adapter": "^1.18.1",
+        "ethereumjs-util": "^5.1.1",
        "heartbeats": "^5.0.1",
        "lodash": "^4.17.11"
    },
--- a/packages/asset-swapper/src/quote_consumers/exchange_proxy_swap_quote_consumer.ts
+++ b/packages/asset-swapper/src/quote_consumers/exchange_proxy_swap_quote_consumer.ts
@@ -11,6 +11,7 @@ import { assetDataUtils, ERC20AssetData } from '@0x/order-utils';
 import { AssetProxyId } from '@0x/types';
 import { BigNumber, providerUtils } from '@0x/utils';
 import { SupportedProvider, ZeroExProvider } from '@0x/web3-wrapper';
+import * as ethjs from 'ethereumjs-util';
 import * as _ from 'lodash';

 import { constants } from '../constants';
@@ -30,10 +31,17 @@ import { assert } from '../utils/assert';

 // tslint:disable-next-line:custom-no-magic-numbers
 const MAX_UINT256 = new BigNumber(2).pow(256).minus(1);
+const { NULL_ADDRESS } = constants;
+const MAX_NONCE_GUESSES = 2048;

 export class ExchangeProxySwapQuoteConsumer implements SwapQuoteConsumerBase {
    public readonly provider: ZeroExProvider;
    public readonly chainId: number;
+    public readonly transformerNonces: {
+        wethTransformer: number;
+        payTakerTransformer: number;
+        fillQuoteTransformer: number;
+    };

    private readonly _transformFeature: ITransformERC20Contract;

@@ -49,6 +57,20 @@ export class ExchangeProxySwapQuoteConsumer implements SwapQuoteConsumerBase {
        this.chainId = chainId;
        this.contractAddresses = contractAddresses;
        this._transformFeature = new ITransformERC20Contract(contractAddresses.exchangeProxy, supportedProvider);
+        this.transformerNonces = {
+            wethTransformer: findTransformerNonce(
+                contractAddresses.transformers.wethTransformer,
+                contractAddresses.exchangeProxyTransformerDeployer,
+            ),
+            payTakerTransformer: findTransformerNonce(
+                contractAddresses.transformers.payTakerTransformer,
+                contractAddresses.exchangeProxyTransformerDeployer,
+            ),
+            fillQuoteTransformer: findTransformerNonce(
+                contractAddresses.transformers.fillQuoteTransformer,
+                contractAddresses.exchangeProxyTransformerDeployer,
+            ),
+        };
    }

    public async getCalldataOrThrowAsync(
@@ -56,24 +78,24 @@ export class ExchangeProxySwapQuoteConsumer implements SwapQuoteConsumerBase {
        opts: Partial<SwapQuoteGetOutputOpts> = {},
    ): Promise<CalldataInfo> {
        assert.isValidSwapQuote('quote', quote);
-        const exchangeProxyOpts = {
+        const { isFromETH, isToETH } = {
            ...constants.DEFAULT_FORWARDER_SWAP_QUOTE_GET_OPTS,
-            ...{
+            extensionContractOpts: {
                isFromETH: false,
                isToETH: false,
            },
            ...opts,
-        }.extensionContractOpts as ExchangeProxyContractOpts;
+        }.extensionContractOpts;

        const sellToken = getTokenFromAssetData(quote.takerAssetData);
        const buyToken = getTokenFromAssetData(quote.makerAssetData);

        // Build up the transforms.
        const transforms = [];
-        if (exchangeProxyOpts.isFromETH) {
+        if (isFromETH) {
            // Create a WETH wrapper if coming from ETH.
            transforms.push({
-                transformer: this.contractAddresses.transformers.wethTransformer,
+                deploymentNonce: this.transformerNonces.wethTransformer,
                data: encodeWethTransformerData({
                    token: ETH_TOKEN_ADDRESS,
                    amount: quote.worstCaseQuoteInfo.totalTakerAssetAmount,
@@ -83,7 +105,7 @@ export class ExchangeProxySwapQuoteConsumer implements SwapQuoteConsumerBase {

        // This transformer will fill the quote.
        transforms.push({
-            transformer: this.contractAddresses.transformers.fillQuoteTransformer,
+            deploymentNonce: this.transformerNonces.fillQuoteTransformer,
            data: encodeFillQuoteTransformerData({
                sellToken,
                buyToken,
@@ -95,10 +117,10 @@ export class ExchangeProxySwapQuoteConsumer implements SwapQuoteConsumerBase {
            }),
        });

-        if (exchangeProxyOpts.isToETH) {
+        if (isToETH) {
            // Create a WETH unwrapper if going to ETH.
            transforms.push({
-                transformer: this.contractAddresses.transformers.wethTransformer,
+                deploymentNonce: this.transformerNonces.wethTransformer,
                data: encodeWethTransformerData({
                    token: this.contractAddresses.etherToken,
                    amount: MAX_UINT256,
@@ -108,7 +130,7 @@ export class ExchangeProxySwapQuoteConsumer implements SwapQuoteConsumerBase {

        // The final transformer will send all funds to the taker.
        transforms.push({
-            transformer: this.contractAddresses.transformers.payTakerTransformer,
+            deploymentNonce: this.transformerNonces.payTakerTransformer,
            data: encodePayTakerTransformerData({
                tokens: [sellToken, buyToken, ETH_TOKEN_ADDRESS],
                amounts: [],
@@ -117,8 +139,8 @@ export class ExchangeProxySwapQuoteConsumer implements SwapQuoteConsumerBase {

        const calldataHexString = this._transformFeature
            .transformERC20(
-                sellToken,
-                buyToken,
+                isFromETH ? ETH_TOKEN_ADDRESS : sellToken,
+                isToETH ? ETH_TOKEN_ADDRESS : buyToken,
                quote.worstCaseQuoteInfo.totalTakerAssetAmount,
                quote.worstCaseQuoteInfo.makerAssetAmount,
                transforms,
@@ -126,7 +148,7 @@ export class ExchangeProxySwapQuoteConsumer implements SwapQuoteConsumerBase {
            .getABIEncodedTransactionData();

        let ethAmount = quote.worstCaseQuoteInfo.protocolFeeInWeiAmount;
-        if (exchangeProxyOpts.isFromETH) {
+        if (isFromETH) {
            ethAmount = ethAmount.plus(quote.worstCaseQuoteInfo.takerAssetAmount);
        }

@@ -159,3 +181,32 @@ function getTokenFromAssetData(assetData: string): string {
    // tslint:disable-next-line:no-unnecessary-type-assertion
    return (data as ERC20AssetData).tokenAddress;
 }
+
+/**
+ * Find the nonce for a transformer given its deployer.
+ * If `deployer` is the null address, zero will always be returned.
+ */
+export function findTransformerNonce(transformer: string, deployer: string = NULL_ADDRESS): number {
+    if (deployer === NULL_ADDRESS) {
+        return 0;
+    }
+    const lowercaseTransformer = transformer.toLowerCase();
+    // Try to guess the nonce.
+    for (let nonce = 0; nonce < MAX_NONCE_GUESSES; ++nonce) {
+        const deployedAddress = getTransformerAddress(deployer, nonce);
+        if (deployedAddress === lowercaseTransformer) {
+            return nonce;
+        }
+    }
+    throw new Error(`${deployer} did not deploy ${transformer}!`);
+}
+
+/**
+ * Compute the deployed address for a transformer given a deployer and nonce.
+ */
+export function getTransformerAddress(deployer: string, nonce: number): string {
+    return ethjs.bufferToHex(
+        // tslint:disable-next-line: custom-no-magic-numbers
+        ethjs.rlphash([deployer, nonce] as any).slice(12),
+    );
+}
--- a/packages/asset-swapper/test/exchange_proxy_swap_quote_consumer_test.ts
+++ b/packages/asset-swapper/test/exchange_proxy_swap_quote_consumer_test.ts
@@ -15,7 +15,10 @@ import * as _ from 'lodash';
 import 'mocha';

 import { constants } from '../src/constants';
-import { ExchangeProxySwapQuoteConsumer } from '../src/quote_consumers/exchange_proxy_swap_quote_consumer';
+import {
+    ExchangeProxySwapQuoteConsumer,
+    getTransformerAddress,
+} from '../src/quote_consumers/exchange_proxy_swap_quote_consumer';
 import { MarketBuySwapQuote, MarketOperation, MarketSellSwapQuote } from '../src/types';
 import { OptimizedMarketOrder } from '../src/utils/market_operation_utils/types';

@@ -33,14 +36,16 @@ describe('ExchangeProxySwapQuoteConsumer', () => {
    const CHAIN_ID = 1;
    const TAKER_TOKEN = randomAddress();
    const MAKER_TOKEN = randomAddress();
+    const TRANSFORMER_DEPLOYER = randomAddress();
    const contractAddresses = {
        ...getContractAddressesForChainOrThrow(CHAIN_ID),
        exchangeProxy: randomAddress(),
        exchangeProxyAllowanceTarget: randomAddress(),
+        exchangeProxyTransformerDeployer: TRANSFORMER_DEPLOYER,
        transformers: {
-            wethTransformer: randomAddress(),
-            payTakerTransformer: randomAddress(),
-            fillQuoteTransformer: randomAddress(),
+            wethTransformer: getTransformerAddress(TRANSFORMER_DEPLOYER, 1),
+            payTakerTransformer: getTransformerAddress(TRANSFORMER_DEPLOYER, 2),
+            fillQuoteTransformer: getTransformerAddress(TRANSFORMER_DEPLOYER, 3),
        },
    };
    let consumer: ExchangeProxySwapQuoteConsumer;
@@ -150,7 +155,7 @@ describe('ExchangeProxySwapQuoteConsumer', () => {
        {
            type: 'tuple[]',
            name: 'transformations',
-            components: [{ type: 'address', name: 'transformer' }, { type: 'bytes', name: 'data' }],
+            components: [{ type: 'uint32', name: 'deploymentNonce' }, { type: 'bytes', name: 'data' }],
        },
    ]);

@@ -160,7 +165,7 @@ describe('ExchangeProxySwapQuoteConsumer', () => {
        inputTokenAmount: BigNumber;
        minOutputTokenAmount: BigNumber;
        transformations: Array<{
-            transformer: string;
+            deploymentNonce: BigNumber;
            data: string;
        }>;
    }
@@ -175,8 +180,14 @@ describe('ExchangeProxySwapQuoteConsumer', () => {
            expect(callArgs.inputTokenAmount).to.bignumber.eq(quote.worstCaseQuoteInfo.totalTakerAssetAmount);
            expect(callArgs.minOutputTokenAmount).to.bignumber.eq(quote.worstCaseQuoteInfo.makerAssetAmount);
            expect(callArgs.transformations).to.be.length(2);
-            expect(callArgs.transformations[0].transformer === contractAddresses.transformers.fillQuoteTransformer);
-            expect(callArgs.transformations[1].transformer === contractAddresses.transformers.payTakerTransformer);
+            expect(
+                callArgs.transformations[0].deploymentNonce.toNumber() ===
+                    consumer.transformerNonces.fillQuoteTransformer,
+            );
+            expect(
+                callArgs.transformations[1].deploymentNonce.toNumber() ===
+                    consumer.transformerNonces.payTakerTransformer,
+            );
            const fillQuoteTransformerData = decodeFillQuoteTransformerData(callArgs.transformations[0].data);
            expect(fillQuoteTransformerData.side).to.eq(FillQuoteTransformerSide.Sell);
            expect(fillQuoteTransformerData.fillAmount).to.bignumber.eq(quote.takerAssetFillAmount);
@@ -198,8 +209,14 @@ describe('ExchangeProxySwapQuoteConsumer', () => {
            expect(callArgs.inputTokenAmount).to.bignumber.eq(quote.worstCaseQuoteInfo.totalTakerAssetAmount);
            expect(callArgs.minOutputTokenAmount).to.bignumber.eq(quote.worstCaseQuoteInfo.makerAssetAmount);
            expect(callArgs.transformations).to.be.length(2);
-            expect(callArgs.transformations[0].transformer === contractAddresses.transformers.fillQuoteTransformer);
-            expect(callArgs.transformations[1].transformer === contractAddresses.transformers.payTakerTransformer);
+            expect(
+                callArgs.transformations[0].deploymentNonce.toNumber() ===
+                    consumer.transformerNonces.fillQuoteTransformer,
+            );
+            expect(
+                callArgs.transformations[1].deploymentNonce.toNumber() ===
+                    consumer.transformerNonces.payTakerTransformer,
+            );
            const fillQuoteTransformerData = decodeFillQuoteTransformerData(callArgs.transformations[0].data);
            expect(fillQuoteTransformerData.side).to.eq(FillQuoteTransformerSide.Buy);
            expect(fillQuoteTransformerData.fillAmount).to.bignumber.eq(quote.makerAssetFillAmount);
@@ -216,8 +233,8 @@ describe('ExchangeProxySwapQuoteConsumer', () => {
            const quote = getRandomSellQuote();
            const callInfo = await consumer.getCalldataOrThrowAsync(quote);
            const callArgs = callDataEncoder.decode(callInfo.calldataHexString) as CallArgs;
-            const transformers = callArgs.transformations.map(t => t.transformer);
-            expect(transformers).to.not.include(contractAddresses.transformers.wethTransformer);
+            const nonces = callArgs.transformations.map(t => t.deploymentNonce);
+            expect(nonces).to.not.include(consumer.transformerNonces.wethTransformer);
        });

        it('ETH -> ERC20 has a WETH transformer before the fill', async () => {
@@ -226,7 +243,9 @@ describe('ExchangeProxySwapQuoteConsumer', () => {
                extensionContractOpts: { isFromETH: true },
            });
            const callArgs = callDataEncoder.decode(callInfo.calldataHexString) as CallArgs;
-            expect(callArgs.transformations[0].transformer).to.eq(contractAddresses.transformers.wethTransformer);
+            expect(callArgs.transformations[0].deploymentNonce.toNumber()).to.eq(
+                consumer.transformerNonces.wethTransformer,
+            );
            const wethTransformerData = decodeWethTransformerData(callArgs.transformations[0].data);
            expect(wethTransformerData.amount).to.bignumber.eq(quote.worstCaseQuoteInfo.totalTakerAssetAmount);
            expect(wethTransformerData.token).to.eq(ETH_TOKEN_ADDRESS);
@@ -238,7 +257,9 @@ describe('ExchangeProxySwapQuoteConsumer', () => {
                extensionContractOpts: { isToETH: true },
            });
            const callArgs = callDataEncoder.decode(callInfo.calldataHexString) as CallArgs;
-            expect(callArgs.transformations[1].transformer).to.eq(contractAddresses.transformers.wethTransformer);
+            expect(callArgs.transformations[1].deploymentNonce.toNumber()).to.eq(
+                consumer.transformerNonces.wethTransformer,
+            );
            const wethTransformerData = decodeWethTransformerData(callArgs.transformations[1].data);
            expect(wethTransformerData.amount).to.bignumber.eq(MAX_UINT256);
            expect(wethTransformerData.token).to.eq(contractAddresses.etherToken);