fix: re-allow unknown tokens to be queried in the swap/quote endpoint (…

…#226)

src/utils/token_metadata_utils.ts

@@ -11,7 +11,7 @@ import { ChainId, TokenMetadata } from '../types';
  */
 export function getTokenMetadataIfExists(tokenAddressOrSymbol: string, chainId: ChainId): TokenMetadata | undefined {
     let entry: TokenMetadataAndChainAddresses | undefined;
-    if (tokenAddressOrSymbol.startsWith('0x') && tokenAddressOrSymbol.length === ADDRESS_HEX_LENGTH) {
+    if (isTokenAddress(tokenAddressOrSymbol)) {
         entry = TokenMetadatasForChains.find(
             tm => tm.tokenAddresses[chainId].toLowerCase() === tokenAddressOrSymbol.toLowerCase(),
         );
@@ -59,6 +59,9 @@ export function isWETHSymbolOrAddress(tokenAddressOrSymbol: string, chainId: num
  * @param chainId the Network where the address should be hosted on.
  */
 export function findTokenAddressOrThrow(symbolOrAddress: string, chainId: ChainId): string {
+    if (isTokenAddress(symbolOrAddress)) {
+        return symbolOrAddress;
+    }
     const entry = getTokenMetadataIfExists(symbolOrAddress, chainId);
     if (!entry) {
         // NOTE(jalextowle): Use the original symbol to increase readability.
@@ -67,6 +70,15 @@ export function findTokenAddressOrThrow(symbolOrAddress: string, chainId: ChainI
     return entry.tokenAddress;
 }
 
+/**
+ * Returns whether a string is an address or not.
+ *
+ * @param symbolOrAddress the uppercase symbol of the token (ex. `REP`) or the address of the contract
+ */
+export function isTokenAddress(symbolOrAddress: string): boolean {
+    return symbolOrAddress.startsWith('0x') && symbolOrAddress.length === ADDRESS_HEX_LENGTH;
+}
+
 /**
  * Attempts to find the address of the token and throws if not found
  *

test/constants.ts

@@ -12,6 +12,8 @@ export const ZRX_TOKEN_ADDRESS = CONTRACT_ADDRESSES.zrxToken;
 export const WETH_TOKEN_ADDRESS = CONTRACT_ADDRESSES.etherToken;
 export const ZRX_ASSET_DATA = assetDataUtils.encodeERC20AssetData(ZRX_TOKEN_ADDRESS);
 export const WETH_ASSET_DATA = assetDataUtils.encodeERC20AssetData(WETH_TOKEN_ADDRESS);
+export const UNKNOWN_TOKEN_ADDRESS = '0xbe0037eaf2d64fe5529bca93c18c9702d3930376';
+export const UNKNOWN_TOKEN_ASSET_DATA = assetDataUtils.encodeERC20AssetData(UNKNOWN_TOKEN_ADDRESS);
 export const SYMBOL_TO_ADDRESS: ObjectMap<string> = {
     ZRX: ZRX_TOKEN_ADDRESS,
     WETH: WETH_TOKEN_ADDRESS,

test/swap_test.ts

@@ -16,6 +16,8 @@ import {
     CONTRACT_ADDRESSES,
     MAX_MINT_AMOUNT,
     SYMBOL_TO_ADDRESS,
+    UNKNOWN_TOKEN_ADDRESS,
+    UNKNOWN_TOKEN_ASSET_DATA,
     WETH_ASSET_DATA,
     WETH_TOKEN_ADDRESS,
     ZRX_ASSET_DATA,
@@ -92,6 +94,12 @@ describe(SUITE_NAME, () => {
                 makerAssetAmount: MAKER_WETH_AMOUNT,
                 takerAssetAmount: ONE_THOUSAND_IN_BASE,
             },
+            {
+                makerAssetData: ZRX_ASSET_DATA,
+                takerAssetData: UNKNOWN_TOKEN_ASSET_DATA,
+                makerAssetAmount: ONE_THOUSAND_IN_BASE,
+                takerAssetAmount: ONE_THOUSAND_IN_BASE,
+            },
         ]);
     });
     after(async () => {
@@ -121,6 +129,7 @@ describe(SUITE_NAME, () => {
                 { buyToken: 'WETH', sellToken: 'ZRX', buyAmount: '1000' },
                 { buyToken: ZRX_TOKEN_ADDRESS, sellToken: 'WETH', buyAmount: '1000' },
                 { buyToken: ZRX_TOKEN_ADDRESS, sellToken: WETH_TOKEN_ADDRESS, buyAmount: '1000' },
+                { buyToken: 'ZRX', sellToken: UNKNOWN_TOKEN_ADDRESS, buyAmount: '1000' },
             ];
             for (const parameters of parameterPermutations) {
                 it(`should return a valid quote with ${JSON.stringify(parameters)}`, async () => {