fix: incorrect token information in response for wetheth (#1867)

Author: NikolasHaimerl

api/_utils.ts

@@ -562,6 +562,15 @@ export const getTokenByAddress = (
       }
     }
 
+    // For some chains, the same address is associated with both the ETH and WETH symbols in the constants file.
+    // See: https://www.npmjs.com/package/@across-protocol/constants
+    // This can cause issues when resolving the token.
+    // To fix this, we will check if there is a WETH match and prioritize it over the ETH match.
+    const wethMatch = matches.find(([symbol]) => symbol === "WETH");
+    if (wethMatch) {
+      return wethMatch[1];
+    }
+
     return matches[0][1];
   } catch (error) {
     return undefined;
@@ -2543,12 +2552,7 @@ export async function getTokenInfo({ chainId, address }: TokenOptions): Promise<
       });
     }
 
-    // Resolve token info statically
-    const token = Object.values(TOKEN_SYMBOLS_MAP).find((token) =>
-      Boolean(
-        token.addresses?.[chainId]?.toLowerCase() === address.toLowerCase()
-      )
-    );
+    const token = getTokenByAddress(address, chainId);
 
     if (token) {
       return {

e2e-api/swap/fetch-approval.test.ts

@@ -165,4 +165,24 @@ describe("GET /swap/approval", () => {
       );
     });
   });
+
+  test("should return WETH for Base and Linea", async () => {
+    const params = {
+      tradeType: "exactInput",
+      amount: "10000000000000000",
+      inputToken: "0x4200000000000000000000000000000000000006",
+      outputToken: "0xe5D7C2a44FfDDf6b295A15c148167daaAf5Cf34f",
+      originChainId: 8453,
+      destinationChainId: 59144,
+      depositor: "0xB8034521BB1a343D556e5005680B3F17FFc74BeD",
+      recipient: "0xB8034521BB1a343D556e5005680B3F17FFc74BeD",
+      includeSources: "uniswap_v3",
+    };
+    const response = await axios.get(SWAP_API_URL, {
+      params,
+    });
+    expect(response.status).toBe(200);
+    expect(response.data.inputToken.symbol).toBe("WETH");
+    expect(response.data.outputToken.symbol).toBe("WETH");
+  });
 });

test/api/_utils.test.ts

@@ -7,6 +7,7 @@ import {
   validEvmAddress,
   validSvmAddress,
   validAddress,
+  getTokenByAddress,
 } from "../../api/_utils";
 import { is } from "superstruct";
 
@@ -109,6 +110,39 @@ describe("_utils", () => {
     });
   });
 
+  describe("#getTokenByAddress()", () => {
+    // Iterate over all chain IDs to test the token resolution for each chain.
+    for (const chainId of Object.values(CHAIN_IDs)) {
+      if (typeof chainId !== "number") continue;
+
+      const weth = TOKEN_SYMBOLS_MAP.WETH.addresses[chainId];
+      const eth = TOKEN_SYMBOLS_MAP.ETH.addresses[chainId];
+
+      // Test case where WETH and ETH have the same address.
+      // In this case, we want to ensure that WETH is always returned to avoid ambiguity.
+      if (weth && eth && weth.toLowerCase() === eth.toLowerCase()) {
+        test(`should return WETH for chain ${chainId} when both ETH and WETH have the same address`, () => {
+          const token = getTokenByAddress(weth, chainId);
+          expect(token?.symbol).toBe("WETH");
+        });
+      } else {
+        // Test case where WETH and ETH have different addresses.
+        if (weth) {
+          test(`should return WETH for chain ${chainId}`, () => {
+            const token = getTokenByAddress(weth, chainId);
+            expect(token?.symbol).toBe("WETH");
+          });
+        }
+        if (eth) {
+          test(`should return ETH for chain ${chainId}`, () => {
+            const token = getTokenByAddress(eth, chainId);
+            expect(token?.symbol).toBe("ETH");
+          });
+        }
+      }
+    }
+  });
+
   describe("#validateChainAndTokenParams()", () => {
     test("throw if 'destinationChainId' is not provided", () => {
       expect(() => validateChainAndTokenParams({})).toThrowError(