feat: add oracle price fallback for custom-priced tokens

src/external-api.ts

@@ -209,3 +209,36 @@ const _assembleTxOdosMemoized = memoize(
 export async function _assembleTxOdos(this: Llamalend, pathId: string): Promise<string> {
     return _assembleTxOdosMemoized(this.constants.ALIASES.leverage_zap, pathId);
 }
+
+export const _getOraclePricesFromApi = memoize(
+    async (network: INetworkName): Promise<IDict<number>> => {
+        const url = `https://prices.curve.finance/v1/lending/markets/${network}`;
+        const response = await fetch(url);
+        if (response.status !== 200) {
+            return {};
+        }
+
+        const { data } = await response.json() as { data: Array<{
+            controller: string,
+            collateral_token: {
+                symbol: string,
+                address: string
+            },
+            price_oracle: number
+        }> };
+
+        const oraclePrices: IDict<number> = {};
+
+        for (const market of data) {
+            if (market.price_oracle && market.collateral_token && market.collateral_token.address) {
+                oraclePrices[market.collateral_token.address.toLowerCase()] = market.price_oracle;
+            }
+        }
+
+        return oraclePrices;
+    },
+    {
+        promise: true,
+        maxAge: 60 * 1000,
+    }
+);

src/utils.ts

@@ -2,7 +2,7 @@ import { ethers,  BigNumberish, Numeric } from "ethers";
 import { Call } from "@curvefi/ethcall";
 import BigNumber from 'bignumber.js';
 import { ICurveContract, IDict, TGas } from "./interfaces.js";
-import { _getUsdPricesFromApi } from "./external-api.js";
+import { _getUsdPricesFromApi, _getOraclePricesFromApi } from "./external-api.js";
 import type { Llamalend } from "./llamalend.js";
 import { JsonFragment } from "ethers/lib.esm";
 import { L2Networks } from "./constants/L2Networks.js";
@@ -370,6 +370,23 @@ export const _getUsdRate = async function (this: Llamalend, assetId: string): Pr
         }
     }
 
+    if (_usdRatesCache[assetId]['rate'] === 0) {
+        const originalAssetId = arguments[0];
+        const oraclePrices = await _getOraclePricesFromApi.call(this, this.constants.NETWORK_NAME);
+
+        if (originalAssetId.toLowerCase() in oraclePrices) {
+            const oraclePriceInCrvUsd = oraclePrices[originalAssetId.toLowerCase()];
+
+            if (oraclePriceInCrvUsd > 0) {
+                const crvUsdAddress = this.constants.ALIASES.crvUSD;
+                const crvUsdPrice = assetId.toLowerCase() === crvUsdAddress.toLowerCase() ? 1 :
+                    await _getUsdRate.call(this, crvUsdAddress);
+
+                _usdRatesCache[assetId] = {'rate': oraclePriceInCrvUsd * crvUsdPrice, 'time': Date.now()};
+            }
+        }
+    }
+
     return _usdRatesCache[assetId]['rate']
 }