fix: moved eth address logic to zapper service, fixed some oracle logic

src/helpers.ts

@@ -4,6 +4,7 @@ import { Integer, SdkError, Usdc } from "./types";
 
 export const ZeroAddress = "0x0000000000000000000000000000000000000000";
 export const EthAddress = "0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE";
+export const WethAddress = "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2";
 
 // handle a non-200 `fetch` response.
 export async function handleHttpError(response: Response): Promise<Response> {

src/interfaces/vault.ts

@@ -4,7 +4,7 @@ import BigNumber from "bignumber.js";
 
 import { ChainId } from "../chain";
 import { ServiceInterface } from "../common";
-import { EthAddress, ZeroAddress } from "../helpers";
+import { EthAddress } from "../helpers";
 import {
   Address,
   Balance,
@@ -185,27 +185,23 @@ export class VaultInterface<T extends ChainId> extends ServiceInterface<T> {
       const gasPrice = await this.yearn.services.zapper.gas();
       const gasPriceFastGwei = new BigNumber(gasPrice.fast).times(new BigNumber(10 ** 9));
 
-      let sellToken = token;
-      if (EthAddress === token) {
-        // If Ether is being sent, the sellTokenAddress should be the zero address
-        sellToken = ZeroAddress;
-      }
-
       const zapInParams = await this.yearn.services.zapper.zapIn(
         account,
-        sellToken,
+        token,
         amount,
         vault,
         gasPriceFastGwei.toString(),
         options.slippage
       );
 
+      const valueBigNumber = new BigNumber(zapInParams.value);
+
       const transaction: TransactionRequest = {
         to: zapInParams.to,
         from: zapInParams.from,
         gasPrice: zapInParams.gasPrice,
-        data: zapInParams.data as string,
-        value: zapInParams.value as string
+        data: zapInParams.data,
+        value: valueBigNumber.toFixed(0)
       };
 
       return signer.sendTransaction(transaction);
@@ -243,15 +239,9 @@ export class VaultInterface<T extends ChainId> extends ServiceInterface<T> {
       const gasPrice = await this.yearn.services.zapper.gas();
       const gasPriceFastGwei = new BigNumber(gasPrice.fast).times(new BigNumber(10 ** 9));
 
-      let toToken = token;
-      if (EthAddress === token) {
-        // If Ether is being received, the toTokenAddress should be the zero address
-        toToken = ZeroAddress;
-      }
-
       const zapOutParams = await this.yearn.services.zapper.zapOut(
         account,
-        toToken,
+        token,
         amount,
         vault,
         gasPriceFastGwei.toString(),
@@ -262,8 +252,8 @@ export class VaultInterface<T extends ChainId> extends ServiceInterface<T> {
         to: zapOutParams.to,
         from: zapOutParams.from,
         gasPrice: zapOutParams.gasPrice,
-        data: zapOutParams.data as string,
-        value: zapOutParams.value as string
+        data: zapOutParams.data,
+        value: zapOutParams.value
       };
 
       return signer.sendTransaction(transaction);

src/services/simulation.ts

@@ -5,6 +5,7 @@ import BigNumber from "bignumber.js";
 import { ChainId } from "../chain";
 import { Service } from "../common";
 import { Context } from "../context";
+import { EthAddress, WethAddress } from "../helpers";
 import { Address, Integer, SdkError } from "../types";
 import { TransactionOutcome } from "../types/custom/simulation";
 import { OracleService } from "./oracle";
@@ -219,23 +220,22 @@ async function zapIn(
     to: zapInParams.to,
     gas: gasLimit,
     simulation_type: "quick",
-    gas_price: "0",
     value: value,
     save: true
   };
 
   const simulationResponse: SimulationResponse = await makeRequest(`${baseUrl}/simulate`, body);
-  const assetTokensReceived = simulationResponse.transaction.transaction_info.call_trace.output;
+  const assetTokensReceived = new BigNumber(simulationResponse.transaction.transaction_info.call_trace.output);
   const pricePerShare = await vaultContract.pricePerShare();
-  const targetUnderlyingTokensReceived = new BigNumber(assetTokensReceived)
+  const targetUnderlyingTokensReceived = assetTokensReceived
     .times(new BigNumber(pricePerShare.toString()))
     .div(new BigNumber(10).pow(18))
     .toFixed(0);
 
   const oracle = new OracleService(chainId, ctx);
 
-  const zapInAmountUsdc = await oracle.getNormalizedValueUsdc(token, assetTokensReceived);
-  const boughtAssetAmountUsdc = await oracle.getNormalizedValueUsdc(vault, amount);
+  const zapInAmountUsdc = await oracle.getNormalizedValueUsdc(token === EthAddress ? WethAddress : token, amount);
+  const boughtAssetAmountUsdc = await oracle.getNormalizedValueUsdc(vault, assetTokensReceived.toFixed(0));
 
   const conversionRate = new BigNumber(boughtAssetAmountUsdc).div(new BigNumber(zapInAmountUsdc)).toNumber();
   const slippage = 1 - conversionRate;
@@ -244,7 +244,7 @@ async function zapIn(
     sourceTokenAddress: token,
     sourceTokenAmount: amount,
     targetTokenAddress: zapInParams.buyTokenAddress,
-    targetTokenAmount: assetTokensReceived,
+    targetTokenAmount: assetTokensReceived.toFixed(0),
     targetUnderlyingTokenAddress: underlyingTokenAddress,
     targetUnderlyingTokenAmount: targetUnderlyingTokensReceived,
     conversionRate: conversionRate,
@@ -327,8 +327,8 @@ async function zapOut(
 
   const oracle = new OracleService(chainId, ctx);
 
-  const zapOutAmountUsdc = await oracle.getNormalizedValueUsdc(token, output);
   const soldAssetAmountUsdc = await oracle.getNormalizedValueUsdc(vault, amount);
+  const zapOutAmountUsdc = await oracle.getNormalizedValueUsdc(token === EthAddress ? WethAddress : token, output);
 
   const conversionRate = new BigNumber(zapOutAmountUsdc).div(new BigNumber(soldAssetAmountUsdc)).toNumber();
   const slippage = 1 - conversionRate;

src/services/zapper.ts

@@ -125,17 +125,24 @@ export class ZapperService extends Service {
     gasPrice: Integer,
     slippagePercentage: number
   ): Promise<ZapInOutput> {
+    let sellToken = token;
+    if (EthAddress === token) {
+      // If Ether is being sent, the sellTokenAddress should be the zero address
+      sellToken = ZeroAddress;
+    }
+
     const url = "https://api.zapper.fi/v1/zap-in/yearn/transaction";
     const params = new URLSearchParams({
       ownerAddress: from,
-      sellTokenAddress: token,
+      sellTokenAddress: sellToken,
       sellAmount: amount,
       poolAddress: vault,
       gasPrice: gasPrice,
       slippagePercentage: slippagePercentage.toString(),
       api_key: this.ctx.zapper,
       skipGasEstimate: "true"
     });
+
     const response: ZapInOutput = await fetch(`${url}?${params}`)
       .then(handleHttpError)
       .then(res => res.json());
@@ -160,10 +167,16 @@ export class ZapperService extends Service {
     gasPrice: Integer,
     slippagePercentage: number
   ): Promise<ZapOutOutput> {
+    let toToken = token;
+    if (EthAddress === token) {
+      // If Ether is being received, the toTokenAddress should be the zero address
+      toToken = ZeroAddress;
+    }
+
     const url = "https://api.zapper.fi/v1/zap-out/yearn/transaction";
     const params = new URLSearchParams({
       ownerAddress: from,
-      toTokenAddress: token,
+      toTokenAddress: toToken,
       sellAmount: amount,
       poolAddress: vault,
       gasPrice: gasPrice,