fix: gas price estimates for swaps (#1251)

Co-authored-by: Pano Skylakis <[email protected]>
immutable · Dec 6, 2023 · d8fd065 · d8fd065
1 parent ce3898b
commit d8fd065
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Showing 5 changed files with 101 additions and 87 deletions.
diff --git a/packages/internal/dex/sdk/src/exchange.getUnsignedSwapTxFromAmountIn.test.ts b/packages/internal/dex/sdk/src/exchange.getUnsignedSwapTxFromAmountIn.test.ts
@@ -41,6 +41,9 @@ import {
   TEST_FROM_ADDRESS,
   expectToBeString,
   decodeMulticallExactInputWithoutFees,
+  buildBlock,
+  TEST_MAX_PRIORITY_FEE_PER_GAS,
+  TEST_BASE_FEE,
 } from './test/utils';
 
 jest.mock('@ethersproject/providers');
@@ -58,7 +61,7 @@ jest.mock('./lib/utils', () => ({
 
 const HIGHER_SLIPPAGE = 0.2;
 const APPROVED_AMOUNT = newAmountFromString('1', USDC_TEST_TOKEN);
-const APPROVE_GAS_ESTIMATE = BigNumber.from('100000');
+const APPROVE_GAS_ESTIMATE = BigNumber.from('100000'); // gas units
 
 describe('getUnsignedSwapTxFromAmountIn', () => {
   let erc20Contract: jest.Mock<any, any, any>;
@@ -75,9 +78,14 @@ describe('getUnsignedSwapTxFromAmountIn', () => {
     })) as unknown as JsonRpcProvider;
 
     (JsonRpcBatchProvider as unknown as jest.Mock).mockImplementation(() => ({
-      getFeeData: async () => ({
-        maxFeePerGas: null,
-        gasPrice: TEST_GAS_PRICE,
+      getBlock: async () => buildBlock({ baseFeePerGas: BigNumber.from(TEST_BASE_FEE) }),
+      send: jest.fn().mockImplementation(async (method) => {
+        switch (method) {
+          case 'eth_maxPriorityFeePerGas':
+            return BigNumber.from(TEST_MAX_PRIORITY_FEE_PER_GAS);
+          default:
+            throw new Error('Method not implemented');
+        }
       }),
     })) as unknown as JsonRpcProvider;
   });

diff --git a/packages/internal/dex/sdk/src/exchange.getUnsignedSwapTxFromAmountOut.test.ts b/packages/internal/dex/sdk/src/exchange.getUnsignedSwapTxFromAmountOut.test.ts
@@ -11,7 +11,6 @@ import {
   setupSwapTxTest,
   TEST_ROUTER_ADDRESS,
   TEST_DEX_CONFIGURATION,
-  TEST_GAS_PRICE,
   TEST_FEE_RECIPIENT,
   TEST_SECONDARY_FEE_ADDRESS,
   decodeMulticallExactOutputSingleWithFees,
@@ -36,6 +35,9 @@ import {
   expectToBeString,
   refundETHFunctionSignature,
   NATIVE_TEST_TOKEN,
+  buildBlock,
+  TEST_BASE_FEE,
+  TEST_MAX_PRIORITY_FEE_PER_GAS,
 } from './test/utils';
 
 jest.mock('@ethersproject/providers');
@@ -68,9 +70,14 @@ describe('getUnsignedSwapTxFromAmountOut', () => {
     }));
 
     (JsonRpcBatchProvider as unknown as jest.Mock).mockImplementation(() => ({
-      getFeeData: async () => ({
-        maxFeePerGas: null,
-        gasPrice: TEST_GAS_PRICE,
+      getBlock: async () => buildBlock({ baseFeePerGas: BigNumber.from(TEST_BASE_FEE) }),
+      send: jest.fn().mockImplementation(async (method) => {
+        switch (method) {
+          case 'eth_maxPriorityFeePerGas':
+            return BigNumber.from(TEST_MAX_PRIORITY_FEE_PER_GAS); // 10 gwei
+          default:
+            throw new Error('Method not implemented');
+        }
       }),
     })) as unknown as JsonRpcProvider;
   });

diff --git a/packages/internal/dex/sdk/src/lib/transactionUtils/gas.test.ts b/packages/internal/dex/sdk/src/lib/transactionUtils/gas.test.ts
@@ -1,11 +1,9 @@
-import { JsonRpcProvider } from '@ethersproject/providers';
-import { BigNumber } from '@ethersproject/bignumber';
-import { expectToBeDefined, NATIVE_TEST_TOKEN, TEST_CHAIN_ID, TEST_RPC_URL } from 'test/utils';
+import { buildBlock, expectToBeDefined, formatAmount, NATIVE_TEST_TOKEN } from 'test/utils';
 import { newAmount } from 'lib/utils';
+import { BigNumber, providers } from 'ethers';
+import { IMMUTABLE_TESTNET_RPC_URL, IMMUTABLE_TESTNET_CHAIN_ID } from 'constants/chains';
 import { calculateGasFee, fetchGasPrice } from './gas';
 
-jest.mock('@ethersproject/providers');
-
 describe('calculateGasFee', () => {
   describe('when given a price and gas used', () => {
     it('calculates gas fee from gas used and gas price', async () => {
@@ -21,63 +19,41 @@ describe('calculateGasFee', () => {
 });
 
 describe('fetchGasPrice', () => {
-  describe('when no fee data is returned', () => {
-    it('should return null', async () => {
-      (JsonRpcProvider as unknown as jest.Mock).mockImplementation(() => ({
-        getFeeData: async () => ({
-          maxFeePerGas: null,
-          gasPrice: null,
-        }),
-      })) as unknown as JsonRpcProvider;
-
-      const provider = new JsonRpcProvider(TEST_RPC_URL, TEST_CHAIN_ID);
-
-      const gasFeeEstimate = await fetchGasPrice(provider, NATIVE_TEST_TOKEN);
-
-      expect(gasFeeEstimate).toBeNull();
+  describe.skip('for realsies', () => {
+    it('returns a gasPriceEstimate', async () => {
+      const provider = new providers.JsonRpcProvider(IMMUTABLE_TESTNET_RPC_URL, IMMUTABLE_TESTNET_CHAIN_ID);
+      const gasPriceEstimate = await fetchGasPrice(provider, NATIVE_TEST_TOKEN);
+      expectToBeDefined(gasPriceEstimate);
+      expect(formatAmount(gasPriceEstimate)).toEqual('0.000000010000000098');
     });
   });
 
-  describe('when EIP-1559 is not supported', () => {
-    it('should return the gasPrice', async () => {
-      const gasPrice = BigNumber.from('1500000000'); // 1.5 gwei or 1500000000 wei
-
-      (JsonRpcProvider as unknown as jest.Mock).mockImplementation(() => ({
-        getFeeData: async () => ({
-          maxFeePerGas: null,
-          gasPrice,
-        }),
-      })) as unknown as JsonRpcProvider;
-
-      const provider = new JsonRpcProvider(TEST_RPC_URL, TEST_CHAIN_ID);
-
-      const gasFeeEstimate = await fetchGasPrice(provider, NATIVE_TEST_TOKEN);
+  describe('when no fee data is returned', () => {
+    it('should return null', async () => {
+      const provider = {
+        getBlock: jest.fn().mockRejectedValue(new Error('failed to get block')),
+        send: jest.fn().mockRejectedValue(new Error('failed to get maxPriorityFeePerGas')),
+      };
 
-      expectToBeDefined(gasFeeEstimate);
-      expect(gasFeeEstimate.value.toString()).toEqual('1500000000');
-      expect(gasFeeEstimate.token.type).toEqual('native');
+      const gasPriceEstimate = await fetchGasPrice(provider, NATIVE_TEST_TOKEN);
+      expect(gasPriceEstimate).toBeNull();
     });
   });
 
   describe('when EIP-1559 is supported', () => {
     it('should return the maxFeePerGas', async () => {
-      const maxFeePerGas = BigNumber.from('2500000000'); // 2.5 gwei or 2500000000 wei
-      const maxPriorityFeePerGas = BigNumber.from('500000000'); // 0.5 gwei or 500000000 wei
-
-      (JsonRpcProvider as unknown as jest.Mock).mockImplementation(() => ({
-        getFeeData: async () => ({
-          maxFeePerGas,
-          maxPriorityFeePerGas,
-          gasPrice: null,
-        }),
-      })) as unknown as JsonRpcProvider;
-
-      const provider = new JsonRpcProvider(TEST_RPC_URL, TEST_CHAIN_ID);
-
-      const gasFeeEstimate = await fetchGasPrice(provider, NATIVE_TEST_TOKEN);
-      expectToBeDefined(gasFeeEstimate);
-      expect(gasFeeEstimate.value.toString()).toEqual('3000000000');
-      expect(gasFeeEstimate.token.type).toEqual('native');
+      const lastBaseFeePerGas = BigNumber.from('49'); // 49 wei
+      const maxPriorityFeePerGas = BigNumber.from('500000000'); // 0.5 gwei
+
+      const provider = {
+        getBlock: async () => buildBlock({ baseFeePerGas: lastBaseFeePerGas }),
+        send: jest.fn().mockResolvedValueOnce(maxPriorityFeePerGas),
+      };
+
+      const gasPriceEstimate = await fetchGasPrice(provider, NATIVE_TEST_TOKEN);
+      expectToBeDefined(gasPriceEstimate);
+      expect(gasPriceEstimate.value.toString()).toEqual('500000098'); // maxPriorityFeePerGas + 2 * lastBaseFeePerGas
+      expect(gasPriceEstimate.token.type).toEqual('native');
     });
   });
 });
diff --git a/packages/internal/dex/sdk/src/lib/transactionUtils/gas.ts b/packages/internal/dex/sdk/src/lib/transactionUtils/gas.ts
@@ -1,49 +1,53 @@
-import { BigNumber } from 'ethers';
-import { JsonRpcProvider, FeeData } from '@ethersproject/providers';
+import { BigNumber, providers } from 'ethers';
 import { newAmount } from 'lib';
 import { CoinAmount, Native } from 'types';
 
-type EIP1559FeeData = {
+type FeeData = {
   maxFeePerGas: BigNumber;
   maxPriorityFeePerGas: BigNumber;
   lastBaseFeePerGas: BigNumber;
-  gasPrice: null;
 };
 
-/**
- * Determines whether or not the chain supports EIP-1559 by checking for the existence
- * of {@link FeeData.maxFeePerGas} and {@link FeeData.maxPriorityFeePerGas}
- *
- * @param {FeeData} fee - The fee data for the chain
- */
-export const doesChainSupportEIP1559 = (fee: FeeData): fee is EIP1559FeeData => {
-  const supportsEIP1559 = !!fee.maxFeePerGas && !!fee.maxPriorityFeePerGas;
-  return supportsEIP1559;
+interface Provider {
+  getBlock(blockHashOrBlockTag: string): Promise<providers.Block>
+  send(method: string, params: Array<any>): Promise<any>
+}
+
+const getFeeData = async (provider: Provider): Promise<FeeData> => {
+  const [block, maxPriorityFeePerGas] = await Promise.all([
+    provider.getBlock('latest'),
+    provider.send('eth_maxPriorityFeePerGas', []) as Promise<BigNumber>,
+  ]);
+
+  if (!block.baseFeePerGas) throw new Error('Base fee per gas not found in block');
+
+  return {
+    // https://www.blocknative.com/blog/eip-1559-fees
+    maxFeePerGas: block.baseFeePerGas.mul(2).add(maxPriorityFeePerGas),
+    maxPriorityFeePerGas,
+    lastBaseFeePerGas: block.baseFeePerGas,
+  };
 };
 
 /**
  * Fetch the current gas price estimate. Supports both EIP-1559 and non-EIP1559 chains
- * @param {JsonRpcProvider} provider - The JSON RPC provider used to fetch fee data
+ * @param {Provider} provider - The JSON RPC provider used to fetch fee data
  * @param {Native} nativeToken - The native token of the chain. Gas prices will be denominated in this token
- * @returns {Amount | null} - The gas price in the smallest denomination of the chain's currency,
+ * @returns {CoinAmount<Native> | null} - The gas price in the smallest denomination of the chain's currency,
  *  or null if no gas price is available
  */
-export const fetchGasPrice = async (provider: JsonRpcProvider, nativeToken: Native)
-: Promise<CoinAmount<Native> | null> => {
-  const feeData = await provider.getFeeData().catch(() => null);
+// eslint-disable-next-line max-len
+export const fetchGasPrice = async (provider: Provider, nativeToken: Native): Promise<CoinAmount<Native> | null> => {
+  const feeData = await getFeeData(provider).catch(() => null);
   if (!feeData) return null;
 
-  if (doesChainSupportEIP1559(feeData)) {
-    return newAmount(feeData.maxFeePerGas.add(feeData.maxPriorityFeePerGas), nativeToken);
-  }
-
-  return feeData.gasPrice ? newAmount(feeData.gasPrice, nativeToken) : null;
+  return newAmount(feeData.maxFeePerGas, nativeToken);
 };
 
 /**
  * Calculate the gas fee from the gas price and gas units used for the transaction
  *
- * @param {Amount} gasPrice - The price of gas
+ * @param {CoinAmount<Native>} gasPrice - The price of gas
  * @param {BigNumber} gasEstimate - The total gas units that will be used for the transaction
  * @returns - The cost of the transaction in the gas token's smallest denomination (e.g. WEI)
  */

diff --git a/packages/internal/dex/sdk/src/test/utils.ts b/packages/internal/dex/sdk/src/test/utils.ts
@@ -1,5 +1,5 @@
 import { TradeType } from '@uniswap/sdk-core';
-import { BigNumber, BigNumberish, utils } from 'ethers';
+import { BigNumber, BigNumberish, utils, providers } from 'ethers';
 import { Pool, Route, TickMath } from '@uniswap/v3-sdk';
 import { SwapRouter } from '@uniswap/router-sdk';
 import { Environment, ImmutableConfiguration } from '@imtbl/config';
@@ -11,7 +11,9 @@ import { NativeTokenService } from 'lib/nativeTokenService';
 import { ExchangeModuleConfiguration, SecondaryFee, CoinAmount, Coin, ERC20, Native, Amount } from 'types';
 import { erc20ToUniswapToken, newAmount, Router, RoutingContracts } from '../lib';
 
-export const TEST_GAS_PRICE = BigNumber.from('1500000000'); // 1.5 gwei or 1500000000 wei
+export const TEST_BASE_FEE = BigNumber.from('49'); // 49 wei
+export const TEST_MAX_PRIORITY_FEE_PER_GAS = BigNumber.from('10000000000'); // 10 gwei
+export const TEST_GAS_PRICE = BigNumber.from('10000000098'); // TEST_MAX_PRIORITY_FEE_PER_GAS + 2 * TEST_BASE_FEE
 export const TEST_TRANSACTION_GAS_USAGE = BigNumber.from('200000'); // 200,000 gas units
 
 export const TEST_CHAIN_ID = 999;
@@ -519,3 +521,20 @@ export function newAmountFromString<T extends Coin>(amount: string, token: T): C
   const bn = utils.parseUnits(amount, token.decimals);
   return newAmount(bn, token);
 }
+
+export const buildBlock = ({ baseFeePerGas }: { baseFeePerGas: BigNumber | null }): providers.Block => ({
+  baseFeePerGas,
+  // eslint-disable-next-line @typescript-eslint/naming-convention
+  _difficulty: BigNumber.from('0'),
+  difficulty: 0,
+  extraData: '',
+  gasLimit: BigNumber.from('0'),
+  gasUsed: BigNumber.from('0'),
+  hash: '',
+  miner: '',
+  nonce: '',
+  number: 0,
+  parentHash: '',
+  timestamp: 0,
+  transactions: [],
+});