Add readme with examples

README.md

@@ -0,0 +1,87 @@
+# Tornado oracles
+
+This is a library providing convenient and fast access to oracles for Tornado-specific transactions, for example, withdrawal via relayer or getting rate to ETH for tokens that used in Tornado pools
+
+### Installation
+
+<hr>
+
+* Create `.npmrc` file in project root with content `@tornado:registry=https://git.tornado.ws/api/packages/tornado-packages/npm/`
+* Run `npm i @tornado/tornado-oracles`
+
+
+
+### Import
+
+<hr>
+
+```typescript
+const {TornadoFeeOracleV5, TornadoFeeOracleV5, TokenPriceOracle} = require('@tornado/tornado-oracles')
+or
+import {TornadoFeeOracleV5, TornadoFeeOracleV5, TokenPriceOracle} from '@tornado/tornado-oracles'
+```
+
+
+
+### Usage
+
+<hr>
+
+##### Estimate withdrawal gas costs
+
+```typescript
+import { TornadoFeeOracleV5 } from '@tornado/tornado-oracles'
+
+const tx: TransactionData = {
+    to: tornadoProxyLightAddress,
+    data: poolInstance.methods.withdraw(...params).encodeABI(),
+    value: withdrawalProofArgs[5]
+}
+
+const feeOracle = new TornadoFeeOracleV5(1, "https://eth.llamarpc.com"); // First parameter - chain ID
+const withdrawalGas = await feeOracle.getGas(tx, "relayer_withdrawal");
+```
+
+##### Estimate gas price and gas limit to send transaction
+
+```typescript
+import { TornadoFeeOracleV5 } from '@tornado/tornado-oracles'
+
+const incompleteTx: TransactionData = {
+    to: tornadoProxyLightAddress,
+    data: poolInstance.methods.withdraw(...params).encodeABI(),
+    value: withdrawalProofArgs[5]
+}
+
+const feeOracle = new TornadoFeeOracleV5(1, "https://eth.llamarpc.com");
+const transactionType: TxType = "relayer_withdrawal";
+const gasPrice = await feeOracle.getGasPriceInHex(transactionType);
+const gasLimit = await feeOracle.getGasLimit(incompleteTx, transactionType);
+
+const tx: TransactionData = Object.assign({ gasPrice, gasLimit }, incompleteTx);
+```
+
+##### Get token prices (rate to ETH) for tokens that used in Tornado
+
+```typescript
+import { TokenPriceOracle } from '@tornado/tornado-oracles'
+
+const priceOracle = new TokenPriceOracle("https://eth.llamarpc.com");
+const tokenPrices = await priceOracle.fetchPrices();
+
+console.log(tokenPrices); // All prices in WEI
+/* 
+{
+  torn: '1653773547906175', 
+  dai: '603108348359886',
+  cdai: '13487984643748',
+  usdc: '601311723569085',
+  usdt: '602058974373161',
+  wbtc: '15696224089898846959'
+}
+*/
+```
+
+### License
+
+[MIT](LICENSE)

src/feeOracle.ts

@@ -60,7 +60,7 @@ export abstract class TornadoFeeOracle implements ITornadoFeeOracle {
    * @param {TxType} type Tornado transaction type (to select correct default bump percent)
    * @param {LegacyGasPriceKey} speed Preferred transaction speed, if uses legacy gas (before EIP-1559)
    * @param {number} bumpPercent Gas bump percent to prioritize transaction
-   * @returns {GasPrice} Estimated gas price info in WEI (hexed) - legacy object with gasPrice property or EIP-1559 object with maxFeePerGas
+   * @returns {Promise<GasPrice>} Estimated gas price info in WEI (hexed) - legacy object with gasPrice property or EIP-1559 object with maxFeePerGas
    *  and maxPriorityFeePerGas properties
    */
   async getGasPrice(
@@ -75,6 +75,22 @@ export abstract class TornadoFeeOracle implements ITornadoFeeOracle {
     }
   }
 
+  /**
+   * Estimate next block gas price
+   * @param {TxType} type Tornado transaction type (to select correct default bump percent)
+   * @param {LegacyGasPriceKey} speed Preferred transaction speed, if uses legacy gas (before EIP-1559)
+   * @param {number} bumpPercent Gas bump percent to prioritize transaction
+   * @returns {Promise<string>} Gas price in WEI (hex string)
+   */
+  async getGasPriceInHex(
+    type: TxType = 'other',
+    speed: LegacyGasPriceKey = 'fast',
+    bumpPercent: number = 0,
+  ): Promise<string> {
+    const gasPrice = await this.getGasPrice(type, speed, bumpPercent);
+    return calculateGasPriceInWei(gasPrice).toHexString();
+  }
+
   /**
    * Estimates gas limit for transaction (or basic gas limit, if no tx data provided)
    * @param {TransactionData} tx Transaction data (object in web3 / ethers format)

src/feeOracleV4.ts

@@ -17,12 +17,12 @@ export class TornadoFeeOracleV4 extends TornadoFeeOracle implements ITornadoFeeO
     super(chainId, rpcUrl, gasPriceOracle);
   }
 
-  async getGasLimit(tx?: TransactionData, type: TxType = 'other'): Promise<BigNumber> {
+  async getGasLimit(tx?: TransactionData, type: TxType = 'other', bumpPercent?: number): Promise<BigNumber> {
     if (type === 'user_withdrawal') return BigNumber.from(defaultWithdrawalGasLimit[this.chainId]);
 
     // Need to bump relayer gas limit for transaction, because predefined gas limit to small to be 100% sure that transaction will be sent
     // This leads to fact that relayer often pays extra for gas from his own funds, however, this was designed by previous developers
-    if (type === 'relayer_withdrawal') return bump(defaultWithdrawalGasLimit[this.chainId], 20);
+    if (type === 'relayer_withdrawal') return bump(defaultWithdrawalGasLimit[this.chainId], bumpPercent || 20);
     if (!tx) return BigNumber.from(21_000);
 
     return this.provider.estimateGas(tx);

src/types.ts

@@ -28,6 +28,7 @@ export interface TransactionData {
 export interface ITornadoFeeOracle {
   getGas: (tx?: TransactionData, type?: TxType) => Promise<BigNumber>;
   getGasPrice: (type?: TxType, speed?: LegacyGasPriceKey, bumpPercent?: number) => Promise<GasPrice>;
+  getGasPriceInHex: (type?: TxType, speed?: LegacyGasPriceKey, bumpPercent?: number) => Promise<string>;
   getGasLimit: (tx?: TransactionData, type?: TxType, bumpPercent?: number) => Promise<BigNumber>;
   calculateRefundInETH: () => Promise<BigNumber>;
   calculateWithdrawalFeeViaRelayer: (

src/utils.ts

@@ -15,7 +15,7 @@ export function serializeTx(tx?: TransactionData | string): string {
 
 export function calculateGasPriceInWei(gasPrice: GasPrice): BigNumber {
   // @ts-ignore
-  return gasPrice.gasPrice || gasPrice.maxFeePerGas;
+  return BigNumber.from(gasPrice.gasPrice || gasPrice.maxFeePerGas);
 }
 
 export function bump(value: BigNumberish, percent: number): BigNumber {