fix: bscgas property

README.md

@@ -2,6 +2,10 @@
 
 A library that has a collection of onchain and offchain gas price oracle URLs
 
+## Supported networks
+
+### Ethereum Mainnet
+
 Current offchain list:
 
 - https://ethgasstation.info/json/ethgasAPI.json
@@ -14,6 +18,12 @@ Current onchain list:
 
 - [chainlink](https://etherscan.io/address/0x169e633a2d1e6c10dd91238ba11c4a708dfef37c#readContract)
 
+### Binance Smart Chain
+
+Current offchain list:
+
+- https://bscgas.info/
+
 ## Installation
 
 `npm i gas-price-oracle`
@@ -30,8 +40,15 @@ const { GasPriceOracle } = require('gas-price-oracle');
 
 ```js
 const options = {
+  chainId: 1,
   defaultRpc: 'https://api.mycryptoapi.com/eth',
   timeout: 10000,
+  defaultFallbackGasPrices: {
+    instant: 28,
+    fast: 22,
+    standard: 17,
+    low: 11,
+  },
 };
 const oracle = new GasPriceOracle(options);
 // optional fallbackGasPrices

package.json

@@ -1,6 +1,6 @@
 {
   "name": "gas-price-oracle",
-  "version": "0.2.1",
+  "version": "0.3.2",
   "description": "Gas Price Oracle library for Ethereum dApps.",
   "main": "lib/index.js",
   "homepage": "https://github.com/peppersec/gas-price-oracle",

src/config/binance.ts

@@ -0,0 +1,23 @@
+import { OffChainOracle, OffChainOracles, OnChainOracles } from '../types';
+
+const bscgas: OffChainOracle = {
+  name: 'bscgas',
+  url: 'https://bscgas.info/gas',
+  instantPropertyName: 'instant',
+  fastPropertyName: 'fast',
+  standardPropertyName: 'standard',
+  lowPropertyName: 'slow',
+  denominator: 1,
+  additionalDataProperty: null,
+};
+
+export const offChainOracles: OffChainOracles = {
+  bscgas,
+};
+
+export const onChainOracles: OnChainOracles = {};
+
+export default {
+  offChainOracles,
+  onChainOracles,
+};

src/config/index.ts

@@ -0,0 +1,13 @@
+import { NetworkConfig } from '../types';
+import mainnetOracles from './mainnet';
+import binanceOracles from './binance';
+
+export enum ChainId {
+  MAINNET = 1,
+  BINANCE = 56,
+}
+
+export const networks: NetworkConfig = {
+  [ChainId.MAINNET]: mainnetOracles,
+  [ChainId.BINANCE]: binanceOracles,
+};

src/config/mainnet.ts

@@ -1,4 +1,4 @@
-import { OffChainOracle, OnChainOracle } from './types';
+import { OffChainOracle, OnChainOracle, OffChainOracles, OnChainOracles } from '../types';
 
 const ethgasstation: OffChainOracle = {
   name: 'ethgasstation',
@@ -73,7 +73,7 @@ const chainlink: OnChainOracle = {
   denominator: '1000000000',
 };
 
-export const offChainOracles: { [key: string]: OffChainOracle } = {
+export const offChainOracles: OffChainOracles = {
   ethgasstation,
   anyblock,
   gasNow,
@@ -82,7 +82,7 @@ export const offChainOracles: { [key: string]: OffChainOracle } = {
   zoltu,
 };
 
-export const onChainOracles: { [key: string]: OnChainOracle } = {
+export const onChainOracles: OnChainOracles = {
   chainlink,
 };
 

src/index.ts

@@ -1,21 +1,42 @@
 import axios from 'axios';
-import config from './config';
+import { ChainId, networks } from './config';
-import { GasPrice, OffChainOracle, OnChainOracle, Config, GasPriceKey, Options } from './types';
+import {
+  Config,
+  Options,
+  GasPrice,
+  GasPriceKey,
+  OffChainOracle,
+  OnChainOracle,
+  OnChainOracles,
+  OffChainOracles,
+} from './types';
 import BigNumber from 'bignumber.js';
 
+const defaultFastGas = 22;
 export class GasPriceOracle {
   lastGasPrice: GasPrice;
-  offChainOracles = { ...config.offChainOracles };
+  offChainOracles: OffChainOracles;
-  onChainOracles = { ...config.onChainOracles };
+  onChainOracles: OnChainOracles;
   configuration: Config = {
+    chainId: ChainId.MAINNET,
     defaultRpc: 'https://api.mycryptoapi.com/eth',
     timeout: 10000,
+    defaultFallbackGasPrices: {
+      instant: defaultFastGas * 1.3,
+      fast: defaultFastGas,
+      standard: defaultFastGas * 0.85,
+      low: defaultFastGas * 0.5,
+    },
   };
 
   constructor(options?: Options) {
     if (options) {
       Object.assign(this.configuration, options);
     }
+
+    const { offChainOracles, onChainOracles } = networks[this.configuration.chainId];
+    this.offChainOracles = { ...offChainOracles };
+    this.onChainOracles = { ...onChainOracles };
   }
 
   async askOracle(oracle: OffChainOracle): Promise<GasPrice> {
@@ -41,7 +62,7 @@ export class GasPriceOracle {
         standard: parseFloat(gas[standardPropertyName]) / denominator,
         low: parseFloat(gas[lowPropertyName]) / denominator,
       };
-      return gasPrices;
+      return this.normalize(gasPrices);
     } else {
       throw new Error(`Fetch gasPrice from ${name} oracle failed. Trying another one...`);
     }
@@ -108,7 +129,25 @@ export class GasPriceOracle {
       const middle = Math.floor(allPrices.length / 2);
       medianGasPrice[type] = isEven ? (allPrices[middle - 1] + allPrices[middle]) / 2.0 : allPrices[middle];
     }
-    return medianGasPrice;
+    return this.normalize(medianGasPrice);
+  }
+  /**
+   * Normalizes GasPrice values to Gwei. No more than 9 decimals basically
+   * @param GasPrice _gas
+   */
+  normalize(_gas: GasPrice): GasPrice {
+    const format = {
+      decimalSeparator: '.',
+      groupSeparator: '',
+    };
+    const decimals = 9;
+
+    const gas: GasPrice = { ..._gas };
+    for (const type of Object.keys(gas) as Array<keyof GasPrice>) {
+      gas[type] = Number(new BigNumber(gas[type]).toFormat(decimals, format));
+    }
+
+    return gas;
   }
 
   async fetchGasPricesOnChain(): Promise<number> {
@@ -143,14 +182,7 @@ export class GasPriceOracle {
   }
 
   async gasPrices(fallbackGasPrices?: GasPrice, median = true): Promise<GasPrice> {
-    const defaultFastGas = 22;
+    this.lastGasPrice = this.lastGasPrice || fallbackGasPrices || this.configuration.defaultFallbackGasPrices;
-    const defaultFallbackGasPrices = {
-      instant: defaultFastGas * 1.3,
-      fast: defaultFastGas,
-      standard: defaultFastGas * 0.85,
-      low: defaultFastGas * 0.5,
-    };
-    this.lastGasPrice = this.lastGasPrice || fallbackGasPrices || defaultFallbackGasPrices;
     try {
       this.lastGasPrice = median
         ? await this.fetchMedianGasPriceOffChain()

src/types.ts

@@ -9,6 +9,8 @@ export type OffChainOracle = {
   additionalDataProperty: string | null;
 };
 
+export type OffChainOracles = { [key: string]: OffChainOracle };
+
 export type OnChainOracle = {
   name: string;
   rpc?: string;
@@ -17,6 +19,13 @@ export type OnChainOracle = {
   denominator: string;
 };
 
+export type OnChainOracles = { [key: string]: OnChainOracle };
+
+export type AllOracles = {
+  offChainOracles: OffChainOracles;
+  onChainOracles: OnChainOracles;
+};
+
 export type GasPrice = {
   [key in GasPriceKey]: number;
 };
@@ -24,8 +33,14 @@ export type GasPrice = {
 export type GasPriceKey = 'instant' | 'fast' | 'standard' | 'low';
 
 export type Options = {
+  chainId?: number;
   defaultRpc?: string;
   timeout?: number;
+  defaultFallbackGasPrices?: GasPrice;
 };
 
 export type Config = Required<Options>;
+
+export type NetworkConfig = {
+  [key in number]: AllOracles;
+};

tests/index.test.ts

@@ -3,12 +3,12 @@
 import { GasPrice, OffChainOracle } from '../src/types';
 import mockery from 'mockery';
 import chai from 'chai';
-import { onChainOracles, offChainOracles } from '../src/config';
 
 import { GasPriceOracle } from '../src/index';
 chai.use(require('chai-as-promised'));
 chai.should();
 let oracle = new GasPriceOracle();
+let { onChainOracles, offChainOracles } = oracle;
 
 before('before', function () {
   const axiosMock = {
@@ -24,6 +24,7 @@ before('before', function () {
 
 beforeEach('beforeEach', function () {
   oracle = new GasPriceOracle();
+  ({ onChainOracles, offChainOracles } = oracle);
 });
 
 describe('constructor', function () {