add polygon

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 +18,18 @@ Current onchain list:
 
 - [chainlink](https://etherscan.io/address/0x169e633a2d1e6c10dd91238ba11c4a708dfef37c#readContract)
 
+### Binance Smart Chain
+
+Current offchain list:
+
+- https://bscgas.info/
+
+### Polygon (Matic) Network
+
+Current offchain list:
+
+- https://gasstation-mainnet.matic.network/
+
 ## Installation
 
 `npm i gas-price-oracle`
@@ -30,8 +46,15 @@ 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": "0.3.0",
+  "version": "0.3.3",
   "description": "Gas Price Oracle library for Ethereum dApps.",
   "main": "lib/index.js",
   "homepage": "https://github.com/peppersec/gas-price-oracle",

src/config/binance.ts

@@ -3,7 +3,7 @@ import { OffChainOracle, OffChainOracles, OnChainOracles } from '../types';
 const bscgas: OffChainOracle = {
   name: 'bscgas',
   url: 'https://bscgas.info/gas',
-  instantPropertyName: 'imediate',
+  instantPropertyName: 'instant',
   fastPropertyName: 'fast',
   standardPropertyName: 'standard',
   lowPropertyName: 'slow',

src/config/index.ts

@@ -1,25 +1,16 @@
 import { NetworkConfig } from '../types';
-import {
-  onChainOracles as mainnetOnchainOracles,
-  offChainOracles as mainnetOffChainOracles,
-} from './mainnet';
-import {
-  onChainOracles as binanceOnchainOracles,
-  offChainOracles as binanceOffchainOracles,
-} from './binance';
+import mainnetOracles from './mainnet';
+import binanceOracles from './binance';
+import polygonOracles from './polygon';
 
 export enum ChainId {
   MAINNET = 1,
   BINANCE = 56,
+  POLYGON = 137,
 }
 
 export const networks: NetworkConfig = {
-  [ChainId.MAINNET]: {
-    onChainOracles: mainnetOnchainOracles,
-    offChainOracles: mainnetOffChainOracles,
-  },
-  [ChainId.BINANCE]: {
-    onChainOracles: binanceOnchainOracles,
-    offChainOracles: binanceOffchainOracles,
-  },
+  [ChainId.MAINNET]: mainnetOracles,
+  [ChainId.BINANCE]: binanceOracles,
+  [ChainId.POLYGON]: polygonOracles,
 };

src/config/polygon.ts

@@ -0,0 +1,23 @@
+import { OffChainOracle, OffChainOracles, OnChainOracles } from '../types';
+
+const maticGasStation: OffChainOracle = {
+  name: 'maticGasStation',
+  url: 'https://gasstation-mainnet.matic.network',
+  instantPropertyName: 'fastest',
+  fastPropertyName: 'fast',
+  standardPropertyName: 'standard',
+  lowPropertyName: 'safeLow',
+  denominator: 1,
+  additionalDataProperty: null,
+};
+
+export const offChainOracles: OffChainOracles = {
+  maticGasStation,
+};
+
+export const onChainOracles: OnChainOracles = {};
+
+export default {
+  offChainOracles,
+  onChainOracles,
+};

src/index.ts

@@ -12,6 +12,7 @@ import {
 } from './types';
 import BigNumber from 'bignumber.js';
 
+const defaultFastGas = 22;
 export class GasPriceOracle {
   lastGasPrice: GasPrice;
   offChainOracles: OffChainOracles;
@@ -20,6 +21,12 @@ export class GasPriceOracle {
     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) {
@@ -175,14 +182,7 @@ export class GasPriceOracle {
   }
 
   async gasPrices(fallbackGasPrices?: GasPrice, median = true): Promise<GasPrice> {
-    const defaultFastGas = 22;
-    const defaultFallbackGasPrices = {
-      instant: defaultFastGas * 1.3,
-      fast: defaultFastGas,
-      standard: defaultFastGas * 0.85,
-      low: defaultFastGas * 0.5,
-    };
-    this.lastGasPrice = this.lastGasPrice || fallbackGasPrices || defaultFallbackGasPrices;
+    this.lastGasPrice = this.lastGasPrice || fallbackGasPrices || this.configuration.defaultFallbackGasPrices;
     try {
       this.lastGasPrice = median
         ? await this.fetchMedianGasPriceOffChain()

src/types.ts

@@ -21,6 +21,11 @@ export type OnChainOracle = {
 
 export type OnChainOracles = { [key: string]: OnChainOracle };
 
+export type AllOracles = {
+  offChainOracles: OffChainOracles;
+  onChainOracles: OnChainOracles;
+};
+
 export type GasPrice = {
   [key in GasPriceKey]: number;
 };
@@ -31,13 +36,11 @@ export type Options = {
   chainId?: number;
   defaultRpc?: string;
   timeout?: number;
+  defaultFallbackGasPrices?: GasPrice;
 };
 
 export type Config = Required<Options>;
 
 export type NetworkConfig = {
-  [key in number]: {
-    offChainOracles: OffChainOracles;
-    onChainOracles: OnChainOracles;
-  };
+  [key in number]: AllOracles;
 };

tests/index.test.ts

@@ -207,9 +207,6 @@ describe('fetchMedianGasPriceOffChain', function () {
 
 describe('askOracle', function () {
   it('all oracles should answer', async function () {
-    // TODO: remove after fix POA
-    delete offChainOracles['poa'];
-
     for (const o of Object.values(offChainOracles) as Array<OffChainOracle>) {
       try {
         const gas: GasPrice = await oracle.askOracle(o);