Merge pull request #380 from 0xProject/feat/update-gas-source

Updating to use 0x Gas API

Author: lyaunzbe

ts/types.ts

@@ -821,17 +821,19 @@ export interface GasInfo {
     estimatedTimeMs: number;
 }
 
-export interface WebsiteBackendGasInfo {
-    average: number;
+export interface WebsiteBackendGasWaitTimeInfo {
     fastestWait: number;
     fastWait: number;
-    fast: number;
     safeLowWait: number;
     blockNum: number;
     avgWait: number;
     block_time: number;
-    speed: number;
+}
+
+export interface WebsiteBackendGasInfo {
     fastest: number;
+    fast: number;
+    average: number;
     safeLow: number;
 }
 

ts/utils/backend_client.ts

@@ -6,6 +6,7 @@ import {
     MailchimpSubscriberInfo,
     WebsiteBackendCFLMetricsData,
     WebsiteBackendGasInfo,
+    WebsiteBackendGasWaitTimeInfo,
     WebsiteBackendJobInfo,
     WebsiteBackendPriceInfo,
     WebsiteBackendRelayerInfo,
@@ -17,6 +18,8 @@ import { constants } from 'ts/utils/constants';
 import { fetchUtils } from 'ts/utils/fetch_utils';
 import { utils } from 'ts/utils/utils';
 
+const ZEROEX_GAS_API = 'https://gas.api.0x.org/';
+
 const ETH_GAS_STATION_ENDPOINT = '/eth_gas_station';
 const JOBS_ENDPOINT = '/jobs';
 const PRICES_ENDPOINT = '/prices';
@@ -29,17 +32,26 @@ const STAKING_POOLS_ENDPOINT = '/staking-pools';
 
 export const backendClient = {
     async getGasInfoAsync(): Promise<GasInfo> {
-        const gasInfo: WebsiteBackendGasInfo = await fetchUtils.requestAsync(
-            utils.getBackendBaseUrl(),
-            ETH_GAS_STATION_ENDPOINT,
-        );
+        // Median gas prices across 0x api gas oracles
+        // Defaulting to average/standard gas. Using eth gas station for time estimates
+        const gasApiPath = 'source/median?output=eth_gas_station';
+        const gasInfoReq = fetchUtils.requestAsync(ZEROEX_GAS_API, gasApiPath);
+        const gasWaitTimesReq = fetchUtils.requestAsync(utils.getBackendBaseUrl(), ETH_GAS_STATION_ENDPOINT);
+
+        const res: [WebsiteBackendGasInfo, WebsiteBackendGasWaitTimeInfo] = await Promise.all([
+            gasInfoReq,
+            gasWaitTimesReq,
+        ]);
+        const gasInfo = res[0];
+        const gasWaitTimes = res[1];
 
         // Eth Gas Station result is gwei * 10
-        const gasPriceInGwei = new BigNumber(gasInfo.fast / 10);
+        const gasPriceInGwei = new BigNumber(gasInfo.average / 10);
         // Time is in minutes
-        const estimatedTimeMs = gasInfo.fastWait * 60 * 1000; // Minutes to MS
+        const estimatedTimeMs = gasWaitTimes.avgWait * 60 * 1000; // Minutes to MS
         return { gasPriceInWei: gasPriceInGwei.multipliedBy(constants.GWEI_IN_WEI), estimatedTimeMs };
     },
+
     async getJobInfosAsync(): Promise<WebsiteBackendJobInfo[]> {
         const result = await fetchUtils.requestAsync(utils.getBackendBaseUrl(), JOBS_ENDPOINT);
         return result;