From 11ab19ad02eeb4667e048579708de351f2fbaae6 Mon Sep 17 00:00:00 2001
From: jrmeurer <jrmeurer@wisc.edu>
Date: Mon, 19 Jun 2023 13:10:51 -0600
Subject: [PATCH] Remove polling rpcs from default fallback config

---
 src/utils/__tests__/available-rpc.test.ts     | 59 +++++++++++++++++++
 src/utils/available-rpc.ts                    |  1 +
 ...der.ts => configured-json-rpc-provider.ts} |  8 +--
 src/utils/fallback-provider.ts                | 13 +++-
 4 files changed, 71 insertions(+), 10 deletions(-)
 create mode 100644 src/utils/__tests__/available-rpc.test.ts
 rename src/utils/{polling-json-rpc-provider.ts => configured-json-rpc-provider.ts} (58%)

diff --git a/src/utils/__tests__/available-rpc.test.ts b/src/utils/__tests__/available-rpc.test.ts
new file mode 100644
index 0000000..ecaa7b5
--- /dev/null
+++ b/src/utils/__tests__/available-rpc.test.ts
@@ -0,0 +1,59 @@
+import chai from 'chai';
+import chaiAsPromised from 'chai-as-promised';
+import {
+  FallbackProviderJsonConfig,
+  createFallbackProviderFromJsonConfig,
+} from '../fallback-provider';
+
+chai.use(chaiAsPromised);
+const { expect } = chai;
+
+describe('available-rpc', () => {
+  it('Should check fallback provider cascade', async () => {
+    const config: FallbackProviderJsonConfig = {
+      chainId: 1,
+      providers: [
+        {
+          provider:
+            'https://eth-mainnet.gateway.pokt.network/v1/lb/627a4b6e18e53a003a6b6c26',
+          priority: 1,
+          weight: 2,
+          stallTimeout: 2500,
+        },
+        {
+          provider: 'https://railwayapi.xyz/rpc/alchemy/eth-mainnet',
+          priority: 2,
+          weight: 1,
+        },
+        { provider: 'https://cloudflare-eth.com/', priority: 3, weight: 1 },
+        { provider: 'https://rpc.ankr.com/eth', priority: 3, weight: 1 },
+      ],
+    };
+
+    const fallbackProvider = createFallbackProviderFromJsonConfig(config);
+
+    await fallbackProvider.getBlockNumber();
+  });
+
+  it('Should sort ascending and descending', () => {
+    const allConfigs = [
+      {
+        priority: 3,
+      },
+      {
+        priority: 1,
+      },
+      {
+        priority: 2,
+      },
+    ];
+
+    // Ascending
+    allConfigs.sort((a, b) => a.priority - b.priority);
+    expect(allConfigs.map(c => c.priority)).to.deep.equal([1, 2, 3]);
+
+    // Descending
+    allConfigs.sort((a, b) => b.priority - a.priority);
+    expect(allConfigs.map(c => c.priority)).to.deep.equal([3, 2, 1]);
+  });
+});
diff --git a/src/utils/available-rpc.ts b/src/utils/available-rpc.ts
index bc84858..9365b31 100644
--- a/src/utils/available-rpc.ts
+++ b/src/utils/available-rpc.ts
@@ -1,3 +1,4 @@
+/// <reference types="../types/global" />
 import { JsonRpcProvider, Network } from 'ethers';
 import { ProviderJson } from './fallback-provider';
 import { getUpperBoundMedian } from './median';
diff --git a/src/utils/polling-json-rpc-provider.ts b/src/utils/configured-json-rpc-provider.ts
similarity index 58%
rename from src/utils/polling-json-rpc-provider.ts
rename to src/utils/configured-json-rpc-provider.ts
index 6ef593f..2791184 100644
--- a/src/utils/polling-json-rpc-provider.ts
+++ b/src/utils/configured-json-rpc-provider.ts
@@ -1,19 +1,13 @@
 import { JsonRpcProvider, JsonRpcApiProviderOptions, Network } from 'ethers';
 
-/**
- * Uses a setting in JsonRpcProvider to poll for events,
- * rather than using sparsely-implemented eth_filter events.
- */
-export class PollingJsonRpcProvider extends JsonRpcProvider {
+export class ConfiguredJsonRpcProvider extends JsonRpcProvider {
   constructor(url: string, network: Network, disableBatching = false) {
     const options: JsonRpcApiProviderOptions = {
-      polling: true,
       staticNetwork: network,
     };
     if (disableBatching) {
       options.batchMaxCount = 1;
     }
     super(url, network, options);
-    this.pollingInterval = 30000;
   }
 }
diff --git a/src/utils/fallback-provider.ts b/src/utils/fallback-provider.ts
index f5e767b..1c725f0 100644
--- a/src/utils/fallback-provider.ts
+++ b/src/utils/fallback-provider.ts
@@ -1,6 +1,9 @@
 import { FallbackProvider, Network, WebSocketProvider } from 'ethers';
-import { PollingJsonRpcProvider } from './polling-json-rpc-provider';
-import { FallbackProviderConfig } from 'ethers/lib.commonjs/providers/provider-fallback';
+import { ConfiguredJsonRpcProvider } from './configured-json-rpc-provider';
+import {
+  FallbackProviderConfig,
+  FallbackProviderOptions,
+} from 'ethers/lib.commonjs/providers/provider-fallback';
 
 export type FallbackProviderJsonConfig = {
   chainId: number;
@@ -42,7 +45,11 @@ export const createFallbackProviderFromJsonConfig = (
         const isWebsocket = providerURL.startsWith('wss');
         const provider = isWebsocket
           ? new WebSocketProvider(providerURL, network)
-          : new PollingJsonRpcProvider(providerURL, network, disableBatching);
+          : new ConfiguredJsonRpcProvider(
+              providerURL,
+              network,
+              disableBatching,
+            );
 
         const fallbackProviderConfig: FallbackProviderConfig = {
           provider,