retry failed requests up to 3 times

src/state/multicall/updater.tsx

@@ -5,6 +5,7 @@ import { useActiveWeb3React } from '../../hooks'
 import { useMulticallContract } from '../../hooks/useContract'
 import useDebounce from '../../hooks/useDebounce'
 import chunkArray from '../../utils/chunkArray'
+import { retry } from '../../utils/retry'
 import { useBlockNumber } from '../application/hooks'
 import { AppDispatch, AppState } from '../index'
 import {
@@ -142,7 +143,7 @@ export default function Updater() {
     )
 
     chunkedCalls.forEach((chunk, index) =>
-      fetchChunk(multicallContract, chunk, latestBlockNumber)
+      retry(() => fetchChunk(multicallContract, chunk, latestBlockNumber))
         .then(({ results: returnData, blockNumber: fetchBlockNumber }) => {
           // accumulates the length of all previous indices
           const firstCallKeyIndex = chunkedCalls.slice(0, index).reduce<number>((memo, curr) => memo + curr.length, 0)

src/utils/retry.ts

+function wait(ms: number): Promise<void> {
+  return new Promise(resolve => setTimeout(resolve, ms))
+}
+
+function waitRandom(min: number, max: number): Promise<void> {
+  return wait(min + Math.round(Math.random() * (max - min)))
+}
+
+/**
+ * Retries the function that returns the promise until the promise successfully resolves up to n retries
+ * @param fn function to retry
+ * @param n how many times to retry
+ * @param minWait min wait between retries in ms
+ * @param maxWait max wait between retries in ms
+ */
+export function retry<T>(
+  fn: () => Promise<T>,
+  { n = 3, minWait = 500, maxWait = 1000 }: { n?: number; minWait?: number; maxWait?: number } = {}
+): Promise<T> {
+  return fn().catch(error => {
+    if (n === 0) throw error
+    return waitRandom(minWait, maxWait).then(() => retry(fn, { n: n - 1, minWait, maxWait }))
+  })
+}