Only save successful assets to the asset caches

Assets that cannot have not found a rate, like obscure or invalid tokens, shouldn't slow down the initial lookup on login

Fix eslint error in exchangeRates.ts

Author: peachbits

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased (develop)
 
+- changed: Optimize exchange rate fetching and asset pair cache handling
 - fixed: Fixed broken `logEvent` tracking calls by adding the needed `dispatch`.
 - removed: Remove change quote tracking.
 

eslint.config.mjs

@@ -496,7 +496,6 @@ export default [
       'src/util/CurrencyInfoHelpers.ts',
       'src/util/CurrencyWalletHelpers.ts',
 
-      'src/util/exchangeRates.ts',
       'src/util/fake/FakeProviders.tsx',
       'src/util/FioAddressUtils.ts',
       'src/util/getAccountUsername.ts',

src/actions/ExchangeRateActions.ts

@@ -6,6 +6,7 @@ import type { ThunkAction } from '../types/reduxTypes'
 import {
   asCryptoAsset,
   asRatesParams,
+  createRateKey,
   type RatesParams
 } from '../util/exchangeRates'
 import { fetchRates } from '../util/network'
@@ -308,6 +309,8 @@ async function fetchExchangeRates(
     }
   }
 
+  const cryptoPairCache = new Map<string, CryptoFiatPair>()
+  const fiatPairCache = new Map<string, FiatFiatPair>()
   const requests = convertToRatesParams(cryptoPairMap, fiatPairMap)
   const promises = requests.map(async query => {
     const options = {
@@ -362,6 +365,14 @@ async function fetchExchangeRates(
           }
 
           rateObj.expiration = rateExpiration
+
+          // Save crypto assets with rates to asset cache
+          cryptoPairCache.set(createRateKey(cryptoRate.asset, targetFiat), {
+            asset: cryptoRate.asset,
+            targetFiat,
+            isoDate: undefined,
+            expiration: pairExpiration
+          })
         }
         for (const fiatRate of cleanedRates.fiat) {
           const { isoDate, rate } = fiatRate
@@ -398,6 +409,14 @@ async function fetchExchangeRates(
           }
 
           rateObj.expiration = rateExpiration
+
+          // Save fiat assets with rates to asset cache
+          fiatPairCache.set(createRateKey(fiatCode, targetFiat), {
+            fiatCode,
+            targetFiat,
+            isoDate: undefined,
+            expiration: pairExpiration
+          })
         }
       }
     } catch (error: unknown) {
@@ -411,8 +430,8 @@ async function fetchExchangeRates(
   // Update the in-memory cache:
   exchangeRateCache = {
     rates,
-    cryptoPairs: Array.from(cryptoPairMap.values()),
-    fiatPairs: Array.from(fiatPairMap.values())
+    cryptoPairs: Array.from(cryptoPairCache.values()),
+    fiatPairs: Array.from(fiatPairCache.values())
   }
 
   // Write the cache to disk:

src/util/exchangeRates.ts

@@ -127,7 +127,7 @@ const doQuery = async (doFetch?: EdgeFetchFunction): Promise<void> => {
 
               clog(`${n} deleting ${key}`)
               resolverMap.delete(key)
-              if (resolvers.length) {
+              if (resolvers.length > 0) {
                 resolvers.forEach((r, i) => {
                   r(rate)
                 })
@@ -163,7 +163,7 @@ const doQuery = async (doFetch?: EdgeFetchFunction): Promise<void> => {
 
               clog(`${n} deleting ${key}`)
               resolverMap.delete(key)
-              if (resolvers.length) {
+              if (resolvers.length > 0) {
                 resolvers.forEach((r, i) => {
                   r(rate)
                 })
@@ -205,7 +205,7 @@ const addToQueue = (
   resolve: Function,
   maxQuerySize: number,
   doFetch?: EdgeFetchFunction
-) => {
+): void => {
   const rateKeyResolver = resolverMap.get(rateKey)
   if (rateKeyResolver == null) {
     // Create a new entry in the map for this pair/date
@@ -229,7 +229,7 @@ const addToQueue = (
   }
 }
 
-const createRateKey = (
+export const createRateKey = (
   asset: { pluginId: string; tokenId?: EdgeTokenId } | string,
   targetFiat: string,
   date?: string