Only add or update cached pairs if they successfully return a rate

Author: peachbits

src/actions/ExchangeRateActions.ts

@@ -408,11 +408,64 @@ async function fetchExchangeRates(
   })
   await Promise.allSettled(promises)
 
+  // Merge successful rate responses into the pair cache
+  const cryptoPairCache = [...(exchangeRateCache?.cryptoPairs ?? [])]
+  const fiatPairCache = [...(exchangeRateCache?.fiatPairs ?? [])]
+  const pairCacheExpiration = Date.now() + ONE_MONTH
+  for (const [pluginId, tokenObj] of Object.entries(rates.crypto)) {
+    for (const [tokenId, rateObj] of Object.entries(tokenObj)) {
+      for (const targetFiat of Object.keys(rateObj)) {
+        const cryptoPairIndex = cryptoPairCache.findIndex(
+          pair =>
+            pair.asset.pluginId === pluginId &&
+            pair.asset.tokenId === tokenId &&
+            pair.targetFiat === targetFiat
+        )
+        if (cryptoPairIndex === -1) {
+          cryptoPairCache.push({
+            asset: { pluginId, tokenId },
+            targetFiat,
+            isoDate: undefined,
+            expiration: pairCacheExpiration
+          })
+        } else {
+          cryptoPairCache[cryptoPairIndex] = {
+            asset: { pluginId, tokenId },
+            targetFiat,
+            isoDate: undefined,
+            expiration: pairCacheExpiration
+          }
+        }
+      }
+    }
+  }
+  for (const [fiatCode, fiatObj] of Object.entries(rates.fiat)) {
+    for (const targetFiat of Object.keys(fiatObj)) {
+      const fiatPairIndex = fiatPairCache.findIndex(
+        pair => pair.fiatCode === fiatCode && pair.targetFiat === targetFiat
+      )
+      if (fiatPairIndex === -1) {
+        fiatPairCache.push({
+          fiatCode,
+          targetFiat,
+          isoDate: undefined,
+          expiration: pairCacheExpiration
+        })
+      } else {
+        fiatPairCache[fiatPairIndex] = {
+          fiatCode,
+          targetFiat,
+          isoDate: undefined,
+          expiration: pairCacheExpiration
+        }
+      }
+    }
+  }
   // Update the in-memory cache:
   exchangeRateCache = {
     rates,
-    cryptoPairs: Array.from(cryptoPairMap.values()),
-    fiatPairs: Array.from(fiatPairMap.values())
+    cryptoPairs: cryptoPairCache,
+    fiatPairs: fiatPairCache
   }
 
   // Write the cache to disk: