feat: store withdrawals executed status in cache

packages/arb-token-bridge-ui/src/util/withdrawals/helpers.ts

@@ -101,19 +101,23 @@ export async function mapETHWithdrawalToL2ToL1EventResult({
   }
 }
 
+let localStoragePromise = Promise.resolve()
+
 export async function getOutgoingMessageState(
   event: L2ToL1EventResult,
   l1Provider: Provider,
   l2Provider: Provider,
   l2ChainID: number
 ) {
+  const localStorageKey = 'arbitrum:bridge:executed-messages'
+
   const cacheKey = getExecutedMessagesCacheKey({
     event,
     l2ChainId: l2ChainID
   })
 
   const executedMessagesCache = JSON.parse(
-    localStorage.getItem('arbitrum:bridge:executed-messages') || '{}'
+    localStorage.getItem(localStorageKey) || '{}'
   )
   if (executedMessagesCache[cacheKey]) {
     return OutgoingMessageState.EXECUTED
@@ -122,7 +126,26 @@ export async function getOutgoingMessageState(
   const messageReader = new ChildToParentMessageReader(l1Provider, event)
 
   try {
-    return await messageReader.status(l2Provider)
+    const status = await messageReader.status(l2Provider)
+
+    if (status === OutgoingMessageState.EXECUTED) {
+      // Ensures all parallel methods save to local storage sequentially
+      localStoragePromise = localStoragePromise.then(() => {
+        const latestExecutedMessagesCache = JSON.parse(
+          localStorage.getItem(localStorageKey) || '{}'
+        )
+
+        localStorage.setItem(
+          localStorageKey,
+          JSON.stringify({
+            ...latestExecutedMessagesCache,
+            [cacheKey]: true
+          })
+        )
+      })
+    }
+
+    return status
   } catch (error) {
     return OutgoingMessageState.UNCONFIRMED
   }