feat: QoL improvements to write alerts script (hyperlane-xyz#5998)

### Description

- properly handle port forward process on exit
- prompt user to confirm threshold changes have been reviewed

### Testing

Manual

Author: Mo-Hussain

typescript/infra/scripts/funding/write-alert.ts

@@ -48,6 +48,16 @@ interface RegressionError {
 async function main() {
   const { dryRun } = await withDryRun(yargs(process.argv.slice(2))).argv;
 
+  const confirmed = await confirm({
+    message:
+      'Before proceeding, please ensure that any threshold changes have been committed and reviewed in a PR, have all changes been reviewed?',
+  });
+
+  if (!confirmed) {
+    rootLogger.info('Exiting without updating any alerts');
+    process.exit(0);
+  }
+
   // runs a validation check to ensure the threshold configs are valid relative to each other
   await validateBalanceThresholdConfigs();
 
@@ -56,25 +66,29 @@ async function main() {
     PROMETHEUS_LOCAL_PORT,
   );
 
-  const alertsToUpdate = Object.values(AlertType);
-  const alertUpdateInfo: AlertUpdateInfo[] = [];
-  const missingChainErrors: RegressionError[] = [];
+  process.on('SIGINT', () => {
+    cleanUp(portForwardProcess);
+    process.exit(1);
+  });
+
+  process.on('beforeExit', () => {
+    cleanUp(portForwardProcess);
+  });
 
   try {
+    const alertsToUpdate = Object.values(AlertType);
+    const alertUpdateInfo: AlertUpdateInfo[] = [];
+    const missingChainErrors: RegressionError[] = [];
+
     for (const alert of alertsToUpdate) {
       // fetch alertRule config from Grafana via the Grafana API
       const alertRule = await fetchGrafanaAlert(alert, saToken);
 
       // read the proposed thresholds from the config file
       let proposedThresholds: ChainMap<number> = {};
-      try {
-        proposedThresholds = readJSONAtPath(
-          `${THRESHOLD_CONFIG_PATH}/${alertConfigMapping[alert].configFileName}`,
-        );
-      } catch (e) {
-        rootLogger.error(`Error reading ${alert} config: ${e}`);
-        process.exit(1);
-      }
+      proposedThresholds = readJSONAtPath(
+        `${THRESHOLD_CONFIG_PATH}/${alertConfigMapping[alert].configFileName}`,
+      );
 
       // parse the current thresholds from the existing query
       const existingQuery = alertRule.queries[0];
@@ -112,6 +126,7 @@ async function main() {
           rootLogger.info(
             `Exiting without updating any alerts, this is to avoid thresholds from being out of sync`,
           );
+          cleanUp(portForwardProcess);
           process.exit(0);
         }
       } else {
@@ -128,6 +143,7 @@ async function main() {
         query,
         currentThresholds,
         proposedThresholds,
+        portForwardProcess,
       );
 
       alertUpdateInfo.push({
@@ -148,7 +164,7 @@ async function main() {
       rootLogger.info('Dry run, not updating alerts');
     }
   } finally {
-    portForwardProcess.kill();
+    cleanUp(portForwardProcess);
   }
 }
 
@@ -220,7 +236,7 @@ async function updateAlerts(
         `Error updating ${alertInfo.alertType} alert, aborting updating the rest of the alerts: ${e}`,
       );
       // exiting here so we don't continue updating alerts with lower writePriority
-      portForwardProcess.kill();
+      cleanUp(portForwardProcess);
       process.exit(1);
     }
   }
@@ -294,6 +310,7 @@ async function confirmFiringAlerts(
   query: string,
   currentThresholds: ChainMap<number>,
   proposedThresholds: ChainMap<number>,
+  portForwardProcess: ChildProcess,
 ) {
   const alertingChains = await fetchFiringThresholdAlert(query);
   if (alertingChains.length === 0) return;
@@ -316,10 +333,18 @@ async function confirmFiringAlerts(
     rootLogger.info(
       `Exiting without updating any alerts, this is to avoid thresholds from being out of sync as we do not want to update the ${alert} alert`,
     );
+    cleanUp(portForwardProcess);
     process.exit(0);
   }
 }
 
+function cleanUp(portForwardProcess: ChildProcess) {
+  if (!portForwardProcess.killed) {
+    rootLogger.info('Cleaning up port forward process');
+    portForwardProcess.kill();
+  }
+}
+
 main().catch((err) => {
   console.error(err);
   process.exit(1);