Fix spread syntax runtime error on non-iterable values

Replace unsafe non-null assertions and truthy guards with Array.isArray
checks before spreading webhook subscription properties in
reduceWebhooks. Use flatMap with nullish coalescing in esbuild watcher
deleteContexts. Remove fragile Map.get()! in app-logs sources.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: durga256

packages/app/src/cli/models/extensions/specifications/transform/app_config_webhook.ts

@@ -80,15 +80,15 @@ export function reduceWebhooks(
   return subscriptions.reduce<WebhookSubscription[]>((accumulator, subscription) => {
     const existingSubscription = findSubscription(accumulator, subscription)
     if (existingSubscription) {
-      if (property && subscription?.[property]?.length) {
-        // eslint-disable-next-line @typescript-eslint/no-unnecessary-type-assertion
-        existingSubscription[property]?.push(...subscription[property]!)
+      if (property && Array.isArray(subscription?.[property]) && subscription[property].length) {
+        existingSubscription[property] ??= []
+        existingSubscription[property].push(...subscription[property])
       } else {
-        if (subscription.topics) {
+        if (Array.isArray(subscription.topics)) {
           existingSubscription.topics ??= []
           existingSubscription.topics.push(...subscription.topics)
         }
-        if (subscription.compliance_topics) {
+        if (Array.isArray(subscription.compliance_topics)) {
           existingSubscription.compliance_topics ??= []
           existingSubscription.compliance_topics.push(...subscription.compliance_topics)
         }

packages/app/src/cli/services/app-logs/sources.ts

@@ -15,7 +15,8 @@ export function sources(app: AppInterface) {
         sourcesByNamespace.set(sourceNamespace, [])
       }
 
-      sourcesByNamespace.set(sourceNamespace, [...sourcesByNamespace.get(sourceNamespace)!, source])
+      const existing = sourcesByNamespace.get(sourceNamespace) ?? []
+      sourcesByNamespace.set(sourceNamespace, [...existing, source])
     }
   })
 

packages/app/src/cli/services/dev/app-events/app-watcher-esbuild.ts

@@ -116,7 +116,7 @@ export class ESBuildContextManager {
   }
 
   async deleteContexts(extensions: ExtensionInstance[]) {
-    const promises = extensions.map((ext) => this.contexts[ext.uid]?.map((context) => context.dispose())).flat()
+    const promises = extensions.flatMap((ext) => this.contexts[ext.uid]?.map((context) => context.dispose()) ?? [])
     await Promise.all(promises)
     extensions.forEach((ext) => {
       const {[ext.uid]: _, ...rest} = this.contexts