Add error mapping for Amplify app not found in specified region

.changeset/ninety-coins-jog.md

@@ -0,0 +1,5 @@
+---
+'@aws-amplify/backend-cli': patch
+---
+
+Added error mapping for app name not available in the region

packages/cli/src/backend-identifier/backend_identifier_resolver.ts

@@ -1,7 +1,10 @@
 import { DeployedBackendIdentifier } from '@aws-amplify/deployed-backend-client';
 import { NamespaceResolver } from './local_namespace_resolver.js';
 import { BackendIdentifier } from '@aws-amplify/plugin-types';
-import { BackendIdentifierConversions } from '@aws-amplify/platform-core';
+import {
+  AmplifyUserError,
+  BackendIdentifierConversions,
+} from '@aws-amplify/platform-core';
 
 export type BackendIdentifierParameters = {
   stack?: string;
@@ -30,21 +33,39 @@ export class AppBackendIdentifierResolver implements BackendIdentifierResolver {
   resolveDeployedBackendIdentifier = async (
     args: BackendIdentifierParameters
   ): Promise<DeployedBackendIdentifier | undefined> => {
-    if (args.stack) {
-      return { stackName: args.stack };
-    } else if (args.appId && args.branch) {
-      return {
-        namespace: args.appId,
-        name: args.branch,
-        type: 'branch',
-      };
-    } else if (args.branch) {
-      return {
-        appName: await this.namespaceResolver.resolve(),
-        branchName: args.branch,
-      };
+    try {
+      if (args.stack) {
+        return { stackName: args.stack };
+      } else if (args.appId && args.branch) {
+        return {
+          namespace: args.appId,
+          name: args.branch,
+          type: 'branch',
+        };
+      } else if (args.branch) {
+        const resolvedNamespace = await this.namespaceResolver.resolve();
+        return {
+          appName: resolvedNamespace,
+          branchName: args.branch,
+        };
+      }
+      return undefined;
+    } catch (error) {
+      const appNotFoundMatch = (error as Error).message.match(
+        /No apps found with name (?<appName>.*) in region (?<region>.*)/
+      );
+
+      if (appNotFoundMatch?.groups) {
+        const { appName, region } = appNotFoundMatch.groups;
+        throw new AmplifyUserError('AmplifyAppNotFoundError', {
+          message: `No Amplify app found with name "${appName}" in region "${region}".`,
+          resolution: `Ensure that an Amplify app named "${appName}" exists in the "${region}" region.`,
+        });
+      }
+
+      // Re-throw any other errors
+      throw error;
     }
-    return undefined;
   };
   resolveBackendIdentifier = async (
     args: BackendIdentifierParameters