add dataconnect sdk app setup validation

src/init/features/dataconnect/sdk.ts

@@ -52,7 +52,7 @@
   displayIOSWarning: boolean;
 };
 
 export async function askQuestions(setup: Setup): Promise<void> {
   const info: SdkRequiredInfo = {
     apps: [],
   };
@@ -100,7 +100,7 @@
   setup.featureInfo.dataconnectSdk = info;
 }
 
 export async function chooseApp(): Promise<App[]> {
   let apps = dedupeAppsByPlatformAndDirectory(await detectApps(cwd));
   if (apps.length) {
     logLabeledSuccess(
@@ -148,6 +148,12 @@
     const pickedApps = await checkbox<App>({
       message: "Which apps do you want to set up Data Connect SDKs in?",
       choices,
+      validate: (choices) => {
+        if (choices.length === 0) {
+          return "Please choose at least one app.";
+        }
+        return true;
+      },
     });
     if (!pickedApps || !pickedApps.length) {
       throw new FirebaseError("Command Aborted. Please choose at least one app.");
@@ -157,7 +163,7 @@
   return apps;
 }
 
 export async function actuate(setup: Setup, config: Config) {
   const sdkInfo = setup.featureInfo?.dataconnectSdk;
   if (!sdkInfo) {
     throw new Error("Data Connect SDK feature RequiredInfo is not provided");
@@ -188,7 +194,7 @@
   }
 }
 
 export function initAppCounters(info: SdkRequiredInfo): { [key: string]: number } {
   const counts = {
     num_web_apps: 0,
     num_android_apps: 0,
@@ -219,7 +225,7 @@
   return counts;
 }
 
 async function actuateWithInfo(setup: Setup, config: Config, info: SdkRequiredInfo) {
   if (!info.apps.length) {
     // If no apps is specified, try to detect it again.
     // In `firebase init dataconnect:sdk`, customer may create the app while the command is running.
@@ -261,8 +267,8 @@
       configDir: connectorInfo.directory,
       account,
     });
   } catch (e: any) {
     logLabeledError("dataconnect", `Failed to generate Data Connect SDKs\n${e?.message}`);
   }
 
   logLabeledSuccess(
@@ -301,7 +307,7 @@
  * and short-circuit the prompt.
  *
  * `FDC_CONNECTOR` should have the same `<location>/<serviceId>/<connectorId>`.
  * @param choices
  */
 async function chooseExistingConnector(setup: Setup, config: Config): Promise<ConnectorInfo> {
   const serviceInfos = await loadAll(setup.projectId || "", config);