fix(schematics): warn when ng add setup runs with no features selected

src/schematics/setup/index.ts

@@ -21,7 +21,7 @@ import {
   createFirestoreStarterFiles,
   setDefaultProjectInFirebaseRc,
 } from './firebaseConfigs';
-import { appPrompt, featuresPrompt, projectPrompt, userPrompt } from './prompts';
+import { appPrompt, featuresPrompt, featuresPromptMessage, projectPrompt, userPrompt } from './prompts';
 
 // FirebaseOptions keys — apps.sdkconfig responses include management-API extras that initializeApp() rejects.
 const firebaseOptionsKeys = [
@@ -67,7 +67,14 @@ export const ngAddSetupProject = (
 
   const features = await featuresPrompt();
 
-  if (features.length > 0) {
+  if (features.length === 0) {
+    context.logger.warn(
+      'No features were selected, so there is nothing to set up. ' +
+      `At the "${featuresPromptMessage}" prompt, use the arrow keys to move, ` +
+      'press Space to select each feature you want, then Enter to confirm. ' +
+      'Re-run ng add @angular/fire to try again.'
+    );
+  } else {
 
     const firebaseTools = await getFirebaseTools();
 

src/schematics/setup/prompts.ts

@@ -79,12 +79,14 @@ type Prompt = <K extends string, U= unknown>(questions: { name: K, source: (...a
 const autocomplete: Prompt = (questions) => inquirer.prompt(questions);
 
 
+export const featuresPromptMessage = 'What features would you like to setup?';
+
 export const featuresPrompt = async (): Promise<FEATURES[]> => {
   const { features } = await inquirer.prompt({
     type: 'checkbox',
     name: 'features',
     choices: featureOptions,
-    message: 'What features would you like to setup?',
+    message: featuresPromptMessage,
     default: [],
   }) as { features: FEATURES[] };
   return features;