feat: add http onCall triggers (#8)

Author: Lyokone

example/basic/lib/main.dart

@@ -34,6 +34,75 @@ final isProduction = defineBoolean(
 
 void main(List<String> args) {
   fireUp(args, (firebase) {
+    // ==========================================================================
+    // HTTPS Callable Functions (onCall / onCallWithData)
+    // ==========================================================================
+
+    // Basic callable function - untyped data
+    firebase.https.onCall(
+      name: 'greet',
+      (request, response) async {
+        final data = request.data as Map<String, dynamic>?;
+        final name = data?['name'] ?? 'World';
+        return CallableResult({'message': 'Hello, $name!'});
+      },
+    );
+
+    // Callable function with typed data using fromJson
+    firebase.https.onCallWithData<GreetRequest, GreetResponse>(
+      name: 'greetTyped',
+      fromJson: GreetRequest.fromJson,
+      (request, response) async {
+        return GreetResponse(message: 'Hello, ${request.data.name}!');
+      },
+    );
+
+    // Callable function demonstrating error handling
+    firebase.https.onCall(
+      name: 'divide',
+      (request, response) async {
+        final data = request.data as Map<String, dynamic>?;
+        final a = (data?['a'] as num?)?.toDouble();
+        final b = (data?['b'] as num?)?.toDouble();
+
+        if (a == null || b == null) {
+          throw InvalidArgumentError('Both "a" and "b" are required');
+        }
+
+        if (b == 0) {
+          throw FailedPreconditionError('Cannot divide by zero');
+        }
+
+        return CallableResult({'result': a / b});
+      },
+    );
+
+    // Callable function with streaming support
+    firebase.https.onCall(
+      name: 'countdown',
+      options: const CallableOptions(
+        heartBeatIntervalSeconds: HeartBeatIntervalSeconds(5),
+      ),
+      (request, response) async {
+        final data = request.data as Map<String, dynamic>?;
+        final start = (data?['start'] as num?)?.toInt() ?? 10;
+
+        // Stream countdown if client supports it
+        if (request.acceptsStreaming) {
+          for (var i = start; i >= 0; i--) {
+            await response.sendChunk({'count': i});
+            await Future<void>.delayed(const Duration(milliseconds: 100));
+          }
+        }
+
+        return CallableResult({'message': 'Countdown complete!'});
+      },
+    );
+
+    // ==========================================================================
+    // HTTPS onRequest Functions
+    // ==========================================================================
+
     // HTTPS onRequest example - using parameterized configuration
     firebase.https.onRequest(
       name: 'helloWorld',
@@ -251,3 +320,29 @@ void main(List<String> args) {
     print('Functions registered successfully!');
   });
 }
+
+// =============================================================================
+// Data classes for typed callable functions
+// =============================================================================
+
+/// Request data for the greetTyped callable function.
+class GreetRequest {
+  GreetRequest({required this.name});
+
+  factory GreetRequest.fromJson(Map<String, dynamic> json) {
+    return GreetRequest(name: json['name'] as String? ?? 'World');
+  }
+
+  final String name;
+
+  Map<String, dynamic> toJson() => {'name': name};
+}
+
+/// Response data for the greetTyped callable function.
+class GreetResponse {
+  GreetResponse({required this.message});
+
+  final String message;
+
+  Map<String, dynamic> toJson() => {'message': message};
+}

example/nodejs_reference/index.js

@@ -4,7 +4,7 @@
  * generates compatible functions.yaml output.
  */
 
-const { onRequest } = require("firebase-functions/v2/https");
+const { onRequest, onCall, HttpsError } = require("firebase-functions/v2/https");
 const { onMessagePublished } = require("firebase-functions/v2/pubsub");
 const { onDocumentCreated, onDocumentUpdated, onDocumentDeleted, onDocumentWritten } = require("firebase-functions/v2/firestore");
 const { onValueCreated, onValueUpdated, onValueDeleted, onValueWritten } = require("firebase-functions/v2/database");
@@ -33,6 +33,53 @@ const isProduction = defineBoolean("IS_PRODUCTION", {
   description: "Whether this is a production deployment",
 });
 
+// =============================================================================
+// HTTPS Callable Functions (onCall)
+// =============================================================================
+
+// Basic callable function - untyped data
+exports.greet = onCall((request) => {
+  const name = request.data?.name ?? "World";
+  return { message: `Hello, ${name}!` };
+});
+
+// Callable function with typed data (same manifest structure as untyped)
+exports.greetTyped = onCall((request) => {
+  const name = request.data?.name ?? "World";
+  return { message: `Hello, ${name}!` };
+});
+
+// Callable function demonstrating error handling
+exports.divide = onCall((request) => {
+  const a = request.data?.a;
+  const b = request.data?.b;
+
+  if (a === undefined || b === undefined) {
+    throw new HttpsError("invalid-argument", 'Both "a" and "b" are required');
+  }
+
+  if (b === 0) {
+    throw new HttpsError("failed-precondition", "Cannot divide by zero");
+  }
+
+  return { result: a / b };
+});
+
+// Callable function with streaming support
+exports.countdown = onCall(
+  {
+    // heartbeatSeconds is a runtime option, not in manifest
+  },
+  (request) => {
+    // Streaming is handled at runtime, not in manifest
+    return { message: "Countdown complete!" };
+  }
+);
+
+// =============================================================================
+// HTTPS onRequest Functions
+// =============================================================================
+
 // HTTPS onRequest example - using parameterized configuration
 exports.helloWorld = onRequest(
   {