[cloud_functions]Add region support for cloud functions

packages/cloud_functions/android/src/main/java/io/flutter/plugins/firebase/cloudfunctions/cloudfunctions/CloudFunctionsPlugin.java

@@ -32,8 +32,9 @@ public void onMethodCall(MethodCall call, final Result result) {
     switch (call.method) {
       case "CloudFunctions#call":
         String functionName = call.argument("functionName");
+        String region = call.argument("region");
         HttpsCallableReference httpsCallableReference =
-            FirebaseFunctions.getInstance().getHttpsCallable(functionName);
+            FirebaseFunctions.getInstance(region).getHttpsCallable(functionName);
         Map<String, Object> parameters = call.argument("parameters");
         httpsCallableReference
             .call(parameters)

packages/cloud_functions/ios/Classes/CloudFunctionsPlugin.m

@@ -34,37 +34,37 @@ - (instancetype)init {
 - (void)handleMethodCall:(FlutterMethodCall *)call result:(FlutterResult)result {
   if ([@"CloudFunctions#call" isEqualToString:call.method]) {
     NSString *functionName = call.arguments[@"functionName"];
+    NSString *region = call.arguments[@"region"];
     NSObject *parameters = call.arguments[@"parameters"];
-    [[FIRFunctions functions]
-        callFunction:functionName
-          withObject:parameters
-          completion:^(FIRHTTPSCallableResult *callableResult, NSError *error) {
-            if (error) {
-              FlutterError *flutterError;
-              if (error.domain == FIRFunctionsErrorDomain) {
-                NSDictionary *details = [NSMutableDictionary dictionary];
-                [details setValue:[self mapFunctionsErrorCodes:error.code] forKey:@"code"];
-                if (error.localizedDescription != nil) {
-                  [details setValue:error.localizedDescription forKey:@"message"];
+    [[[FIRFunctions functionsForRegion:region] HTTPSCallableWithName:functionName]
+        callWithObject:parameters
+            completion:^(FIRHTTPSCallableResult *callableResult, NSError *error) {
+              if (error) {
+                FlutterError *flutterError;
+                if (error.domain == FIRFunctionsErrorDomain) {
+                  NSDictionary *details = [NSMutableDictionary dictionary];
+                  [details setValue:[self mapFunctionsErrorCodes:error.code] forKey:@"code"];
+                  if (error.localizedDescription != nil) {
+                    [details setValue:error.localizedDescription forKey:@"message"];
+                  }
+                  if (error.userInfo[FIRFunctionsErrorDetailsKey] != nil) {
+                    [details setValue:error.userInfo[FIRFunctionsErrorDetailsKey]
+                               forKey:@"details"];
+                  }
+                  flutterError =
+                      [FlutterError errorWithCode:@"functionsError"
+                                          message:@"Firebase function failed with exception."
+                                          details:details];
+                } else {
+                  flutterError = [FlutterError errorWithCode:nil
+                                                     message:error.localizedDescription
+                                                     details:nil];
                 }
-                if (error.userInfo[FIRFunctionsErrorDetailsKey] != nil) {
-                  [details setValue:error.userInfo[FIRFunctionsErrorDetailsKey] forKey:@"details"];
-                }
-
-                flutterError =
-                    [FlutterError errorWithCode:@"functionsError"
-                                        message:@"Firebase function failed with exception."
-                                        details:details];
+                result(flutterError);
               } else {
-                flutterError = [FlutterError errorWithCode:nil
-                                                   message:error.localizedDescription
-                                                   details:nil];
+                result(callableResult.data);
               }
-              result(flutterError);
-            } else {
-              result(callableResult.data);
-            }
-          }];
+            }];
   } else {
     result(FlutterMethodNotImplemented);
   }

packages/cloud_functions/lib/cloud_functions.dart

@@ -29,16 +29,20 @@ class CloudFunctions {
   /// Executes this Callable HTTPS trigger asynchronously.
   ///
   /// @param functionName The name of the callable function being triggered.
+  /// @param region The region where the callable function being triggered. Default: us-central1.
   /// @param parameters Parameters to be passed to the callable function.
   Future<dynamic> call(
-      {@required String functionName, Map<String, dynamic> parameters}) async {
+      {@required String functionName,
+      String region = 'us-central1',
+      Map<String, dynamic> parameters}) async {
     try {
       final dynamic response =
           // TODO(amirh): remove this on when the invokeMethod update makes it to stable Flutter.
           // https://github.com/flutter/flutter/issues/26431
           // ignore: strong_mode_implicit_dynamic_method
           await channel.invokeMethod('CloudFunctions#call', <String, dynamic>{
         'functionName': functionName,
+        'region': region,
         'parameters': parameters,
       });
       return response;

packages/cloud_functions/test/cloud_functions_test.dart

@@ -32,25 +32,37 @@ void main() {
           .call(functionName: 'qux', parameters: <String, dynamic>{
         'quux': 'quuz',
       });
+      await CloudFunctions.instance
+          .call(functionName: 'buz', region: 'us-east1');
       expect(
         log,
         <Matcher>[
           isMethodCall(
             'CloudFunctions#call',
             arguments: <String, dynamic>{
               'functionName': 'baz',
+              'region': 'us-central1',
               'parameters': null,
             },
           ),
           isMethodCall(
             'CloudFunctions#call',
             arguments: <String, dynamic>{
               'functionName': 'qux',
+              'region': 'us-central1',
               'parameters': <String, dynamic>{
                 'quux': 'quuz',
               },
             },
           ),
+          isMethodCall(
+            'CloudFunctions#call',
+            arguments: <String, dynamic>{
+              'functionName': 'buz',
+              'region': 'us-east1',
+              'parameters': null,
+            },
+          ),
         ],
       );
     });