From f8e203b4fbe3a5108131bdf82202d3c288b0379b Mon Sep 17 00:00:00 2001
From: Kundok Park <97262718+kpark-apple@users.noreply.github.com>
Date: Thu, 10 Mar 2022 07:58:49 -0800
Subject: [PATCH] Fix XPC connection failure handling (#16063)

for Darwin CHIPDeviceController.
---
 .../CHIP/CHIPDeviceControllerXPCConnection.m  |  1 +
 .../CHIPTests/CHIPXPCProtocolTests.m          | 35 +++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/src/darwin/Framework/CHIP/CHIPDeviceControllerXPCConnection.m b/src/darwin/Framework/CHIP/CHIPDeviceControllerXPCConnection.m
index 2af67652b89f82..ea34191e7081aa 100644
--- a/src/darwin/Framework/CHIP/CHIPDeviceControllerXPCConnection.m
+++ b/src/darwin/Framework/CHIP/CHIPDeviceControllerXPCConnection.m
@@ -93,6 +93,7 @@ - (void)getProxyHandleWithCompletion:(void (^)(dispatch_queue_t queue,
             if (!xpcConnection) {
                 CHIP_LOG_ERROR("Cannot connect to XPC server for remote controller");
                 completion(self.workQueue, nil);
+                return;
             }
             xpcConnection.remoteObjectInterface = self.remoteDeviceServerProtocol;
             xpcConnection.exportedInterface = self.remoteDeviceClientProtocol;
diff --git a/src/darwin/Framework/CHIPTests/CHIPXPCProtocolTests.m b/src/darwin/Framework/CHIPTests/CHIPXPCProtocolTests.m
index 76177624dc08b6..fea62527b4eecd 100644
--- a/src/darwin/Framework/CHIPTests/CHIPXPCProtocolTests.m
+++ b/src/darwin/Framework/CHIPTests/CHIPXPCProtocolTests.m
@@ -1823,4 +1823,39 @@ - (void)testReadAttributeCacheFailure
     XCTAssertNil(_xpcConnection);
 }
 
+- (void)testXPCConnectionFailure
+{
+    uint64_t myNodeId = 9876543210;
+    NSUInteger myEndpointId = 100;
+    NSUInteger myClusterId = 200;
+    NSUInteger myAttributeId = 300;
+    XCTestExpectation * responseExpectation = [self expectationWithDescription:@"Read response received"];
+
+    // Test with a device controller which wouldn't connect to XPC listener successfully
+    __auto_type failingDeviceController = [CHIPDeviceController sharedControllerWithId:_controllerUUID
+                                                                       xpcConnectBlock:^NSXPCConnection * {
+                                                                           return nil;
+                                                                       }];
+
+    [failingDeviceController getConnectedDevice:myNodeId
+                                          queue:dispatch_get_main_queue()
+                              completionHandler:^(CHIPDevice * _Nullable device, NSError * _Nullable error) {
+                                  XCTAssertNotNil(device);
+                                  XCTAssertNil(error);
+                                  NSLog(@"Device acquired. Reading...");
+                                  [device readAttributeWithEndpointId:myEndpointId
+                                                            clusterId:myClusterId
+                                                          attributeId:myAttributeId
+                                                          clientQueue:dispatch_get_main_queue()
+                                                           completion:^(id _Nullable value, NSError * _Nullable error) {
+                                                               NSLog(@"Read value: %@", value);
+                                                               XCTAssertNil(value);
+                                                               XCTAssertNotNil(error);
+                                                               [responseExpectation fulfill];
+                                                           }];
+                              }];
+
+    [self waitForExpectations:@[ responseExpectation ] timeout:kTimeoutInSeconds];
+}
+
 @end