Fix data type check in MTRDevice's invokeCommandWithEndpointID.

We were checking two NSStrings for pointer-equality, when we should be testing
for logical equality.

Author: bzbarsky-apple

src/darwin/Framework/CHIP/MTRDevice.mm

@@ -1059,7 +1059,7 @@ - (void)invokeCommandWithEndpointID:(NSNumber *)endpointID
     }
 
     MTRDeviceDataValueDictionary fieldsDataValue = commandFields;
-    if (fieldsDataValue[MTRTypeKey] != MTRStructureValueType) {
+    if (![MTRStructureValueType isEqual:fieldsDataValue[MTRTypeKey]]) {
         MTR_LOG_ERROR("%@ invokeCommandWithEndpointID passed a commandFields (%@) that is not a structure-typed data-value object",
             self, commandFields);
         completion(nil, [MTRError errorForCHIPErrorCode:CHIP_ERROR_INVALID_ARGUMENT]);

src/darwin/Framework/CHIPTests/MTRDeviceTests.m

@@ -1926,6 +1926,51 @@ - (void)test019_MTRDeviceMultipleCommands
     }];
 
     [self waitForExpectations:@[ readFabricLabelExpectation ] timeout:kTimeoutInSeconds];
+
+    // Now test doing the UpdateFabricLabel command but directly via the
+    // MTRDevice API.
+    XCTestExpectation * updateLabelExpectation2 = [self expectationWithDescription:@"Fabric label updated a second time"];
+    // IMPORTANT: commandFields here uses hardcoded strings, not MTR* constants
+    // for the strings, to check for places that are doing string equality wrong.
+    __auto_type * commandFields = @{
+        @"type" : @"Structure",
+        @"value" : @[
+            @{
+                @"contextTag" : @0,
+                @"data" : @ {
+                    @"type" : @"UTF8String",
+                    @"value" : @"Test2",
+                },
+            },
+        ],
+    };
+
+    [device invokeCommandWithEndpointID:@(0)
+                              clusterID:@(MTRClusterIDTypeOperationalCredentialsID)
+                              commandID:@(MTRCommandIDTypeClusterOperationalCredentialsCommandUpdateFabricLabelID)
+                          commandFields:commandFields
+                         expectedValues:nil
+                  expectedValueInterval:nil
+                                  queue:queue
+                             completion:^(NSArray<NSDictionary<NSString *, id> *> * _Nullable values, NSError * _Nullable error) {
+                                 XCTAssertNil(error);
+                                 [updateLabelExpectation2 fulfill];
+                             }];
+
+    [self waitForExpectations:@[ updateLabelExpectation2 ] timeout:kTimeoutInSeconds];
+
+    // And again, make sure our fabric label got updated.
+    readFabricLabelExpectation = [self expectationWithDescription:@"Read fabric label third time"];
+    [baseOpCredsCluster readAttributeFabricsWithParams:nil completion:^(NSArray * _Nullable value, NSError * _Nullable error) {
+        XCTAssertNil(error);
+        XCTAssertNotNil(value);
+        XCTAssertEqual(value.count, 1);
+        MTROperationalCredentialsClusterFabricDescriptorStruct * entry = value[0];
+        XCTAssertEqualObjects(entry.label, @"Test2");
+        [readFabricLabelExpectation fulfill];
+    }];
+
+    [self waitForExpectations:@[ readFabricLabelExpectation ] timeout:kTimeoutInSeconds];
 }
 
 - (void)test020_ReadMultipleAttributes