Add remove method to balancer attributes collection (#2110)

Author: JamesNK

src/Grpc.Net.Client/Balancer/BalancerAttributes.cs

@@ -1,4 +1,4 @@
-#region Copyright notice and license
+#region Copyright notice and license
 
 // Copyright 2019 The gRPC Authors
 //
@@ -113,5 +113,19 @@ public void Set<TValue>(BalancerAttributesKey<TValue> key, TValue value)
     {
         _attributes[key.Key] = value;
     }
+
+    /// <summary>
+    /// Removes the value associated with the specified key.
+    /// </summary>
+    /// <typeparam name="TValue">The value type.</typeparam>
+    /// <param name="key">The key of the value to set.</param>
+    /// <returns>
+    /// <c>true</c> if the element is successfully removed; otherwise, <c>false</c>.
+    /// This method also returns <c>false</c> if key was not found.
+    /// </returns>
+    public bool Remove<TValue>(BalancerAttributesKey<TValue> key)
+    {
+        return _attributes.Remove(key.Key);
+    }
 }
 #endif

test/Grpc.Net.Client.Tests/Balancer/BalancerAttributesTests.cs

@@ -0,0 +1,121 @@
+#region Copyright notice and license
+
+// Copyright 2019 The gRPC Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#endregion
+
+#if SUPPORT_LOAD_BALANCING
+using System;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+using Greet;
+using Grpc.Core;
+using Grpc.Net.Client.Tests.Infrastructure;
+using Grpc.Net.Client.Configuration;
+using Grpc.Tests.Shared;
+using NUnit.Framework;
+using Microsoft.Extensions.Logging.Testing;
+using System.Linq;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.DependencyInjection;
+using System.Net;
+using System.Collections.Generic;
+using Grpc.Net.Client.Balancer.Internal;
+using System.IO;
+using Grpc.Net.Client.Tests.Infrastructure.Balancer;
+using Grpc.Net.Client.Balancer;
+
+namespace Grpc.Net.Client.Tests.Balancer;
+
+[TestFixture]
+public class BalancerAttributesTests
+{
+    [Test]
+    public void TryGetValue_NotFound_ReturnFalse()
+    {
+        // Arrange
+        var key = new BalancerAttributesKey<string>("key");
+
+        var attributes = new BalancerAttributes();
+
+        // Act & Assert
+        Assert.False(attributes.TryGetValue(key, out var value));
+        Assert.Null(value);
+    }
+
+    [Test]
+    public void TryGetValue_Found_ReturnTrue()
+    {
+        // Arrange
+        var key = new BalancerAttributesKey<string>("key");
+
+        var attributes = new BalancerAttributes();
+
+        attributes.Set(key, "value");
+
+        // Act & Assert
+        Assert.True(attributes.TryGetValue(key, out var value));
+        Assert.AreEqual("value", value);
+    }
+
+    [Test]
+    public void Remove_NotFound_ReturnFalse()
+    {
+        // Arrange
+        var key = new BalancerAttributesKey<string>("key");
+
+        var attributes = new BalancerAttributes();
+
+        // Act & Assert
+        Assert.False(attributes.Remove(key));
+    }
+
+    [Test]
+    public void Remove_Found_ReturnTrue()
+    {
+        // Arrange
+        var key = new BalancerAttributesKey<string>("key");
+
+        var attributes = new BalancerAttributes();
+
+        attributes.Set(key, "value");
+
+        // Act & Assert
+        Assert.True(attributes.Remove(key));
+
+        Assert.False(attributes.TryGetValue(key, out var value));
+        Assert.Null(value);
+    }
+
+    [Test]
+    public void Set_Null_NotRemoved()
+    {
+        // Arrange
+        var key = new BalancerAttributesKey<string?>("key");
+
+        var attributes = new BalancerAttributes();
+
+        // Act
+        attributes.Set(key, "value");
+        // Sets value to a null value but still in collection
+        attributes.Set(key, null);
+
+        // Assert
+        Assert.True(attributes.Remove(key));
+    }
+}
+
+#endif