Added the DeploymentLabelEnricher to be shared between projects. (#322)

Author: agr

src/NuGet.Services.Logging/DeploymentLabelEnricher.cs

@@ -0,0 +1,36 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using Microsoft.ApplicationInsights.Channel;
+using Microsoft.ApplicationInsights.DataContracts;
+using Microsoft.ApplicationInsights.Extensibility;
+
+namespace NuGet.Services.Logging
+{
+    public class DeploymentLabelEnricher : ITelemetryInitializer
+    {
+        private const string DeploymentLabel = "DeploymentLabel";
+        private readonly string _deploymentLabel;
+
+        public DeploymentLabelEnricher(string deploymentLabel)
+        {
+            _deploymentLabel = deploymentLabel ?? throw new ArgumentNullException(nameof(deploymentLabel));
+        }
+
+        public void Initialize(ITelemetry telemetry)
+        {
+            if (!(telemetry is ISupportProperties itemTelemetry))
+            {
+                return;
+            }
+
+            if (itemTelemetry.Properties.ContainsKey(DeploymentLabel))
+            {
+                return;
+            }
+
+            itemTelemetry.Properties.Add(DeploymentLabel, _deploymentLabel);
+        }
+    }
+}

src/NuGet.Services.Logging/NuGet.Services.Logging.csproj

@@ -50,6 +50,7 @@
   <ItemGroup>
     <Compile Include="ApplicationInsights.cs" />
     <Compile Include="ApplicationInsightsConfiguration.cs" />
+    <Compile Include="DeploymentLabelEnricher.cs" />
     <Compile Include="DurationMetric.cs" />
     <Compile Include="ExceptionTelemetryProcessor.cs" />
     <Compile Include="LoggingSetup.cs" />

tests/NuGet.Services.Logging.Tests/DeploymentLabelEnricherTests.cs

@@ -0,0 +1,80 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Collections.Generic;
+using Microsoft.ApplicationInsights.Channel;
+using Microsoft.ApplicationInsights.DataContracts;
+using Moq;
+using Xunit;
+
+namespace NuGet.Services.Logging.Tests
+{
+    public class DeploymentLabelEnricherTests
+    {
+        const string DeploymentLabel = "TestDeploymentLabel";
+        const string DeploymentLabelPropertyName = "DeploymentLabel";
+
+        private DeploymentLabelEnricher Target { get; }
+
+        [Fact]
+        public void ConstructorThrowsWhenDeploymentLabelNull()
+        {
+            var ex = Assert.Throws<ArgumentNullException>(() => new DeploymentLabelEnricher(deploymentLabel: null));
+            Assert.Equal("deploymentLabel", ex.ParamName);
+        }
+
+        [Fact]
+        public void WorksWithAnyITelemetry()
+        {
+            var telemetryMock = new Mock<ITelemetry>();
+            var ex = Record.Exception(() => Target.Initialize(telemetryMock.Object));
+            Assert.Null(ex);
+        }
+
+        [Fact]
+        public void DoesNotOverwriteExistingLabel()
+        {
+            var telemetryMock = new Mock<ITelemetry>();
+            var propertiesMock = new Mock<IDictionary<string, string>>();
+            telemetryMock
+                .As<ISupportProperties>()
+                .SetupGet(sp => sp.Properties)
+                .Returns(propertiesMock.Object);
+            propertiesMock
+                .Setup(p => p.ContainsKey(DeploymentLabelPropertyName))
+                .Returns(true);
+            Target.Initialize(telemetryMock.Object);
+
+            propertiesMock
+                .Verify(p => p.ContainsKey(DeploymentLabelPropertyName), Times.Once);
+            propertiesMock
+                .VerifyNoOtherCalls();
+        }
+
+        [Fact]
+        public void StoresDeploymentLabel()
+        {
+            var telemetryMock = new Mock<ITelemetry>();
+            var propertiesMock = new Mock<IDictionary<string, string>>();
+            telemetryMock
+                .As<ISupportProperties>()
+                .SetupGet(sp => sp.Properties)
+                .Returns(propertiesMock.Object);
+            propertiesMock
+                .Setup(p => p.ContainsKey(DeploymentLabelPropertyName))
+                .Returns(false);
+            Target.Initialize(telemetryMock.Object);
+
+            propertiesMock
+                .Verify(p => p.ContainsKey(DeploymentLabelPropertyName), Times.Once);
+            propertiesMock
+                .Verify(p => p.Add(DeploymentLabelPropertyName, DeploymentLabel), Times.Once);
+        }
+
+        public DeploymentLabelEnricherTests()
+        {
+            Target = new DeploymentLabelEnricher(DeploymentLabel);
+        }
+    }
+}

tests/NuGet.Services.Logging.Tests/NuGet.Services.Logging.Tests.csproj

@@ -54,6 +54,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="ApplicationInsightsTests.cs" />
+    <Compile Include="DeploymentLabelEnricherTests.cs" />
     <Compile Include="ExceptionTelemetryProcessorTests.cs" />
     <Compile Include="LoggingSetupTests.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />