[Azure.Core] Configurable MaxApplicationIdLength

sdk/core/Azure.Core/api/Azure.Core.net10.0.cs

@@ -391,6 +391,7 @@ protected ClientOptions(Azure.Core.DiagnosticsOptions? diagnostics) { }
         protected ClientOptions(Microsoft.Extensions.Configuration.IConfigurationSection section, Azure.Core.DiagnosticsOptions? diagnostics) { }
         public static Azure.Core.ClientOptions Default { get { throw null; } }
         public Azure.Core.DiagnosticsOptions Diagnostics { get { throw null; } }
+        protected int MaxApplicationIdLength { get { throw null; } set { } }
         public Azure.Core.RetryOptions Retry { get { throw null; } }
         public Azure.Core.Pipeline.HttpPipelinePolicy? RetryPolicy { get { throw null; } set { } }
         public Azure.Core.Pipeline.HttpPipelineTransport Transport { get { throw null; } set { } }

sdk/core/Azure.Core/api/Azure.Core.net462.cs

@@ -381,6 +381,7 @@ protected ClientOptions(Azure.Core.DiagnosticsOptions? diagnostics) { }
         protected ClientOptions(Microsoft.Extensions.Configuration.IConfigurationSection section, Azure.Core.DiagnosticsOptions? diagnostics) { }
         public static Azure.Core.ClientOptions Default { get { throw null; } }
         public Azure.Core.DiagnosticsOptions Diagnostics { get { throw null; } }
+        protected int MaxApplicationIdLength { get { throw null; } set { } }
         public Azure.Core.RetryOptions Retry { get { throw null; } }
         public Azure.Core.Pipeline.HttpPipelinePolicy? RetryPolicy { get { throw null; } set { } }
         public Azure.Core.Pipeline.HttpPipelineTransport Transport { get { throw null; } set { } }

sdk/core/Azure.Core/api/Azure.Core.net472.cs

@@ -381,6 +381,7 @@ protected ClientOptions(Azure.Core.DiagnosticsOptions? diagnostics) { }
         protected ClientOptions(Microsoft.Extensions.Configuration.IConfigurationSection section, Azure.Core.DiagnosticsOptions? diagnostics) { }
         public static Azure.Core.ClientOptions Default { get { throw null; } }
         public Azure.Core.DiagnosticsOptions Diagnostics { get { throw null; } }
+        protected int MaxApplicationIdLength { get { throw null; } set { } }
         public Azure.Core.RetryOptions Retry { get { throw null; } }
         public Azure.Core.Pipeline.HttpPipelinePolicy? RetryPolicy { get { throw null; } set { } }
         public Azure.Core.Pipeline.HttpPipelineTransport Transport { get { throw null; } set { } }

sdk/core/Azure.Core/api/Azure.Core.net8.0.cs

@@ -391,6 +391,7 @@ protected ClientOptions(Azure.Core.DiagnosticsOptions? diagnostics) { }
         protected ClientOptions(Microsoft.Extensions.Configuration.IConfigurationSection section, Azure.Core.DiagnosticsOptions? diagnostics) { }
         public static Azure.Core.ClientOptions Default { get { throw null; } }
         public Azure.Core.DiagnosticsOptions Diagnostics { get { throw null; } }
+        protected int MaxApplicationIdLength { get { throw null; } set { } }
         public Azure.Core.RetryOptions Retry { get { throw null; } }
         public Azure.Core.Pipeline.HttpPipelinePolicy? RetryPolicy { get { throw null; } set { } }
         public Azure.Core.Pipeline.HttpPipelineTransport Transport { get { throw null; } set { } }

sdk/core/Azure.Core/api/Azure.Core.netstandard2.0.cs

@@ -381,6 +381,7 @@ protected ClientOptions(Azure.Core.DiagnosticsOptions? diagnostics) { }
         protected ClientOptions(Microsoft.Extensions.Configuration.IConfigurationSection section, Azure.Core.DiagnosticsOptions? diagnostics) { }
         public static Azure.Core.ClientOptions Default { get { throw null; } }
         public Azure.Core.DiagnosticsOptions Diagnostics { get { throw null; } }
+        protected int MaxApplicationIdLength { get { throw null; } set { } }
         public Azure.Core.RetryOptions Retry { get { throw null; } }
         public Azure.Core.Pipeline.HttpPipelinePolicy? RetryPolicy { get { throw null; } set { } }
         public Azure.Core.Pipeline.HttpPipelineTransport Transport { get { throw null; } set { } }

sdk/core/Azure.Core/src/ClientOptions.cs

@@ -109,6 +109,20 @@ public HttpPipelineTransport Transport
         /// </summary>
         public DiagnosticsOptions Diagnostics { get; }
 
+        /// <summary>
+        /// Gets or sets the maximum allowed length for <see cref="DiagnosticsOptions.ApplicationId"/>.
+        /// </summary>
+        /// <remarks>
+        /// The default value is 24 characters. SDK authors can increase this
+        /// in their derived <see cref="ClientOptions"/> constructor to accommodate longer application identifiers.
+        /// </remarks>
+        /// <exception cref="ArgumentOutOfRangeException">Thrown when the value is less than 24.</exception>
+        protected int MaxApplicationIdLength
+        {
+            get => Diagnostics.MaxApplicationIdLength;
+            set => Diagnostics.MaxApplicationIdLength = value;
+        }
+
         /// <summary>
         /// Gets the client retry options.
         /// </summary>

sdk/core/Azure.Core/src/DiagnosticsOptions.cs

@@ -15,9 +15,9 @@ namespace Azure.Core
     /// </summary>
     public class DiagnosticsOptions
     {
-        private const int MaxApplicationIdLength = 24;
-
         private string? _applicationId;
+        private int _maxApplicationIdLength = DefaultMaxApplicationIdLength;
+        private const int DefaultMaxApplicationIdLength = 24;
 
         /// <summary>
         /// Creates a new instance of <see cref="DiagnosticsOptions"/> with default values.
@@ -102,6 +102,7 @@ internal DiagnosticsOptions(DiagnosticsOptions? diagnosticsOptions)
         {
             if (diagnosticsOptions != null)
             {
+                _maxApplicationIdLength = diagnosticsOptions.MaxApplicationIdLength;
                 ApplicationId = diagnosticsOptions.ApplicationId;
                 IsLoggingEnabled = diagnosticsOptions.IsLoggingEnabled;
                 IsTelemetryEnabled = diagnosticsOptions.IsTelemetryEnabled;
@@ -198,21 +199,38 @@ private static IList<string> GetDefaultLoggedHeaders()
         public IList<string> LoggedQueryParameters { get; internal set; }
 
         /// <summary>
-        /// Gets or sets the value sent as the first part of "User-Agent" headers for all requests issues by this client. Defaults to <see cref="DefaultApplicationId"/>.
+        /// Gets or sets the maximum allowed length for <see cref="ApplicationId"/>.
         /// </summary>
-        public string? ApplicationId
+        /// <remarks>
+        /// The default value is 24 characters. This can be increased to accommodate longer
+        /// application identifiers. Values less than 24 are not permitted.
+        /// </remarks>
+        /// <exception cref="ArgumentOutOfRangeException">Thrown when the value is less than 24.</exception>
+        internal int MaxApplicationIdLength
         {
-            get => _applicationId;
+            get => _maxApplicationIdLength;
             set
             {
-                if (value != null && value.Length > MaxApplicationIdLength)
+                if (value < DefaultMaxApplicationIdLength)
                 {
-                    throw new ArgumentOutOfRangeException(nameof(value), $"{nameof(ApplicationId)} must be shorter than {MaxApplicationIdLength + 1} characters");
+                    throw new ArgumentOutOfRangeException(nameof(value), value, $"{nameof(MaxApplicationIdLength)} must be at least {DefaultMaxApplicationIdLength}.");
                 }
-                _applicationId = value;
+                _maxApplicationIdLength = value;
             }
         }
 
+        /// <summary>
+        /// Gets or sets the value sent as the first part of "User-Agent" headers for all requests issues by this client. Defaults to <see cref="DefaultApplicationId"/>.
+        /// </summary>
+        /// <remarks>
+        /// The length of <see cref="ApplicationId"/> is validated against <see cref="MaxApplicationIdLength"/> when the HTTP pipeline is built.
+        /// </remarks>
+        public string? ApplicationId
+        {
+            get => _applicationId;
+            set => _applicationId = value;
+        }
+
         /// <summary>
         /// Gets or sets the default application id. Default application id would be set on all instances.
         /// </summary>

sdk/core/Azure.Core/src/Pipeline/HttpPipelineBuilder.cs

@@ -218,7 +218,11 @@ void AddNonNullPolicies(HttpPipelinePolicy[] policiesToAdd)
         internal static TelemetryPolicy CreateTelemetryPolicy(ClientOptions options)
         {
             var type = options.GetType();
-            var userAgentValue = new TelemetryDetails(type.Assembly, options.Diagnostics.ApplicationId);
+            var userAgentValue = new TelemetryDetails(
+                type.Assembly,
+                options.Diagnostics.ApplicationId,
+                runtimeInformation: null,
+                maxApplicationIdLength: options.Diagnostics.MaxApplicationIdLength);
             return new TelemetryPolicy(userAgentValue);
         }
     }

sdk/core/Azure.Core/src/TelemetryDetails.cs

@@ -15,7 +15,7 @@ namespace Azure.Core
     /// </summary>
     public class TelemetryDetails
     {
-        private const int MaxApplicationIdLength = 24;
+        private const int DefaultMaxApplicationIdLength = 24;
         private readonly string _userAgent;
 
         /// <summary>
@@ -35,15 +35,15 @@ public class TelemetryDetails
         /// <param name="applicationId">An optional value to be prepended to the <see cref="TelemetryDetails"/>.
         /// This value overrides the behavior of the <see cref="DiagnosticsOptions.ApplicationId"/> property for the <see cref="HttpMessage"/> it is applied to.</param>
         public TelemetryDetails(Assembly assembly, string? applicationId = null)
-            : this(assembly, applicationId, new RuntimeInformationWrapper())
+            : this(assembly, applicationId, new RuntimeInformationWrapper(), maxApplicationIdLength: DefaultMaxApplicationIdLength)
         { }
 
-        internal TelemetryDetails(Assembly assembly, string? applicationId = null, RuntimeInformationWrapper? runtimeInformation = default)
+        internal TelemetryDetails(Assembly assembly, string? applicationId = null, RuntimeInformationWrapper? runtimeInformation = default, int maxApplicationIdLength = DefaultMaxApplicationIdLength)
         {
             Argument.AssertNotNull(assembly, nameof(assembly));
-            if (applicationId?.Length > MaxApplicationIdLength)
+            if (applicationId?.Length > maxApplicationIdLength)
             {
-                throw new ArgumentOutOfRangeException(nameof(applicationId), $"{nameof(applicationId)} must be shorter than {MaxApplicationIdLength + 1} characters");
+                throw new ArgumentOutOfRangeException(nameof(applicationId), $"{nameof(applicationId)} must be shorter than {maxApplicationIdLength + 1} characters. To allow longer values, the SDK library author can increase MaxApplicationIdLength in their ClientOptions-derived constructor.");
             }
 
             Assembly = assembly;

sdk/core/Azure.Core/tests/ClientOptionsTests.cs

@@ -233,10 +233,57 @@ public void AcceptsCustomDiagnosticsOptions([Values(true, false)] bool useCustom
             }
         }
 
+        [Test]
+        public void DefaultMaxApplicationIdLengthIs24()
+        {
+            var options = new TestClientOptionsWithCustomMaxApplicationIdLength();
+            Assert.AreEqual(24, options.GetMaxApplicationIdLength());
+        }
+
+        [Test]
+        public void ApplicationIdExceedingDefaultMaxLengthIsAcceptedByOptions()
+        {
+            var options = new TestClientOptions();
+            var longApplicationId = new string('a', 25);
+
+            options.Diagnostics.ApplicationId = longApplicationId;
+
+            Assert.AreEqual(longApplicationId, options.Diagnostics.ApplicationId);
+        }
+
+        [TestCase(23)]
+        [TestCase(0)]
+        [TestCase(-1)]
+        public void SettingMaxApplicationIdLengthBelowDefaultThrows(int maxLength)
+        {
+            var options = new TestClientOptions();
+
+            var ex = Assert.Throws<ArgumentOutOfRangeException>(() => options.Diagnostics.MaxApplicationIdLength = maxLength);
+            Assert.That(ex.Message, Does.Contain("MaxApplicationIdLength must be at least 24"));
+        }
+
+        [Test]
+        public void SettingMaxApplicationIdLengthToLargeValueSucceeds()
+        {
+            var options = new TestClientOptionsWithCustomMaxApplicationIdLength(1000);
+
+            Assert.AreEqual(1000, options.GetMaxApplicationIdLength());
+        }
+
         private class TestClientOptions : ClientOptions
         {
         }
 
+        private class TestClientOptionsWithCustomMaxApplicationIdLength : ClientOptions
+        {
+            public TestClientOptionsWithCustomMaxApplicationIdLength(int maxApplicationIdLength = 24)
+            {
+                MaxApplicationIdLength = maxApplicationIdLength;
+            }
+
+            public int GetMaxApplicationIdLength() => MaxApplicationIdLength;
+        }
+
         private class TestDiagnosticsOptions : DiagnosticsOptions
         {
             public int MeExtraProperty { get; set; }

sdk/core/Azure.Core/tests/HttpPipelineBuilderTest.cs

@@ -174,6 +174,44 @@ public async Task VersionDoesntHaveCommitHash()
                                  Regex.Escape($" ({RuntimeInformation.FrameworkDescription}; {RuntimeInformation.OSDescription})"), userAgent);
         }
 
+        [Test]
+        public async Task CreateTelemetryPolicyHonorsCustomMaxApplicationIdLength()
+        {
+            var longApplicationId = new string('a', 50);
+            var options = new TestOptionsWithCustomMaxApplicationIdLength(50);
+            options.Diagnostics.ApplicationId = longApplicationId;
+
+            var transport = new MockTransport(new MockResponse(200));
+            var telemetryPolicy = HttpPipelineBuilder.CreateTelemetryPolicy(options);
+
+            await SendGetRequest(transport, telemetryPolicy);
+
+            Assert.True(transport.SingleRequest.TryGetHeader("User-Agent", out var userAgent));
+            StringAssert.StartsWith(longApplicationId + " ", userAgent);
+        }
+
+        [Test]
+        public void ApplicationIdExceedingDefaultMaxLengthThrowsAtPipelineBuild()
+        {
+            var options = new TestOptions();
+            options.Diagnostics.ApplicationId = new string('a', 25);
+
+            var ex = Assert.Throws<ArgumentOutOfRangeException>(() => HttpPipelineBuilder.Build(options));
+            Assert.That(ex.Message, Does.Contain("applicationId must be shorter than 25 characters"));
+            Assert.That(ex.Message, Does.Contain("MaxApplicationIdLength"));
+        }
+
+        [Test]
+        public void ApplicationIdExceedingCustomMaxLengthThrowsAtPipelineBuild()
+        {
+            var options = new TestOptionsWithCustomMaxApplicationIdLength(50);
+            options.Diagnostics.ApplicationId = new string('a', 51);
+
+            var ex = Assert.Throws<ArgumentOutOfRangeException>(() => HttpPipelineBuilder.Build(options));
+            Assert.That(ex.Message, Does.Contain("applicationId must be shorter than 51 characters"));
+            Assert.That(ex.Message, Does.Contain("MaxApplicationIdLength"));
+        }
+
         [Test]
         public async Task CustomClientRequestIdAvailableInPerCallPolicies()
         {
@@ -338,6 +376,15 @@ public TestOptions()
             }
         }
 
+        private class TestOptionsWithCustomMaxApplicationIdLength : ClientOptions
+        {
+            public TestOptionsWithCustomMaxApplicationIdLength(int maxApplicationIdLength)
+            {
+                MaxApplicationIdLength = maxApplicationIdLength;
+                Retry.Delay = TimeSpan.Zero;
+            }
+        }
+
         private class CounterPolicy : HttpPipelineSynchronousPolicy
         {
             public override void OnSendingRequest(HttpMessage message)

sdk/core/Azure.Core/tests/TelemetryDetailsTests.cs

@@ -52,6 +52,44 @@ public void CtorPopulatesProperties([Values(null, appId)] string applicationId)
             Assert.AreEqual(applicationId, target.ApplicationId);
         }
 
+        [Test]
+        public void ApplicationIdExceedingDefaultMaxLengthThrows()
+        {
+            var longApplicationId = new string('a', 25);
+
+            var ex = Assert.Throws<ArgumentOutOfRangeException>(() => new TelemetryDetails(typeof(TelemetryDetailsTests).Assembly, longApplicationId));
+            Assert.That(ex.Message, Does.Contain("applicationId must be shorter than 25 characters"));
+        }
+
+        [Test]
+        public void ApplicationIdAtDefaultMaxLengthSucceeds()
+        {
+            var applicationId = new string('a', 24);
+
+            var target = new TelemetryDetails(typeof(TelemetryDetailsTests).Assembly, applicationId);
+
+            Assert.AreEqual(applicationId, target.ApplicationId);
+        }
+
+        [Test]
+        public void CustomMaxApplicationIdLengthAllowsLongerApplicationId()
+        {
+            var longApplicationId = new string('a', 50);
+
+            var target = new TelemetryDetails(typeof(TelemetryDetailsTests).Assembly, longApplicationId, maxApplicationIdLength: 50);
+
+            Assert.AreEqual(longApplicationId, target.ApplicationId);
+        }
+
+        [Test]
+        public void CustomMaxApplicationIdLengthStillEnforcesLimit()
+        {
+            var tooLongApplicationId = new string('a', 51);
+
+            var ex = Assert.Throws<ArgumentOutOfRangeException>(() => new TelemetryDetails(typeof(TelemetryDetailsTests).Assembly, tooLongApplicationId, maxApplicationIdLength: 50));
+            Assert.That(ex.Message, Does.Contain("applicationId must be shorter than 51 characters"));
+        }
+
         [Test]
         public void AppliesToMessage()
         {

sdk/core/Azure.Core/tests/TelemetryPolicyTests.cs

@@ -46,13 +46,6 @@ public async Task ApplicationIdIsIncluded()
             StringAssert.StartsWith("application-id ", userAgent);
         }
 
-        [Test]
-        public void ApplicationIdLimitedTo24Chars()
-        {
-            var options = new DiagnosticsOptions();
-            Assert.Throws<ArgumentOutOfRangeException>(() => options.ApplicationId = "0123456789012345678912345");
-        }
-
         private class TestOptions : ClientOptions
         { }
     }