Add LLM environment detection telemetry data point with rule-based detection system and multiple environment support

src/Cli/dotnet/Telemetry/CIEnvironmentDetectorForTelemetry.cs

@@ -1,73 +1,50 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-#nullable disable
+using System;
+using System.Linq;
 
 namespace Microsoft.DotNet.Cli.Telemetry;
 
 internal class CIEnvironmentDetectorForTelemetry : ICIEnvironmentDetector
 {
-    // Systems that provide boolean values only, so we can simply parse and check for true
-    private static readonly string[] _booleanVariables = [
-        // Azure Pipelines - https://docs.microsoft.com/en-us/azure/devops/pipelines/build/variables#system-variables-devops-services
-        "TF_BUILD",
-        // GitHub Actions - https://docs.github.com/en/actions/learn-github-actions/environment-variables#default-environment-variables
-        "GITHUB_ACTIONS",
-        // AppVeyor - https://www.appveyor.com/docs/environment-variables/
-        "APPVEYOR",
-        // A general-use flag - Many of the major players support this: AzDo, GitHub, GitLab, AppVeyor, Travis CI, CircleCI.
-        // Given this, we could potentially remove all of these other options?
-        "CI",
-        // Travis CI - https://docs.travis-ci.com/user/environment-variables/#default-environment-variables
-        "TRAVIS",
-        // CircleCI - https://circleci.com/docs/2.0/env-vars/#built-in-environment-variables
-        "CIRCLECI",
-    ];
-
-    // Systems where every variable must be present and not-null before returning true
-    private static readonly string[][] _allNotNullVariables = [
+    private static readonly EnvironmentDetectionRule[] _detectionRules = [
+        // Systems that provide boolean values only, so we can simply parse and check for true
+        new BooleanEnvironmentRule(
+            // Azure Pipelines - https://docs.microsoft.com/en-us/azure/devops/pipelines/build/variables#system-variables-devops-services
+            "TF_BUILD",
+            // GitHub Actions - https://docs.github.com/en/actions/learn-github-actions/environment-variables#default-environment-variables
+            "GITHUB_ACTIONS",
+            // AppVeyor - https://www.appveyor.com/docs/environment-variables/
+            "APPVEYOR",
+            // A general-use flag - Many of the major players support this: AzDo, GitHub, GitLab, AppVeyor, Travis CI, CircleCI.
+            // Given this, we could potentially remove all of these other options?
+            "CI",
+            // Travis CI - https://docs.travis-ci.com/user/environment-variables/#default-environment-variables
+            "TRAVIS",
+            // CircleCI - https://circleci.com/docs/2.0/env-vars/#built-in-environment-variables
+            "CIRCLECI"
+        ),
+
+        // Systems where every variable must be present and not-null before returning true
         // AWS CodeBuild - https://docs.aws.amazon.com/codebuild/latest/userguide/build-env-ref-env-vars.html
-        ["CODEBUILD_BUILD_ID", "AWS_REGION"],
+        new AllPresentEnvironmentRule("CODEBUILD_BUILD_ID", "AWS_REGION"),
         // Jenkins - https://github.com/jenkinsci/jenkins/blob/master/core/src/main/resources/jenkins/model/CoreEnvironmentContributor/buildEnv.groovy
-        ["BUILD_ID", "BUILD_URL"],
+        new AllPresentEnvironmentRule("BUILD_ID", "BUILD_URL"),
         // Google Cloud Build - https://cloud.google.com/build/docs/configuring-builds/substitute-variable-values#using_default_substitutions
-        ["BUILD_ID", "PROJECT_ID"]
-    ];
-
-    // Systems where the variable must be present and not-null
-    private static readonly string[] _ifNonNullVariables = [
-        // TeamCity - https://www.jetbrains.com/help/teamcity/predefined-build-parameters.html#Predefined+Server+Build+Parameters
-        "TEAMCITY_VERSION",
-        // JetBrains Space - https://www.jetbrains.com/help/space/automation-environment-variables.html#general
-        "JB_SPACE_API_URL"
+        new AllPresentEnvironmentRule("BUILD_ID", "PROJECT_ID"),
+
+        // Systems where the variable must be present and not-null
+        new AnyPresentEnvironmentRule(
+            // TeamCity - https://www.jetbrains.com/help/teamcity/predefined-build-parameters.html#Predefined+Server+Build+Parameters
+            "TEAMCITY_VERSION",
+            // JetBrains Space - https://www.jetbrains.com/help/space/automation-environment-variables.html#general
+            "JB_SPACE_API_URL"
+        )
     ];
 
     public bool IsCIEnvironment()
     {
-        foreach (var booleanVariable in _booleanVariables)
-        {
-            if (bool.TryParse(Environment.GetEnvironmentVariable(booleanVariable), out bool envVar) && envVar)
-            {
-                return true;
-            }
-        }
-
-        foreach (var variables in _allNotNullVariables)
-        {
-            if (variables.All((variable) => !string.IsNullOrEmpty(Environment.GetEnvironmentVariable(variable))))
-            {
-                return true;
-            }
-        }
-
-        foreach (var variable in _ifNonNullVariables)
-        {
-            if (!string.IsNullOrEmpty(Environment.GetEnvironmentVariable(variable)))
-            {
-                return true;
-            }
-        }
-
-        return false;
+        return _detectionRules.Any(rule => rule.IsMatch());
     }
 }

src/Cli/dotnet/Telemetry/EnvironmentDetectionRule.cs

@@ -0,0 +1,103 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Microsoft.DotNet.Cli.Telemetry;
+
+/// <summary>
+/// Base class for environment detection rules that can be evaluated against environment variables.
+/// </summary>
+internal abstract class EnvironmentDetectionRule
+{
+    /// <summary>
+    /// Evaluates the rule against the current environment.
+    /// </summary>
+    /// <returns>True if the rule matches the current environment; otherwise, false.</returns>
+    public abstract bool IsMatch();
+}
+
+/// <summary>
+/// Rule that matches when any of the specified environment variables is set to "true".
+/// </summary>
+internal class BooleanEnvironmentRule : EnvironmentDetectionRule
+{
+    private readonly string[] _variables;
+
+    public BooleanEnvironmentRule(params string[] variables)
+    {
+        _variables = variables ?? throw new ArgumentNullException(nameof(variables));
+    }
+
+    public override bool IsMatch()
+    {
+        return _variables.Any(variable => 
+            bool.TryParse(Environment.GetEnvironmentVariable(variable), out bool value) && value);
+    }
+}
+
+/// <summary>
+/// Rule that matches when all specified environment variables are present and not null/empty.
+/// </summary>
+internal class AllPresentEnvironmentRule : EnvironmentDetectionRule
+{
+    private readonly string[] _variables;
+
+    public AllPresentEnvironmentRule(params string[] variables)
+    {
+        _variables = variables ?? throw new ArgumentNullException(nameof(variables));
+    }
+
+    public override bool IsMatch()
+    {
+        return _variables.All(variable => !string.IsNullOrEmpty(Environment.GetEnvironmentVariable(variable)));
+    }
+}
+
+/// <summary>
+/// Rule that matches when any of the specified environment variables is present and not null/empty.
+/// </summary>
+internal class AnyPresentEnvironmentRule : EnvironmentDetectionRule
+{
+    private readonly string[] _variables;
+
+    public AnyPresentEnvironmentRule(params string[] variables)
+    {
+        _variables = variables ?? throw new ArgumentNullException(nameof(variables));
+    }
+
+    public override bool IsMatch()
+    {
+        return _variables.Any(variable => !string.IsNullOrEmpty(Environment.GetEnvironmentVariable(variable)));
+    }
+}
+
+/// <summary>
+/// Rule that matches when any of the specified environment variables is present and not null/empty,
+/// and returns the associated result value.
+/// </summary>
+/// <typeparam name="T">The type of the result value.</typeparam>
+internal class EnvironmentDetectionRuleWithResult<T> where T : class
+{
+    private readonly string[] _variables;
+    private readonly T _result;
+
+    public EnvironmentDetectionRuleWithResult(T result, params string[] variables)
+    {
+        _variables = variables ?? throw new ArgumentNullException(nameof(variables));
+        _result = result ?? throw new ArgumentNullException(nameof(result));
+    }
+
+    /// <summary>
+    /// Evaluates the rule and returns the result if matched.
+    /// </summary>
+    /// <returns>The result value if the rule matches; otherwise, null.</returns>
+    public T? GetResult()
+    {
+        return _variables.Any(variable => !string.IsNullOrEmpty(Environment.GetEnvironmentVariable(variable))) 
+            ? _result 
+            : null;
+    }
+}

src/Cli/dotnet/Telemetry/ICIEnvironmentDetector.cs

@@ -1,8 +1,6 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-#nullable disable
-
 namespace Microsoft.DotNet.Cli.Telemetry;
 
 internal interface ICIEnvironmentDetector

src/Cli/dotnet/Telemetry/ILLMEnvironmentDetector.cs

@@ -0,0 +1,9 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.DotNet.Cli.Telemetry;
+
+internal interface ILLMEnvironmentDetector
+{
+    string? GetLLMEnvironment();
+}

src/Cli/dotnet/Telemetry/LLMEnvironmentDetectorForTelemetry.cs

@@ -0,0 +1,23 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Linq;
+
+namespace Microsoft.DotNet.Cli.Telemetry;
+
+internal class LLMEnvironmentDetectorForTelemetry : ILLMEnvironmentDetector
+{
+    private static readonly EnvironmentDetectionRuleWithResult<string>[] _detectionRules = [
+        // Claude Code
+        new EnvironmentDetectionRuleWithResult<string>("claude", "CLAUDECODE"),
+        // Cursor AI
+        new EnvironmentDetectionRuleWithResult<string>("cursor", "CURSOR_EDITOR")
+    ];
+
+    public string? GetLLMEnvironment()
+    {
+        var results = _detectionRules.Select(r => r.GetResult()).Where(r => r != null).ToArray();
+        return results.Length > 0 ? string.Join(", ", results) : null;
+    }
+}

src/Cli/dotnet/Telemetry/TelemetryCommonProperties.cs

@@ -18,10 +18,12 @@ internal class TelemetryCommonProperties(
     Func<string> getDeviceId = null,
     IDockerContainerDetector dockerContainerDetector = null,
     IUserLevelCacheWriter userLevelCacheWriter = null,
-    ICIEnvironmentDetector ciEnvironmentDetector = null)
+    ICIEnvironmentDetector ciEnvironmentDetector = null,
+    ILLMEnvironmentDetector llmEnvironmentDetector = null)
 {
     private readonly IDockerContainerDetector _dockerContainerDetector = dockerContainerDetector ?? new DockerContainerDetectorForTelemetry();
     private readonly ICIEnvironmentDetector _ciEnvironmentDetector = ciEnvironmentDetector ?? new CIEnvironmentDetectorForTelemetry();
+    private readonly ILLMEnvironmentDetector _llmEnvironmentDetector = llmEnvironmentDetector ?? new LLMEnvironmentDetectorForTelemetry();
     private readonly Func<string> _getCurrentDirectory = getCurrentDirectory ?? Directory.GetCurrentDirectory;
     private readonly Func<string, string> _hasher = hasher ?? Sha256Hasher.Hash;
     private readonly Func<string> _getMACAddress = getMACAddress ?? MacAddressGetter.GetMacAddress;
@@ -47,6 +49,7 @@ internal class TelemetryCommonProperties(
     private const string SessionId = "SessionId";
 
     private const string CI = "Continuous Integration";
+    private const string LLM = "llm";
 
     private const string TelemetryProfileEnvironmentVariable = "DOTNET_CLI_TELEMETRY_PROFILE";
     private const string CannotFindMacAddress = "Unknown";
@@ -67,6 +70,7 @@ public FrozenDictionary<string, string> GetTelemetryCommonProperties(string curr
             {TelemetryProfile, Environment.GetEnvironmentVariable(TelemetryProfileEnvironmentVariable)},
             {DockerContainer, _userLevelCacheWriter.RunWithCache(IsDockerContainerCacheKey, () => _dockerContainerDetector.IsDockerContainer().ToString("G") )},
             {CI, _ciEnvironmentDetector.IsCIEnvironment().ToString() },
+            {LLM, _llmEnvironmentDetector.GetLLMEnvironment() },
             {CurrentPathHash, _hasher(_getCurrentDirectory())},
             {MachineIdOld, _userLevelCacheWriter.RunWithCache(MachineIdCacheKey, GetMachineId)},
             // we don't want to recalcuate a new id for every new SDK version. Reuse the same path across versions.

test/dotnet.Tests/TelemetryCommonPropertiesTests.cs

@@ -163,6 +163,13 @@ public void TelemetryCommonPropertiesShouldContainLibcReleaseAndVersion()
             }
         }
 
+        [Fact]
+        public void TelemetryCommonPropertiesShouldReturnIsLLMDetection()
+        {
+            var unitUnderTest = new TelemetryCommonProperties(getMACAddress: () => null, userLevelCacheWriter: new NothingCache());
+            unitUnderTest.GetTelemetryCommonProperties("dummySessionId")["llm"].Should().BeOneOf("claude", null);
+        }
+
         [Theory]
         [MemberData(nameof(CITelemetryTestCases))]
         public void CanDetectCIStatusForEnvVars(Dictionary<string, string> envVars, bool expected)
@@ -184,6 +191,27 @@ public void CanDetectCIStatusForEnvVars(Dictionary<string, string> envVars, bool
             }
         }
 
+        [Theory]
+        [MemberData(nameof(LLMTelemetryTestCases))]
+        public void CanDetectLLMStatusForEnvVars(Dictionary<string, string> envVars, string expected)
+        {
+            try
+            {
+                foreach (var (key, value) in envVars)
+                {
+                    Environment.SetEnvironmentVariable(key, value);
+                }
+                new LLMEnvironmentDetectorForTelemetry().GetLLMEnvironment().Should().Be(expected);
+            }
+            finally
+            {
+                foreach (var (key, value) in envVars)
+                {
+                    Environment.SetEnvironmentVariable(key, null);
+                }
+            }
+        }
+
         [Theory]
         [InlineData("dummySessionId")]
         [InlineData(null)]
@@ -196,6 +224,14 @@ public void TelemetryCommonPropertiesShouldContainSessionId(string sessionId)
             commonProperties["SessionId"].Should().Be(sessionId);
         }
 
+
+        public static IEnumerable<object[]> LLMTelemetryTestCases => new List<object[]>{
+            new object[] { new Dictionary<string, string> { { "CLAUDECODE", "1" } }, "claude" },
+            new object[] { new Dictionary<string, string> { { "CURSOR_EDITOR", "1" } }, "cursor" },
+            new object[] { new Dictionary<string, string> { { "CLAUDECODE", "1" }, { "CURSOR_EDITOR", "1" } }, "claude, cursor" },
+            new object[] { new Dictionary<string, string>(), null },
+        };
+
         public static IEnumerable<object[]> CITelemetryTestCases => new List<object[]>{
             new object[] { new Dictionary<string, string> { { "TF_BUILD", "true" } }, true },
             new object[] { new Dictionary<string, string> { { "GITHUB_ACTIONS", "true" } }, true },