Add Wave18_0 changewave and put AddSdkResolvedEnvironmentVariable beh…

…ind it Co-authored-by: rainersigwald <3347530+rainersigwald@users.noreply.github.com>
dotnet · Copilot · Jul 16, 2025 · Jul 16, 2025 · Jul 16, 2025 · Jul 17, 2025
commit 21a5917b816972d2eb3f51b7c435d459ce0d6779
diff --git a/src/Build.UnitTests/ChangeWaves_Tests.cs b/src/Build.UnitTests/ChangeWaves_Tests.cs
@@ -231,5 +231,43 @@ public void CorrectlyDetermineDisabledFeatures()
                 }
             }
         }
+
+        [Fact]
+        public void Wave18_0IsIncludedInAllWaves()
+        {
+            using (TestEnvironment env = TestEnvironment.Create())
+            {
+                ChangeWaves.AllWaves.ShouldContain(ChangeWaves.Wave18_0);
+                ChangeWaves.Wave18_0.ShouldBe(new Version(18, 0));
+            }
+        }
+
+        [Fact]
+        public void Wave18_0FeaturesAreEnabledByDefault()
+        {
+            using (TestEnvironment env = TestEnvironment.Create())
+            {
+                SetChangeWave(string.Empty, env);
+
+                buildSimpleProjectAndValidateChangeWave(testEnvironment: env,
+                                                        versionToCheckAgainstCurrentChangeWave: ChangeWaves.Wave18_0,
+                                                        currentChangeWaveShouldUltimatelyResolveTo: ChangeWaves.EnableAllFeatures,
+                                                        warningCodesLogShouldContain: null);
+            }
+        }
+
+        [Fact]
+        public void Wave18_0FeaturesCanBeDisabled()
+        {
+            using (TestEnvironment env = TestEnvironment.Create())
+            {
+                SetChangeWave(ChangeWaves.Wave18_0.ToString(), env);
+
+                buildSimpleProjectAndValidateChangeWave(testEnvironment: env,
+                                                        versionToCheckAgainstCurrentChangeWave: ChangeWaves.Wave18_0,
+                                                        currentChangeWaveShouldUltimatelyResolveTo: ChangeWaves.Wave18_0,
+                                                        warningCodesLogShouldContain: null);
+            }
+        }
     }
 }
diff --git a/src/Build/Evaluation/Evaluator.cs b/src/Build/Evaluation/Evaluator.cs
@@ -1881,9 +1881,12 @@ static string EvaluateProperty(string value, IElementLocation location,
 
                 if (sdkResult?.EnvironmentVariablesToAdd is IDictionary<string, string> sdkEnvironmentVariablesToAdd && sdkEnvironmentVariablesToAdd.Count > 0)
                 {
-                    foreach (var environmentVariable in sdkEnvironmentVariablesToAdd)
+                    if (ChangeWaves.AreFeaturesEnabled(ChangeWaves.Wave18_0))
                     {
-                        _data.AddSdkResolvedEnvironmentVariable(environmentVariable.Key, environmentVariable.Value);
+                        foreach (var environmentVariable in sdkEnvironmentVariablesToAdd)
+                        {
+                            _data.AddSdkResolvedEnvironmentVariable(environmentVariable.Key, environmentVariable.Value);
+                        }
                     }
                 }
 
@@ -1898,8 +1901,10 @@ static string EvaluateProperty(string value, IElementLocation location,
                         "dotnet.exe");
                     if (File.Exists(dotnetExe))
                     {
-
-                        _data.AddSdkResolvedEnvironmentVariable("DOTNET_HOST_PATH", dotnetExe);
+                        if (ChangeWaves.AreFeaturesEnabled(ChangeWaves.Wave18_0))
+                        {
+                            _data.AddSdkResolvedEnvironmentVariable("DOTNET_HOST_PATH", dotnetExe);
+                        }
                     }
                 }
 

diff --git a/src/Framework/ChangeWaves.cs b/src/Framework/ChangeWaves.cs
@@ -30,7 +30,8 @@ internal static class ChangeWaves
         internal static readonly Version Wave17_10 = new Version(17, 10);
         internal static readonly Version Wave17_12 = new Version(17, 12);
         internal static readonly Version Wave17_14 = new Version(17, 14);
-        internal static readonly Version[] AllWaves = { Wave17_10, Wave17_12, Wave17_14 };
+        internal static readonly Version Wave18_0 = new Version(18, 0);
+        internal static readonly Version[] AllWaves = { Wave17_10, Wave17_12, Wave17_14, Wave18_0 };
 
         /// <summary>
         /// Special value indicating that all features behind all Change Waves should be enabled.