Runner Support for executing Node24 Actions (#3940)

src/Test/L0/Worker/StepHostNodeVersionL0.cs

@@ -0,0 +1,63 @@
+using GitHub.Runner.Worker;
+using GitHub.Runner.Worker.Handlers;
+using Moq;
+using System;
+using System.Runtime.InteropServices;
+using Xunit;
+
+namespace GitHub.Runner.Common.Tests.Worker
+{
+    public sealed class StepHostNodeVersionL0
+    {
+        private Mock<IExecutionContext> _ec;
+        private DefaultStepHost _defaultStepHost;
+
+        public StepHostNodeVersionL0()
+        {
+            _ec = new Mock<IExecutionContext>();
+            _defaultStepHost = new DefaultStepHost();
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void CheckNodeVersionForArm32_Node24OnArm32Linux()
+        {
+            // Test via NodeUtil directly
+            string preferredVersion = "node24";
+            var (nodeVersion, warningMessage) = Common.Util.NodeUtil.CheckNodeVersionForLinuxArm32(preferredVersion);
+
+            // On ARM32 Linux, we should fall back to node20
+            bool isArm32 = RuntimeInformation.ProcessArchitecture == Architecture.Arm ||
+                          Environment.GetEnvironmentVariable("PROCESSOR_ARCHITECTURE")?.Contains("ARM") == true;
+            bool isLinux = RuntimeInformation.IsOSPlatform(OSPlatform.Linux);
+
+            if (isArm32 && isLinux)
+            {
+                // Should downgrade to node20 on ARM32 Linux
+                Assert.Equal("node20", nodeVersion);
+                Assert.NotNull(warningMessage);
+                Assert.Contains("Node 24 is not supported on Linux ARM32 platforms", warningMessage);
+            }
+            else
+            {
+                // On non-ARM32 platforms, should pass through the version unmodified
+                Assert.Equal("node24", nodeVersion);
+                Assert.Null(warningMessage);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void CheckNodeVersionForArm32_PassThroughNonNode24Versions()
+        {
+            string preferredVersion = "node20";
+            var (nodeVersion, warningMessage) = Common.Util.NodeUtil.CheckNodeVersionForLinuxArm32(preferredVersion);
+
+            // Should never modify the version for non-node24 inputs
+            Assert.Equal("node20", nodeVersion);
+            Assert.Null(warningMessage);
+        }
+    }
+}