Fix KeyNotFoundException when simulator lacks runtimeIdentifier or version

src/Microsoft.DotNet.XHarness.CLI/Commands/Apple/Simulators/SimulatorsCommand.cs

@@ -238,7 +238,13 @@ protected async Task<IEnumerable<Simulator>> GetAvailableSimulators()
 
             foreach (JsonProperty sim in simulators.RootElement.EnumerateObject())
             {
-                if (sim.Value.GetProperty("runtimeIdentifier").GetString() == runtimeIdentifier)
+                // Skip entries that don't have a runtimeIdentifier property (e.g., unusable simulators)
+                if (!sim.Value.TryGetProperty("runtimeIdentifier", out var runtimeIdProperty))
+                {
+                    continue;
+                }
+
+                if (runtimeIdProperty.GetString() == runtimeIdentifier)
                 {
                     var version = sim.Value.GetProperty("version").GetString();
                     if (version == null)

tests/Microsoft.DotNet.XHarness.CLI.Tests/Commands/Apple/SimulatorsCommandTests.cs

@@ -0,0 +1,156 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Text.Json;
+using Xunit;
+
+namespace Microsoft.DotNet.XHarness.CLI.Tests.Commands.Apple;
+
+public class SimulatorsCommandTests
+{
+    [Fact]
+    public void JsonWithoutRuntimeIdentifier_ShouldBeSkipped()
+    {
+        // This test validates the fix for the issue where simulators without runtimeIdentifier
+        // (like unusable simulators) should be skipped rather than causing an exception.
+
+        // Sample JSON similar to what's returned by xcrun simctl runtime list -j
+        // This includes an entry without runtimeIdentifier (the unusable simulator)
+        var json = @"{
+            ""1F039DDE-73B1-4BF2-9FE0-7B089D0ABE5E"": {
+                ""build"": ""23J352"",
+                ""runtimeIdentifier"": ""com.apple.CoreSimulator.SimRuntime.tvOS-26-0"",
+                ""version"": ""26.0"",
+                ""state"": ""Ready""
+            },
+            ""8728D520-0F86-4227-AE03-716249BBB18C"": {
+                ""identifier"": ""8728D520-0F86-4227-AE03-716249BBB18C"",
+                ""kind"": ""Cryptex Disk Image"",
+                ""state"": ""Unusable"",
+                ""signatureState"": ""Other Signature Error""
+            },
+            ""2A448011-F93C-427C-A6F2-CF5EFA39290F"": {
+                ""build"": ""23A343"",
+                ""runtimeIdentifier"": ""com.apple.CoreSimulator.SimRuntime.iOS-26-0"",
+                ""version"": ""26.0"",
+                ""state"": ""Ready""
+            }
+        }";
+
+        var simulators = JsonDocument.Parse(json);
+
+        // Simulate the logic from IsInstalled method
+        var runtimeIdentifierToFind = "com.apple.CoreSimulator.SimRuntime.iOS-26-0";
+        string? foundVersion = null;
+        bool exceptionThrown = false;
+
+        try
+        {
+            foreach (JsonProperty sim in simulators.RootElement.EnumerateObject())
+            {
+                // This is the fix: check if property exists before accessing it
+                if (!sim.Value.TryGetProperty("runtimeIdentifier", out var runtimeIdProperty))
+                {
+                    // Skip entries without runtimeIdentifier
+                    continue;
+                }
+
+                if (runtimeIdProperty.GetString() == runtimeIdentifierToFind)
+                {
+                    foundVersion = sim.Value.GetProperty("version").GetString();
+                    break;
+                }
+            }
+        }
+        catch (System.Collections.Generic.KeyNotFoundException)
+        {
+            exceptionThrown = true;
+        }
+
+        // Verify that:
+        // 1. No exception was thrown
+        Assert.False(exceptionThrown, "KeyNotFoundException should not be thrown when entry lacks runtimeIdentifier");
+
+        // 2. We found the correct simulator
+        Assert.Equal("26.0", foundVersion);
+    }
+
+    [Fact]
+    public void JsonWithRuntimeIdentifier_ShouldBeProcessed()
+    {
+        // This test ensures that simulators with runtimeIdentifier are still processed correctly
+
+        var json = @"{
+            ""2A448011-F93C-427C-A6F2-CF5EFA39290F"": {
+                ""build"": ""23A343"",
+                ""runtimeIdentifier"": ""com.apple.CoreSimulator.SimRuntime.iOS-26-0"",
+                ""version"": ""26.0"",
+                ""state"": ""Ready""
+            }
+        }";
+
+        var simulators = JsonDocument.Parse(json);
+        var runtimeIdentifierToFind = "com.apple.CoreSimulator.SimRuntime.iOS-26-0";
+        string? foundVersion = null;
+
+        foreach (JsonProperty sim in simulators.RootElement.EnumerateObject())
+        {
+            if (!sim.Value.TryGetProperty("runtimeIdentifier", out var runtimeIdProperty))
+            {
+                continue;
+            }
+
+            if (runtimeIdProperty.GetString() == runtimeIdentifierToFind)
+            {
+                foundVersion = sim.Value.GetProperty("version").GetString();
+                break;
+            }
+        }
+
+        Assert.Equal("26.0", foundVersion);
+    }
+
+    [Fact]
+    public void JsonWithOnlyUnusableSimulators_ShouldNotFindMatch()
+    {
+        // Test scenario where all entries lack runtimeIdentifier
+
+        var json = @"{
+            ""8728D520-0F86-4227-AE03-716249BBB18C"": {
+                ""identifier"": ""8728D520-0F86-4227-AE03-716249BBB18C"",
+                ""kind"": ""Cryptex Disk Image"",
+                ""state"": ""Unusable""
+            }
+        }";
+
+        var simulators = JsonDocument.Parse(json);
+        var runtimeIdentifierToFind = "com.apple.CoreSimulator.SimRuntime.iOS-26-0";
+        string? foundVersion = null;
+        bool exceptionThrown = false;
+
+        try
+        {
+            foreach (JsonProperty sim in simulators.RootElement.EnumerateObject())
+            {
+                if (!sim.Value.TryGetProperty("runtimeIdentifier", out var runtimeIdProperty))
+                {
+                    continue;
+                }
+
+                if (runtimeIdProperty.GetString() == runtimeIdentifierToFind)
+                {
+                    foundVersion = sim.Value.GetProperty("version").GetString();
+                    break;
+                }
+            }
+        }
+        catch (System.Collections.Generic.KeyNotFoundException)
+        {
+            exceptionThrown = true;
+        }
+
+        Assert.False(exceptionThrown, "KeyNotFoundException should not be thrown");
+        Assert.Null(foundVersion);
+    }
+}