chore: import upstream snapshot with attribution

TestProjects/UnityMCPTests/Assets/Tests/PlayMode/MCPForUnityTests.PlayMode.asmdef

@@ -0,0 +1,21 @@
+{
+  "name": "MCPForUnityTests.PlayMode",
+  "rootNamespace": "",
+  "references": [
+    "UnityEngine.TestRunner",
+    "UnityEditor.TestRunner"
+  ],
+  "includePlatforms": [],
+  "excludePlatforms": [],
+  "allowUnsafeCode": false,
+  "overrideReferences": true,
+  "precompiledReferences": [
+    "nunit.framework.dll"
+  ],
+  "autoReferenced": false,
+  "defineConstraints": [
+    "UNITY_INCLUDE_TESTS"
+  ],
+  "versionDefines": [],
+  "noEngineReferences": false
+}

TestProjects/UnityMCPTests/Assets/Tests/PlayMode/MCPForUnityTests.PlayMode.asmdef.meta

@@ -0,0 +1,7 @@
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+guid: ee22713734c3444ea97b26bc4f4009c6
+AssemblyDefinitionImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

TestProjects/UnityMCPTests/Assets/Tests/PlayMode/PlayModeBasicTests.cs

@@ -0,0 +1,86 @@
+using System.Collections;
+using NUnit.Framework;
+using UnityEngine;
+using UnityEngine.TestTools;
+
+namespace MCPForUnityTests.PlayMode
+{
+    /// <summary>
+    /// Basic PlayMode tests to verify the MCP test runner handles PlayMode correctly.
+    /// These tests exercise coroutine-based testing which requires Play mode.
+    /// </summary>
+    public class PlayModeBasicTests
+    {
+        [UnityTest]
+        public IEnumerator GameObjectCreation_InPlayMode_Succeeds()
+        {
+            var go = new GameObject("TestObject");
+            Assert.IsNotNull(go);
+            Assert.AreEqual("TestObject", go.name);
+
+            yield return null; // Wait one frame
+
+            Assert.IsTrue(go != null); // Still exists after frame
+            Object.Destroy(go);
+        }
+
+        [UnityTest]
+        public IEnumerator WaitForSeconds_CompletesAfterDelay()
+        {
+            float startTime = Time.time;
+
+            yield return new WaitForSeconds(0.1f);
+
+            float elapsed = Time.time - startTime;
+            Assert.GreaterOrEqual(elapsed, 0.09f, "Should have waited at least 0.09 seconds");
+        }
+
+        [UnityTest]
+        public IEnumerator MultipleFrames_ProgressCorrectly()
+        {
+            int frameCount = Time.frameCount;
+
+            yield return null;
+            yield return null;
+            yield return null;
+
+            int newFrameCount = Time.frameCount;
+            Assert.Greater(newFrameCount, frameCount, "Frame count should have advanced");
+        }
+
+        [UnityTest]
+        public IEnumerator Component_AddAndRemove_InPlayMode()
+        {
+            var go = new GameObject("ComponentTest");
+
+            yield return null;
+
+            var rb = go.AddComponent<Rigidbody>();
+            Assert.IsNotNull(rb);
+            Assert.IsTrue(go.GetComponent<Rigidbody>() != null);
+
+            yield return null;
+
+            Object.Destroy(rb);
+
+            yield return null;
+
+            Assert.IsTrue(go.GetComponent<Rigidbody>() == null);
+            Object.Destroy(go);
+        }
+
+        [UnityTest]
+        public IEnumerator Coroutine_CanYieldMultipleTimes()
+        {
+            int counter = 0;
+
+            for (int i = 0; i < 5; i++)
+            {
+                counter++;
+                yield return null;
+            }
+
+            Assert.AreEqual(5, counter);
+        }
+    }
+}

TestProjects/UnityMCPTests/Assets/Tests/PlayMode/PlayModeBasicTests.cs.meta

@@ -0,0 +1,11 @@
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+guid: 0fdf985950dd444e4977139e67d778a2
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
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