feat(startup): 支持等待 ContextLoader 启动

Tests/ShrinkAppLoaderHostTests.cs

@@ -2,6 +2,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Reflection;
 using Cysharp.Threading.Tasks;
 using NUnit.Framework;
 using ShrinkApp;
@@ -39,6 +40,8 @@ namespace ShrinkContext.AppAdapter.Tests
         [TearDown]
         public void TearDown()
         {
+            ResetBootstrapperState();
+            SetSharedSettings(null);
             if (_settings != null)
                 Object.DestroyImmediate(_settings);
         }
@@ -68,6 +71,33 @@ namespace ShrinkContext.AppAdapter.Tests
             CollectionAssert.AreEquivalent(new[] { "app.a", "app.b" }, probe.Value!.ModuleIds);
         }
 
+        [Test]
+        public void WaitUntilStartedAsync_AllConcurrentWaitersCompleteTogether()
+        {
+            PrepareBootstrapperWaitState();
+
+            var first = ShrinkAppLoaderBootstrapper.WaitUntilStartedAsync();
+            var second = ShrinkAppLoaderBootstrapper.WaitUntilStartedAsync();
+            CompleteBootstrapperStartup(null);
+
+            TestAwait.Run(UniTask.WhenAll(first, second));
+            Assert.IsNull(ShrinkAppLoaderBootstrapper.StartError);
+        }
+
+        [Test]
+        public void WaitUntilStartedAsync_PropagatesObservableStartupError()
+        {
+            PrepareBootstrapperWaitState();
+            var expected = new InvalidOperationException("test startup failure");
+            CompleteBootstrapperStartup(expected);
+
+            var actual = Assert.Throws<InvalidOperationException>(() =>
+                TestAwait.Run(ShrinkAppLoaderBootstrapper.WaitUntilStartedAsync()));
+
+            Assert.AreSame(expected, actual);
+            Assert.AreSame(expected, ShrinkAppLoaderBootstrapper.StartError);
+        }
+
         [Test]
         public void SetModuleDisabled_RetiresModuleAndDependents_EnableReloadsWithoutRestart()
         {
@@ -210,5 +240,36 @@ namespace ShrinkContext.AppAdapter.Tests
 
             public string Value { get; }
         }
+
+        private void PrepareBootstrapperWaitState()
+        {
+            ResetBootstrapperState();
+            _settings.hostingMode = ShrinkAppHostingMode.ContextLoader;
+            SetSharedSettings(_settings);
+        }
+
+        private static void CompleteBootstrapperStartup(Exception? error)
+        {
+            var method = typeof(ShrinkAppLoaderBootstrapper).GetMethod(
+                "CompleteStartup", BindingFlags.NonPublic | BindingFlags.Static);
+            Assert.IsNotNull(method);
+            method!.Invoke(null, new object?[] { error });
+        }
+
+        private static void ResetBootstrapperState()
+        {
+            var method = typeof(ShrinkAppLoaderBootstrapper).GetMethod(
+                "ResetStaticState", BindingFlags.NonPublic | BindingFlags.Static);
+            Assert.IsNotNull(method);
+            method!.Invoke(null, null);
+        }
+
+        private static void SetSharedSettings(ShrinkAppSettings? settings)
+        {
+            var property = typeof(ShrinkAppSettings).GetProperty(
+                nameof(ShrinkAppSettings.Instance), BindingFlags.Public | BindingFlags.Static);
+            Assert.IsNotNull(property);
+            property!.SetValue(null, settings);
+        }
     }
 }