Fixed an incomplete plugin start with extensive enterprise configurations (#1033)

app/Tests/Tools/PluginSystem/PluginTimeoutTests.cs

@@ -0,0 +1,38 @@
+using AIStudio.Tools.PluginSystem;
+
+namespace AIStudio.Tests.Tools.PluginSystem;
+
+/// <summary>
+/// Checks that a plugin whose code never finishes can be stopped.
+/// </summary>
+/// <remarks>
+/// Every plugin gets a time limit of its own while it is loaded and started, so that one plugin
+/// cannot keep all the others from starting. That limit is only worth something when the Lua
+/// runtime gives up on a cancelled token, even in the middle of a loop which never yields. If it
+/// did not, a single plugin like that would hang the start of AI Studio for good.
+/// </remarks>
+[TestFixture]
+public sealed class PluginTimeoutTests
+{
+    private const string ENDLESS_PLUGIN = """
+                                          ID = "0b7e5c3a-4f1d-4e8b-9a6c-2d3f4e5a6b7c"
+                                          while true do end
+                                          """;
+
+    [Test]
+    public async Task ALoopWhichNeverEndsIsStopped()
+    {
+        //
+        // The loop runs on its own, and when the runtime ignores the token, it outlives this test.
+        // It therefore gets the token alone, never the source, which is disposed at the end:
+        //
+        using var timeout = new CancellationTokenSource(TimeSpan.FromMilliseconds(200));
+        var token = timeout.Token;
+        var loading = Task.Run(() => PluginFactory.Load(null, ENDLESS_PLUGIN, cancellationToken: token));
+
+        var finishedInTime = await Task.WhenAny(loading, Task.Delay(TimeSpan.FromSeconds(10))) == loading;
+
+        Assert.That(finishedInTime, Is.True, "The Lua runtime ignored the cancelled token.");
+        Assert.That(async () => await loading, Throws.InstanceOf<OperationCanceledException>(), "Only a cancellation tells a time limit apart from a broken plugin.");
+    }
+}