✨ Reload projects when analyzer dlls change

src/SharpIDE.Application/Features/FileWatching/AnalyzerFileWatcher.cs

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+using System.Collections.Concurrent;
+using System.Collections.Immutable;
+using FileWatcherEx;
+using Microsoft.CodeAnalysis.Shared.TestHooks;
+using Microsoft.CodeAnalysis.Threading;
+using SharpIDE.Application.Features.Events;
+
+namespace SharpIDE.Application.Features.FileWatching;
+
+public class AnalyzerFileWatcher
+{
+	private readonly AsyncBatchingWorkQueue<string> _fileChangedQueue;
+
+	public AnalyzerFileWatcher()
+	{
+		_fileChangedQueue = new AsyncBatchingWorkQueue<string>(
+			TimeSpan.FromMilliseconds(500),
+			async (filePaths, ct) => await GlobalEvents.Instance.AnalyzerDllsChanged.InvokeParallelAsync(filePaths.ToImmutableArray()),
+			new AsynchronousOperationListenerProvider.NullOperationListener(),
+			CancellationToken.None);
+	}
+
+	private readonly ConcurrentDictionary<string, FileSystemWatcherEx> _fileWatchers = new();
+
+	// I wanted to avoid this, but unfortunately we have to watch individual files in different directories
+	public async Task StartWatchingFiles(ImmutableArray<string> filePaths)
+	{
+		// This can definitely be optimized to not recreate watchers unnecessarily
+		var existingFileWatchers = _fileWatchers.Values.ToList();
+		foreach (var watcher in existingFileWatchers)
+		{
+			watcher.OnChanged -= OnFileChanged;
+			watcher.Dispose();
+		}
+		_fileWatchers.Clear();
+
+		foreach (var filePath in filePaths)
+		{
+			var fileWatcher = new FileSystemWatcherEx(Path.GetDirectoryName(filePath)!)
+			{
+				Filter = Path.GetFileName(filePath),
+				NotifyFilter = NotifyFilters.LastWrite | NotifyFilters.Size
+			};
+
+			fileWatcher.OnChanged += OnFileChanged;
+			fileWatcher.Start();
+			_fileWatchers.TryAdd(filePath, fileWatcher);
+		}
+	}
+
+	private void OnFileChanged(object? sender, FileChangedEvent e)
+	{
+		_fileChangedQueue.AddWork(e.FullPath);
+	}
+}