Fixes

src/Apps/NetPad.Apps.App/App/src/core/@plugins/omnisharp/utils/text-change-util.ts

@@ -84,8 +84,10 @@ export class TextChangeUtil {
     }
 
     private static getNamespacesFromUsings(textChange: LinePositionSpanTextChange): string[] {
-        return textChange.newText?.split("\n")
-            .filter(l => !!l && l.trim())
+        return textChange.newText
+            ?.split("\n")
+            .map(l => l?.trim()) // to remove empty parts
+            .filter(l => !!l)
             .map(l => Util.trimWord(l, "using "))
             .map(l => Util.trimEnd(l, ";"))
             .map(l => l.trim())

src/Apps/NetPad.Apps.App/Startup.cs

@@ -78,7 +78,7 @@ public void ConfigureServices(IServiceCollection services)
         services.AddTransient<IAssemblyLoader, UnloadableAssemblyLoader>();
         services.AddTransient<ILogoService, LogoService>();
         services.AddSingleton<IAppStatusMessagePublisher, AppStatusMessagePublisher>();
-        services.AddSingleton<IKeyValueDataStore, FileSystemKeyValueDataStore>();
+        services.AddSingleton<ITrivialDataStore, FileSystemTrivialDataStore>();
 
         // Scripts
         services.AddTransient<IScriptRepository, FileSystemScriptRepository>();

src/Core/NetPad.Application/Sessions/Session.cs

@@ -1,4 +1,5 @@
 using Microsoft.Extensions.Logging;
+using NetPad.Data;
 using NetPad.Events;
 using NetPad.Exceptions;
 using NetPad.Scripts;
@@ -7,18 +8,23 @@ namespace NetPad.Sessions;
 
 public class Session : ISession
 {
+    private const string CurrentActiveSaveKey = "session.active";
+
     private readonly IScriptEnvironmentFactory _scriptEnvironmentFactory;
+    private readonly ITrivialDataStore _trivialDataStore;
     private readonly IEventBus _eventBus;
     private readonly ILogger<Session> _logger;
     private readonly List<ScriptEnvironment> _environments;
     private Guid? _lastActiveScriptId;
 
     public Session(
         IScriptEnvironmentFactory scriptEnvironmentFactory,
+        ITrivialDataStore trivialDataStore,
         IEventBus eventBus,
         ILogger<Session> logger)
     {
         _scriptEnvironmentFactory = scriptEnvironmentFactory;
+        _trivialDataStore = trivialDataStore;
         _eventBus = eventBus;
         _logger = logger;
         _environments = new List<ScriptEnvironment>();
@@ -53,17 +59,21 @@ public async Task OpenAsync(Script script, bool activate = true)
 
     public async Task OpenAsync(IEnumerable<Script> scripts)
     {
-        Script? last = null;
+        scripts = scripts.ToArray();
 
         foreach (var script in scripts)
         {
             await OpenAsync(script, activate: false);
-            last = script;
         }
 
-        if (last != null)
+        if (Guid.TryParse(_trivialDataStore.Get<string>(CurrentActiveSaveKey), out var lastSavedScriptId) &&
+            scripts.Any(s => s.Id == lastSavedScriptId))
+        {
+            await ActivateAsync(lastSavedScriptId);
+        }
+        else
         {
-            await ActivateAsync(last.Id);
+            await ActivateAsync(scripts.LastOrDefault()?.Id);
         }
     }
 
@@ -126,7 +136,9 @@ public Task ActivateAsync(Guid? scriptId)
         }
 
         if (scriptId == null)
+        {
             newActive = null;
+        }
         else
         {
             var environment = Get(scriptId.Value);
@@ -136,6 +148,8 @@ public Task ActivateAsync(Guid? scriptId)
         Active = newActive;
         _eventBus.PublishAsync(new ActiveEnvironmentChangedEvent(newActive?.Script.Id));
 
+        _trivialDataStore.Set(CurrentActiveSaveKey, Active?.Script.Id);
+
         return Task.CompletedTask;
     }
 
@@ -147,5 +161,6 @@ public Task ActivateLastActiveScriptAsync()
         return Task.CompletedTask;
     }
 
-    private bool CanActivateLastActiveScript() => _lastActiveScriptId != null && _environments.Any(e => e.Script.Id == _lastActiveScriptId);
+    private bool CanActivateLastActiveScript() =>
+        _lastActiveScriptId != null && _environments.Any(e => e.Script.Id == _lastActiveScriptId);
 }

src/Core/NetPad.Domain/Data/ITrivialDataStore.cs

@@ -0,0 +1,12 @@
+namespace NetPad.Data;
+
+/// <summary>
+/// Represents a key-value data store that stores trivial data. Trivial data is data
+/// that is not essential to the functionality of the application or the user experience.
+/// </summary>
+public interface ITrivialDataStore
+{
+    TValue? Get<TValue>(string key) where TValue : class;
+    void Set<TValue>(string key, TValue value);
+    bool Contains(string key);
+}

src/Infrastructure/NetPad.Electron/UiInterop/ElectronWindowService.cs

@@ -11,14 +11,14 @@ namespace NetPad.Electron.UiInterop;
 public class ElectronWindowService : IUiWindowService
 {
     private readonly WindowManager _windowManager;
-    private readonly IKeyValueDataStore _keyValueDataStore;
+    private readonly ITrivialDataStore _trivialDataStore;
     private readonly Settings _settings;
     private readonly ILogger<ElectronWindowService> _logger;
 
-    public ElectronWindowService(WindowManager windowManager, IKeyValueDataStore keyValueDataStore, Settings settings, ILogger<ElectronWindowService> logger)
+    public ElectronWindowService(WindowManager windowManager, ITrivialDataStore trivialDataStore, Settings settings, ILogger<ElectronWindowService> logger)
     {
         _windowManager = windowManager;
-        _keyValueDataStore = keyValueDataStore;
+        _trivialDataStore = trivialDataStore;
         _settings = settings;
         _logger = logger;
     }
@@ -44,7 +44,7 @@ private async Task RestoreMainWindowPositionAsync(BrowserWindow window)
     {
         try
         {
-            var savedBounds = _keyValueDataStore.Get<Rectangle>("main-window.bounds");
+            var savedBounds = _trivialDataStore.Get<Rectangle>("main-window.bounds");
             if (savedBounds != null)
             {
                 window.SetBounds(savedBounds);
@@ -67,7 +67,7 @@ private async Task RestoreMainWindowPositionAsync(BrowserWindow window)
 
         window.OnClose += async () =>
         {
-            _keyValueDataStore.Set("main-window.bounds", await window.GetBoundsAsync());
+            _trivialDataStore.Set("main-window.bounds", await window.GetBoundsAsync());
         };
     }
 

src/Infrastructure/NetPad.Infrastructure/FileSystemKeyValueDataStore.cs → src/Infrastructure/NetPad.Infrastructure/FileSystemTrivialDataStore.cs

@@ -8,7 +8,7 @@
 
 namespace NetPad;
 
-public class FileSystemKeyValueDataStore : IKeyValueDataStore
+public class FileSystemTrivialDataStore : ITrivialDataStore
 {
     private static readonly FilePath _storeFilePath = AppDataProvider.AppDataDirectoryPath.CombineFilePath("key-values.txt");
     private static readonly object _fileLock = new();

src/Plugins/NetPad.Plugins.OmniSharp/Services/AppOmniSharpServer.cs

@@ -277,10 +277,7 @@ private void InitializeEventHandlers()
         Subscribe<ScriptNamespacesUpdatedEvent>(async ev =>
         {
             if (ev.Script.Id != _environment.Script.Id) return;
-
-            var script = _environment.Script;
-            var parsingResult = _codeParser.Parse(script.Code, script.Config.Kind, script.Config.Namespaces);
-            await UpdateOmniSharpCodeBufferWithBootstrapperProgramAsync(parsingResult);
+            await UpdateOmniSharpCodeBufferAsync();
         });
 
         Subscribe<ScriptReferencesUpdatedEvent>(async ev =>
@@ -385,8 +382,6 @@ private async Task UpdateOmniSharpCodeBufferWithDataConnectionAsync(DataConnecti
         // Needed to trigger diagnostics and semantic highlighting for script file
         await Task.Delay(1000);
         await UpdateOmniSharpCodeBufferAsync();
-
-        await _eventBus.PublishAsync(new OmniSharpAsyncBufferUpdateCompletedEvent(_environment.Script.Id));
     }
 
     private async Task UpdateOmniSharpCodeBufferWithDataConnectionProgramAsync(Task<DataConnectionSourceCode>? sourceCodeTask)
@@ -438,5 +433,7 @@ await OmniSharpServer.SendAsync(new UpdateBufferRequest
         {
             semaphore.Release();
         }
+
+        await _eventBus.PublishAsync(new OmniSharpAsyncBufferUpdateCompletedEvent(_environment.Script.Id));
     }
 }

src/Tests/NetPad.Tests/Helpers/SessionTestHelper.cs

@@ -4,6 +4,7 @@
 using NetPad.Events;
 using NetPad.Scripts;
 using NetPad.Sessions;
+using NetPad.Tests.Services;
 
 namespace NetPad.Tests.Helpers;
 
@@ -13,6 +14,7 @@ public static Session CreateSession(IServiceProvider serviceProvider)
     {
         return new Session(
             new DefaultScriptEnvironmentFactory(serviceProvider),
+            new NullTrivialDataStore(),
             serviceProvider.GetRequiredService<IEventBus>(),
             serviceProvider.GetRequiredService<ILogger<Session>>());
     }

src/Tests/NetPad.Tests/Services/NullTrivialDataStore.cs

@@ -0,0 +1,20 @@
+using NetPad.Data;
+
+namespace NetPad.Tests.Services;
+
+public class NullTrivialDataStore : ITrivialDataStore
+{
+    public TValue? Get<TValue>(string key) where TValue : class
+    {
+        return null;
+    }
+
+    public void Set<TValue>(string key, TValue value)
+    {
+    }
+
+    public bool Contains(string key)
+    {
+        return false;
+    }
+}