Refresh explorer re-reads every expanded folder (#332)

AGENTS.md

@@ -125,6 +125,7 @@ What follows is how TuiCode implements it today.
 - `Delete` and `F2` are `Explorer`-scoped (Delete must still delete text in the editor). `Ctrl+D` is bound there too: our iTerm2 profile sends forward-delete as `^D`, which the editor's TextView treats as delete-right. The target is the explorer selection when the explorer has focus, else the active tab's file. Launchers close — focusing the editor — before running their command, so `ActionView`/`MnemonicView` capture whether the explorer had focus when they opened (`RunLaunched`).
 - Cut and paste (#127) is a second way to move: `Ctrl+X` marks `FileExplorerView.PendingCut` (drawn faint in `DrawLine`, before the icon handler so the icon dims too) and `Ctrl+V` moves it through the same `Workbench.Move` as `F2`, targeting the folder `NewEntryTarget` would pick. Both are `Explorer`-scoped, so the editor keeps text cut/paste; `CancelCut` (Esc) is enabled only while a cut is pending, so Esc still focuses the editor otherwise. `Delete`/`Move` clear a cut at or under what they touch. Windows Terminal binds `Ctrl+V` to its own paste, so the `xf`/`pf` mnemonics are the fallback.
 - `FileSystemTreeBuilder` hands out fresh `IFileSystemInfo`s on every read and TG's `Branch.Refresh` matches children by reference, so a plain `RefreshObject` collapses every folder under the refreshed node. `FileExplorerView.RefreshKeepingExpansion` records expanded paths and re-expands them.
+- **Refresh explorer** (`re`, Global, no default key, #332) is `FileExplorerView.Refresh`: `RefreshKeepingExpansion` from the root, so only expanded folders are re-read, then the selection is put back by path. A selection that's gone moves to the neighbour of the first vanished entry on its path, found in the tree's pre-refresh listing since the disk no longer has it.
 
 ## Editor gutter (#23)
 

src/TuiCode.Abstractions/CommandIds.cs

@@ -123,6 +123,7 @@ public static class CommandIds
     public const string CutFile = "explorer.action.cutFile";
     public const string PasteFile = "explorer.action.pasteFile";
     public const string CancelCut = "explorer.action.cancelCut";
+    public const string RefreshExplorer = "explorer.action.refresh";
     public const string ConfirmCancel = "confirm.action.cancel";
 
     public const string MoveLinesUp = "editor.action.moveLinesUp";

src/TuiCode.Abstractions/CommandMnemonics.cs

@@ -61,6 +61,7 @@ private static IReadOnlyDictionary<string, string> Build()
             [CommandIds.CompareToRevision] = "ctr",
             [CommandIds.CompareToOtherFile] = "cto",
             [CommandIds.ReloadFromDisk] = "rd",
+            [CommandIds.RefreshExplorer] = "re",
             [CommandIds.ToggleSidebar] = "ts",
             [CommandIds.WidenSidebar] = "ws",
             [CommandIds.NarrowSidebar] = "ns",

src/TuiCode.Explorer/FileExplorerView.cs

@@ -208,6 +208,42 @@ public IFileSystemInfo Move(IFileSystemInfo item, string relativePath)
             ?? throw new IOException($"Moved to '{shown}' but could not locate it in the tree.");
     }
 
+    /// <summary>
+    /// Re-read every expanded folder from disk, keeping them expanded and the selection on the same path. A selection
+    /// that's gone moves to its neighbour, as after <see cref="Delete"/>.
+    /// </summary>
+    public void Refresh()
+    {
+        if (Root is not { } root) return;
+        var reselect = SelectedObject is { } selected ? SurvivingSelection(root, selected.FullName) : null;
+        RefreshKeepingExpansion(root);
+        if (reselect is null) return;
+        SelectedObject = Find(reselect) ?? root;
+        EnsureVisible(SelectedObject);
+    }
+
+    // The tree still lists what was there before the refresh, so the neighbours of the first vanished entry on the path come from it.
+    private string SurvivingSelection(IDirectoryInfo root, string selected)
+    {
+        var fs = root.FileSystem;
+        bool Exists(IFileSystemInfo entry) => fs.File.Exists(entry.FullName) || fs.Directory.Exists(entry.FullName);
+
+        IFileSystemInfo current = root;
+        foreach (var segment in Segments(root, selected))
+        {
+            var siblings = GetChildren(current).ToList();
+            var index = siblings.FindIndex(c => string.Equals(c.Name, segment, StringComparison.Ordinal));
+            if (index < 0) return current.FullName;
+            if (!Exists(siblings[index]))
+            {
+                var neighbour = siblings.Skip(index + 1).Concat(siblings.Take(index).Reverse()).FirstOrDefault(Exists);
+                return (neighbour ?? current).FullName;
+            }
+            current = siblings[index];
+        }
+        return selected;
+    }
+
     internal IReadOnlyCollection<string> MarkedOnDisk => _changedOnDisk;
 
     /// <summary>

src/TuiCode.Workbench/WorkbenchHost.cs

@@ -458,6 +458,8 @@ private void RegisterDefaultCommands()
         _commands.Register(CommandIds.CutFile, "Cut file or folder", CutEntry, CommandScope.Explorer);
         _commands.Register(CommandIds.PasteFile, "Paste file or folder", PasteEntry, CommandScope.Explorer);
         _commands.Register(CommandIds.CancelCut, "Cancel cut", explorer.ClearCut, CommandScope.Explorer, () => explorer.PendingCut is not null);
+        // No default key (#332).
+        _commands.Register(CommandIds.RefreshExplorer, "Refresh explorer", RefreshExplorer, CommandScope.Global, () => explorer.Root is not null);
         explorer.CutCleared += (_, item) => _workbench.StatusBar.ClearMessage(CutMessage(item));
         var search = _workbench.Sidebar.Search;
         // Find covers the whole pane, results list included; these keys belong to the query/replace inputs only.
@@ -1209,6 +1211,12 @@ private void OpenRename()
         ShowPathPrompt(view);
     }
 
+    private void RefreshExplorer()
+    {
+        _workbench.Sidebar.Explorer.Refresh();
+        if (ExplorerIsContext) FocusSidebar();
+    }
+
     private void CutEntry()
     {
         var fromExplorer = ExplorerIsContext;

tests/TuiCode.Tests/ExplorerRefreshHostTests.cs

@@ -0,0 +1,119 @@
+using TuiCode.Abstractions;
+using TuiCode.Explorer;
+using TuiCode.Workbench;
+using TuiCode.Workbench.Actions;
+using TuiCode.Workbench.Parts;
+using TuiCode.Workbench.Services;
+
+namespace TuiCode.Tests;
+
+// Refresh explorer from the palette, the leader and a user's own key (#332). Boots a TG Application — serialised (#77).
+public class ExplorerRefreshHostTests : StaticConfigurationTest
+{
+    private readonly MockFileSystem _fs = new();
+    private readonly CommandService _commands = new();
+    private readonly KeybindingService _keybindings;
+
+    public ExplorerRefreshHostTests() => _keybindings = new KeybindingService(_commands);
+
+    [Fact]
+    public void Is_a_global_command_with_a_label_mnemonic_and_no_default_key()
+    {
+        using var workbench = BuildWorkbench();
+        using var _ = BuildHost(workbench);
+
+        var command = Assert.Single(_commands.Registered, c => c.Id == CommandIds.RefreshExplorer);
+        Assert.Equal("Refresh explorer", command.Label);
+        Assert.Equal(CommandScope.Global, command.Scope);
+        Assert.Equal("re", CommandMnemonics.For(CommandIds.RefreshExplorer));
+        Assert.DoesNotContain(_keybindings.Bindings, b => b.CommandId == CommandIds.RefreshExplorer);
+    }
+
+    [Fact]
+    public async Task The_palette_refreshes_the_explorer()
+    {
+        using var workbench = BuildWorkbench();
+        using var host = BuildHost(workbench);
+
+        await HostSteps.Run(host,
+            ChangeOnDisk,
+            () => host.App.InjectKey(Key.E.WithCtrl),
+            () => Palette(workbench) is not null,
+            () => { foreach (var c in "refresh explorer") host.App.InjectKey(new Key(c)); },
+            () => Palette(workbench)!.Labels.SequenceEqual(["Refresh explorer"]),
+            () => host.App.InjectKey(Key.Enter),
+            () => Palette(workbench) is null);
+
+        Assert.Equal(["b.txt"], Names(workbench));
+    }
+
+    [Fact]
+    public async Task The_leader_then_re_refreshes_the_explorer()
+    {
+        using var workbench = BuildWorkbench();
+        using var host = BuildHost(workbench);
+
+        await HostSteps.Run(host,
+            ChangeOnDisk,
+            () => host.App.InjectKey(Key.Space.WithCtrl),
+            () => host.App.InjectKey(Key.R),
+            () => host.App.InjectKey(Key.E),
+            () => Names(workbench).SequenceEqual(["b.txt"]));
+    }
+
+    [Fact]
+    public async Task A_key_bound_in_settings_refreshes_the_explorer()
+    {
+        using var workbench = BuildWorkbench();
+        var settings = new InMemorySettingsService();
+        settings.SetKeybindingOverrides([new KeybindingOverride(TestKeys.Chord("F5"), CommandIds.RefreshExplorer)]);
+        using var host = BuildHost(workbench, settings);
+
+        await HostSteps.Run(host,
+            ChangeOnDisk,
+            () => host.App.InjectKey(Key.F5),
+            () => Names(workbench).SequenceEqual(["b.txt"]));
+    }
+
+    [Fact]
+    public async Task Refreshing_from_the_explorers_leader_leaves_the_keys_in_the_explorer()
+    {
+        using var workbench = BuildWorkbench();
+        using var host = BuildHost(workbench);
+
+        await HostSteps.Run(host,
+            () => _commands.TryExecute(CommandIds.FocusSidebar),
+            () => workbench.StatusBar.DisplayedFocus == "Explorer",
+            ChangeOnDisk,
+            () => host.App.InjectKey(Key.Space.WithCtrl),
+            () => host.App.InjectKey(Key.R),
+            () => host.App.InjectKey(Key.E),
+            () => Names(workbench).SequenceEqual(["b.txt"]));
+
+        Assert.Equal("Explorer", workbench.StatusBar.DisplayedFocus);
+    }
+
+    private void ChangeOnDisk()
+    {
+        _fs.File.Delete("/work/a.txt");
+        _fs.AddFile("/work/b.txt", new MockFileData("b"));
+    }
+
+    private static string[] Names(Workbench.Workbench workbench) =>
+        workbench.Sidebar.Explorer.GetChildren(workbench.Sidebar.Explorer.Root!).Select(c => c.Name).ToArray();
+
+    private static ActionView? Palette(Workbench.Workbench workbench) =>
+        workbench.SubViews.OfType<ActionView>().SingleOrDefault();
+
+    private Workbench.Workbench BuildWorkbench()
+    {
+        var workbench = new Workbench.Workbench(new SidebarPart(new FileExplorerView()), new EditorPart(), new StatusBarPart());
+        _fs.AddFile("/work/a.txt", new MockFileData("a"));
+        workbench.Sidebar.Explorer.Open(_fs.DirectoryInfo.New("/work"));
+        return workbench;
+    }
+
+    private WorkbenchHost BuildHost(Workbench.Workbench workbench, ISettingsService? settings = null) =>
+        new(workbench, _commands, _keybindings, new InputScopeStack(), settings ?? new InMemorySettingsService(),
+            driverName: DriverRegistry.Names.ANSI);
+}