feat: add per-file discard changes in Changes view

Right-click a file in the Changes view to discard its uncommitted changes.
Shows a confirmation dialog before executing. Handles modified (git checkout),
untracked (delete), and deleted (git restore) files. Includes path traversal
safety checks in the Rust backend.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src-tauri/src/commands/git.rs

@@ -128,6 +128,13 @@ pub async fn git_remote_status(vault_path: String) -> Result<GitRemoteStatus, St
         .map_err(|e| format!("Task panicked: {e}"))?
 }
 
+#[cfg(desktop)]
+#[tauri::command]
+pub fn git_discard_file(vault_path: String, relative_path: String) -> Result<(), String> {
+    let vault_path = expand_tilde(&vault_path);
+    crate::git::discard_file_changes(&vault_path, &relative_path)
+}
+
 #[cfg(desktop)]
 #[tauri::command]
 pub fn is_git_repo(vault_path: String) -> bool {
@@ -247,6 +254,12 @@ pub async fn git_remote_status(_vault_path: String) -> Result<GitRemoteStatus, S
     })
 }
 
+#[cfg(mobile)]
+#[tauri::command]
+pub fn git_discard_file(_vault_path: String, _relative_path: String) -> Result<(), String> {
+    Err("Git discard is not available on mobile".into())
+}
+
 #[cfg(mobile)]
 #[tauri::command]
 pub fn is_git_repo(_vault_path: String) -> bool {

src-tauri/src/git/mod.rs

@@ -21,7 +21,7 @@ pub use remote::{
     git_pull, git_push, git_remote_status, has_remote, GitPullResult, GitPushResult,
     GitRemoteStatus,
 };
-pub use status::{get_modified_files, ModifiedFile};
+pub use status::{discard_file_changes, get_modified_files, ModifiedFile};
 
 use serde::Serialize;
 

src-tauri/src/git/status.rs

@@ -63,6 +63,80 @@ pub fn get_modified_files(vault_path: &str) -> Result<Vec<ModifiedFile>, String>
     Ok(files)
 }
 
+/// Discard uncommitted changes to a single file.
+///
+/// - **Modified / Deleted**: `git checkout -- <file>` restores the last committed version.
+/// - **Untracked / Added**: the file is removed from disk.
+///
+/// The `relative_path` must be relative to `vault_path` (the same format
+/// returned by [`get_modified_files`]).
+pub fn discard_file_changes(vault_path: &str, relative_path: &str) -> Result<(), String> {
+    let vault = Path::new(vault_path);
+    let abs = vault.join(relative_path);
+
+    // Safety: ensure the resolved path stays inside the vault.
+    // Safety: reject any relative_path that tries to escape the vault via `..`.
+    for component in std::path::Path::new(relative_path).components() {
+        if matches!(component, std::path::Component::ParentDir) {
+            return Err("File path is outside the vault".into());
+        }
+    }
+    if abs.exists() {
+        let canonical_vault = vault
+            .canonicalize()
+            .map_err(|e| format!("Cannot resolve vault path: {e}"))?;
+        let canonical_file = abs
+            .canonicalize()
+            .map_err(|e| format!("Cannot resolve file path: {e}"))?;
+        if !canonical_file.starts_with(&canonical_vault) {
+            return Err("File path is outside the vault".into());
+        }
+    }
+
+    // Determine the file status from `git status --porcelain`.
+    let output = Command::new("git")
+        .args(["status", "--porcelain", "--", relative_path])
+        .current_dir(vault)
+        .output()
+        .map_err(|e| format!("Failed to run git status: {e}"))?;
+
+    let stdout = String::from_utf8_lossy(&output.stdout);
+    let line = stdout.lines().find(|l| l.len() >= 4);
+
+    let status_code = line
+        .map(|l| l[..2].trim().to_string())
+        .unwrap_or_default();
+
+    match status_code.as_str() {
+        "??" => {
+            // Untracked — remove from disk.
+            std::fs::remove_file(&abs)
+                .map_err(|e| format!("Failed to delete untracked file: {e}"))?;
+        }
+        _ => {
+            // Modified, deleted, added-to-index, renamed, etc. — restore via git.
+            // Unstage first (ignore errors — file might not be staged).
+            let _ = Command::new("git")
+                .args(["reset", "HEAD", "--", relative_path])
+                .current_dir(vault)
+                .output();
+
+            let checkout = Command::new("git")
+                .args(["checkout", "--", relative_path])
+                .current_dir(vault)
+                .output()
+                .map_err(|e| format!("Failed to run git checkout: {e}"))?;
+
+            if !checkout.status.success() {
+                let stderr = String::from_utf8_lossy(&checkout.stderr);
+                return Err(format!("git checkout failed: {}", stderr.trim()));
+            }
+        }
+    }
+
+    Ok(())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -172,4 +246,82 @@ mod tests {
             after
         );
     }
+
+    #[test]
+    fn test_discard_modified_file() {
+        let dir = setup_git_repo();
+        let vault = dir.path();
+        let vp = vault.to_str().unwrap();
+
+        fs::write(vault.join("note.md"), "# Original\n").unwrap();
+        git_commit(vp, "initial").unwrap();
+
+        // Modify the file
+        fs::write(vault.join("note.md"), "# Changed\n").unwrap();
+        assert_eq!(get_modified_files(vp).unwrap().len(), 1);
+
+        // Discard
+        discard_file_changes(vp, "note.md").unwrap();
+
+        let content = fs::read_to_string(vault.join("note.md")).unwrap();
+        assert_eq!(content, "# Original\n");
+        assert!(get_modified_files(vp).unwrap().is_empty());
+    }
+
+    #[test]
+    fn test_discard_untracked_file() {
+        let dir = setup_git_repo();
+        let vault = dir.path();
+        let vp = vault.to_str().unwrap();
+
+        fs::write(vault.join("init.md"), "# Init\n").unwrap();
+        git_commit(vp, "initial").unwrap();
+
+        // Create an untracked file
+        fs::write(vault.join("new.md"), "# New\n").unwrap();
+        assert!(vault.join("new.md").exists());
+
+        discard_file_changes(vp, "new.md").unwrap();
+
+        assert!(!vault.join("new.md").exists());
+        assert!(get_modified_files(vp).unwrap().is_empty());
+    }
+
+    #[test]
+    fn test_discard_deleted_file() {
+        let dir = setup_git_repo();
+        let vault = dir.path();
+        let vp = vault.to_str().unwrap();
+
+        fs::write(vault.join("note.md"), "# Original\n").unwrap();
+        git_commit(vp, "initial").unwrap();
+
+        // Delete the file
+        fs::remove_file(vault.join("note.md")).unwrap();
+        assert!(!vault.join("note.md").exists());
+
+        discard_file_changes(vp, "note.md").unwrap();
+
+        assert!(vault.join("note.md").exists());
+        let content = fs::read_to_string(vault.join("note.md")).unwrap();
+        assert_eq!(content, "# Original\n");
+    }
+
+    #[test]
+    fn test_discard_rejects_path_outside_vault() {
+        let dir = setup_git_repo();
+        let vault = dir.path();
+        let vp = vault.to_str().unwrap();
+
+        // Need an initial commit so git status works
+        fs::write(vault.join("init.md"), "# Init\n").unwrap();
+        git_commit(vp, "initial").unwrap();
+
+        let result = discard_file_changes(vp, "../../../etc/passwd");
+        assert!(result.is_err(), "Should reject path outside vault, got: {:?}", result);
+        assert!(
+            result.unwrap_err().contains("outside the vault"),
+            "Error should mention 'outside the vault'"
+        );
+    }
 }

src-tauri/src/lib.rs

@@ -140,6 +140,7 @@ pub fn run() {
             commands::get_conflict_mode,
             commands::git_resolve_conflict,
             commands::git_commit_conflict_resolution,
+            commands::git_discard_file,
             commands::is_git_repo,
             commands::init_git_repo,
             commands::check_claude_cli,

src/App.tsx

@@ -312,6 +312,20 @@ function App() {
     openNoteInNewWindow(entry.path, resolvedPath, entry.title)
   }, [resolvedPath])
 
+  const handleDiscardFile = useCallback(async (relativePath: string) => {
+    try {
+      if (isTauri()) {
+        await invoke('git_discard_file', { vaultPath: resolvedPath, relativePath })
+      } else {
+        await mockInvoke('git_discard_file', { vaultPath: resolvedPath, relativePath })
+      }
+      await vault.loadModifiedFiles()
+      await vault.reloadVault()
+    } catch (err) {
+      setToastMessage(typeof err === 'string' ? err : 'Failed to discard changes')
+    }
+  }, [resolvedPath, vault, setToastMessage])
+
   const commitFlow = useCommitFlow({ savePending: appSave.savePending, loadModifiedFiles: vault.loadModifiedFiles, commitAndPush: vault.commitAndPush, setToastMessage, onPushRejected: autoSync.handlePushRejected })
   const suggestedCommitMessage = useMemo(() => generateCommitMessage(vault.modifiedFiles), [vault.modifiedFiles])
 
@@ -579,7 +593,7 @@ function App() {
               {selection.kind === 'filter' && selection.filter === 'pulse' ? (
                 <PulseView vaultPath={resolvedPath} onOpenNote={vaultBridge.handlePulseOpenNote} sidebarCollapsed={!sidebarVisible} onExpandSidebar={() => setViewMode('all')} />
               ) : (
-                <NoteList entries={vault.entries} selection={selection} selectedNote={activeTab?.entry ?? null} noteListFilter={noteListFilter} onNoteListFilterChange={setNoteListFilter} inboxPeriod={inboxPeriod} modifiedFiles={vault.modifiedFiles} modifiedFilesError={vault.modifiedFilesError} getNoteStatus={vault.getNoteStatus} sidebarCollapsed={!sidebarVisible} onSelectNote={notes.handleSelectNote} onReplaceActiveTab={notes.handleReplaceActiveTab} onCreateNote={notes.handleCreateNoteImmediate} onBulkArchive={bulkActions.handleBulkArchive} onBulkTrash={bulkActions.handleBulkTrash} onBulkRestore={bulkActions.handleBulkRestore} onBulkDeletePermanently={deleteActions.handleBulkDeletePermanently} onEmptyTrash={deleteActions.handleEmptyTrash} onUpdateTypeSort={notes.handleUpdateFrontmatter} updateEntry={vault.updateEntry} onOpenInNewWindow={handleOpenEntryInNewWindow} views={vault.views} />
+                <NoteList entries={vault.entries} selection={selection} selectedNote={activeTab?.entry ?? null} noteListFilter={noteListFilter} onNoteListFilterChange={setNoteListFilter} inboxPeriod={inboxPeriod} modifiedFiles={vault.modifiedFiles} modifiedFilesError={vault.modifiedFilesError} getNoteStatus={vault.getNoteStatus} sidebarCollapsed={!sidebarVisible} onSelectNote={notes.handleSelectNote} onReplaceActiveTab={notes.handleReplaceActiveTab} onCreateNote={notes.handleCreateNoteImmediate} onBulkArchive={bulkActions.handleBulkArchive} onBulkTrash={bulkActions.handleBulkTrash} onBulkRestore={bulkActions.handleBulkRestore} onBulkDeletePermanently={deleteActions.handleBulkDeletePermanently} onEmptyTrash={deleteActions.handleEmptyTrash} onUpdateTypeSort={notes.handleUpdateFrontmatter} updateEntry={vault.updateEntry} onOpenInNewWindow={handleOpenEntryInNewWindow} onDiscardFile={handleDiscardFile} views={vault.views} />
               )}
             </div>
             <ResizeHandle onResize={layout.handleNoteListResize} />

src/components/NoteItem.tsx

@@ -152,7 +152,7 @@ function getFileKindIcon(fileKind: string | undefined): ComponentType<SVGAttribu
   return FileText
 }
 
-export function NoteItem({ entry, isSelected, isMultiSelected = false, isHighlighted = false, noteStatus = 'clean', typeEntryMap, onClickNote, onPrefetch }: {
+export function NoteItem({ entry, isSelected, isMultiSelected = false, isHighlighted = false, noteStatus = 'clean', typeEntryMap, onClickNote, onPrefetch, onContextMenu }: {
   entry: VaultEntry
   isSelected: boolean
   isMultiSelected?: boolean
@@ -161,6 +161,7 @@ export function NoteItem({ entry, isSelected, isMultiSelected = false, isHighlig
   typeEntryMap: Record<string, VaultEntry>
   onClickNote: (entry: VaultEntry, e: React.MouseEvent) => void
   onPrefetch?: (path: string) => void
+  onContextMenu?: (entry: VaultEntry, e: React.MouseEvent) => void
 }) {
   const isBinary = entry.fileKind === 'binary'
   const isNonMarkdown = !!entry.fileKind && entry.fileKind !== 'markdown'
@@ -187,6 +188,7 @@ export function NoteItem({ entry, isSelected, isMultiSelected = false, isHighlig
       )}
       style={isBinary ? { padding: '14px 16px' } : noteItemStyle(isSelected, isMultiSelected, typeColor, typeLightColor)}
       onClick={handleClick}
+      onContextMenu={onContextMenu ? (e) => onContextMenu(entry, e) : undefined}
       onMouseEnter={!isBinary && onPrefetch ? () => onPrefetch(entry.path) : undefined}
       data-testid={isMultiSelected ? 'multi-selected-item' : isBinary ? 'binary-file-item' : undefined}
       data-highlighted={isHighlighted || undefined}

src/components/NoteList.test.tsx

@@ -1081,6 +1081,64 @@ describe('NoteList — virtual list with large datasets', () => {
       )
       expect(screen.queryByText(/notes? deleted/)).not.toBeInTheDocument()
     })
+
+    it('shows context menu with "Discard changes" on right-click when onDiscardFile is provided', () => {
+      const onDiscard = vi.fn()
+      render(
+        <NoteList {...defaultFilterProps} entries={mockEntries} selection={changesSelection} selectedNote={null} modifiedFiles={modifiedFiles} onSelectNote={noopSelect} onReplaceActiveTab={noopReplace} onCreateNote={vi.fn()} onDiscardFile={onDiscard} />
+      )
+      const noteItem = screen.getByText('Build Laputa App').closest('[class*="border-b"]')!
+      fireEvent.contextMenu(noteItem)
+      expect(screen.getByTestId('changes-context-menu')).toBeInTheDocument()
+      expect(screen.getByTestId('discard-changes-button')).toBeInTheDocument()
+    })
+
+    it('does not show context menu when onDiscardFile is not provided', () => {
+      render(
+        <NoteList {...defaultFilterProps} entries={mockEntries} selection={changesSelection} selectedNote={null} modifiedFiles={modifiedFiles} onSelectNote={noopSelect} onReplaceActiveTab={noopReplace} onCreateNote={vi.fn()} />
+      )
+      const noteItem = screen.getByText('Build Laputa App').closest('[class*="border-b"]')!
+      fireEvent.contextMenu(noteItem)
+      expect(screen.queryByTestId('changes-context-menu')).not.toBeInTheDocument()
+    })
+
+    it('shows confirmation dialog after clicking "Discard changes"', () => {
+      const onDiscard = vi.fn()
+      render(
+        <NoteList {...defaultFilterProps} entries={mockEntries} selection={changesSelection} selectedNote={null} modifiedFiles={modifiedFiles} onSelectNote={noopSelect} onReplaceActiveTab={noopReplace} onCreateNote={vi.fn()} onDiscardFile={onDiscard} />
+      )
+      const noteItem = screen.getByText('Build Laputa App').closest('[class*="border-b"]')!
+      fireEvent.contextMenu(noteItem)
+      fireEvent.click(screen.getByTestId('discard-changes-button'))
+      expect(screen.getByTestId('discard-confirm-dialog')).toBeInTheDocument()
+      // Dialog mentions the note title
+      const dialog = screen.getByTestId('discard-confirm-dialog')
+      expect(dialog.textContent).toContain('Build Laputa App')
+    })
+
+    it('calls onDiscardFile with relativePath when discard is confirmed', async () => {
+      const onDiscard = vi.fn().mockResolvedValue(undefined)
+      render(
+        <NoteList {...defaultFilterProps} entries={mockEntries} selection={changesSelection} selectedNote={null} modifiedFiles={modifiedFiles} onSelectNote={noopSelect} onReplaceActiveTab={noopReplace} onCreateNote={vi.fn()} onDiscardFile={onDiscard} />
+      )
+      const noteItem = screen.getByText('Build Laputa App').closest('[class*="border-b"]')!
+      fireEvent.contextMenu(noteItem)
+      fireEvent.click(screen.getByTestId('discard-changes-button'))
+      fireEvent.click(screen.getByTestId('discard-confirm-button'))
+      expect(onDiscard).toHaveBeenCalledWith('project/26q1-laputa-app.md')
+    })
+
+    it('does not call onDiscardFile when cancel is clicked', () => {
+      const onDiscard = vi.fn()
+      render(
+        <NoteList {...defaultFilterProps} entries={mockEntries} selection={changesSelection} selectedNote={null} modifiedFiles={modifiedFiles} onSelectNote={noopSelect} onReplaceActiveTab={noopReplace} onCreateNote={vi.fn()} onDiscardFile={onDiscard} />
+      )
+      const noteItem = screen.getByText('Build Laputa App').closest('[class*="border-b"]')!
+      fireEvent.contextMenu(noteItem)
+      fireEvent.click(screen.getByTestId('discard-changes-button'))
+      fireEvent.click(screen.getByText('Cancel'))
+      expect(onDiscard).not.toHaveBeenCalled()
+    })
   })
 })
 

src/components/NoteList.tsx

@@ -1,4 +1,4 @@
-import { useState, useMemo, useCallback, useEffect, memo } from 'react'
+import { useState, useMemo, useCallback, useEffect, useRef, memo } from 'react'
 import type { VaultEntry, SidebarSelection, ModifiedFile, NoteStatus, InboxPeriod, ViewFile } from '../types'
 import type { NoteListFilter } from '../utils/noteListHelpers'
 import { countByFilter, countAllByFilter } from '../utils/noteListHelpers'
@@ -16,6 +16,11 @@ import {
   useTypeEntryMap, useNoteListData, useNoteListSearch,
   useNoteListSort, useMultiSelectKeyboard, useModifiedFilesState,
 } from './note-list/noteListHooks'
+import {
+  Dialog, DialogContent, DialogHeader, DialogTitle,
+  DialogDescription, DialogFooter,
+} from '@/components/ui/dialog'
+import { Button } from '@/components/ui/button'
 
 interface NoteListProps {
   entries: VaultEntry[]
@@ -40,10 +45,11 @@ interface NoteListProps {
   onUpdateTypeSort?: (path: string, key: string, value: string | number | boolean | string[] | null) => void
   updateEntry?: (path: string, patch: Partial<VaultEntry>) => void
   onOpenInNewWindow?: (entry: VaultEntry) => void
+  onDiscardFile?: (relativePath: string) => Promise<void>
   views?: ViewFile[]
 }
 
-function NoteListInner({ entries, selection, selectedNote, noteListFilter, onNoteListFilterChange, inboxPeriod = 'all', modifiedFiles, modifiedFilesError, getNoteStatus, sidebarCollapsed, onSelectNote, onReplaceActiveTab, onCreateNote, onBulkArchive, onBulkTrash, onBulkRestore, onBulkDeletePermanently, onEmptyTrash, onUpdateTypeSort, updateEntry, onOpenInNewWindow, views }: NoteListProps) {
+function NoteListInner({ entries, selection, selectedNote, noteListFilter, onNoteListFilterChange, inboxPeriod = 'all', modifiedFiles, modifiedFilesError, getNoteStatus, sidebarCollapsed, onSelectNote, onReplaceActiveTab, onCreateNote, onBulkArchive, onBulkTrash, onBulkRestore, onBulkDeletePermanently, onEmptyTrash, onUpdateTypeSort, updateEntry, onOpenInNewWindow, onDiscardFile, views }: NoteListProps) {
   const { modifiedPathSet, modifiedSuffixes, resolvedGetNoteStatus } = useModifiedFilesState(modifiedFiles, getNoteStatus)
 
   const isSectionGroup = selection.kind === 'sectionGroup'
@@ -88,9 +94,41 @@ function NoteListInner({ entries, selection, selectedNote, noteListFilter, onNot
   const bulkTrashOrDelete = isTrashView ? handleBulkDeletePermanently : handleBulkTrash
   useMultiSelectKeyboard(multiSelect, isEntityView, bulkArchiveOrRestore, bulkTrashOrDelete)
 
+  // ── Changes view: context menu + discard confirmation ──
+  const [ctxMenu, setCtxMenu] = useState<{ x: number; y: number; entry: VaultEntry } | null>(null)
+  const [discardTarget, setDiscardTarget] = useState<VaultEntry | null>(null)
+  const ctxMenuRef = useRef<HTMLDivElement>(null)
+
+  const handleNoteContextMenu = useCallback((entry: VaultEntry, e: React.MouseEvent) => {
+    if (!isChangesView || !onDiscardFile) return
+    e.preventDefault()
+    e.stopPropagation()
+    setCtxMenu({ x: e.clientX, y: e.clientY, entry })
+  }, [isChangesView, onDiscardFile])
+
+  const closeCtxMenu = useCallback(() => setCtxMenu(null), [])
+
+  // Close context menu on outside click
+  useEffect(() => {
+    if (!ctxMenu) return
+    const handler = (e: MouseEvent) => {
+      if (ctxMenuRef.current && !ctxMenuRef.current.contains(e.target as Node)) closeCtxMenu()
+    }
+    document.addEventListener('mousedown', handler)
+    return () => document.removeEventListener('mousedown', handler)
+  }, [ctxMenu, closeCtxMenu])
+
+  const handleDiscardConfirm = useCallback(async () => {
+    if (!discardTarget || !onDiscardFile) return
+    const mf = modifiedFiles?.find((f) => f.path === discardTarget.path)
+    if (!mf) return
+    await onDiscardFile(mf.relativePath)
+    setDiscardTarget(null)
+  }, [discardTarget, onDiscardFile, modifiedFiles])
+
   const renderItem = useCallback((entry: VaultEntry) => (
-    <NoteItem key={entry.path} entry={entry} isSelected={selectedNote?.path === entry.path} isMultiSelected={multiSelect.selectedPaths.has(entry.path)} isHighlighted={entry.path === noteListKeyboard.highlightedPath} noteStatus={resolvedGetNoteStatus(entry.path)} typeEntryMap={typeEntryMap} onClickNote={handleClickNote} onPrefetch={prefetchNoteContent} />
-  ), [selectedNote?.path, handleClickNote, typeEntryMap, resolvedGetNoteStatus, multiSelect.selectedPaths, noteListKeyboard.highlightedPath])
+    <NoteItem key={entry.path} entry={entry} isSelected={selectedNote?.path === entry.path} isMultiSelected={multiSelect.selectedPaths.has(entry.path)} isHighlighted={entry.path === noteListKeyboard.highlightedPath} noteStatus={resolvedGetNoteStatus(entry.path)} typeEntryMap={typeEntryMap} onClickNote={handleClickNote} onPrefetch={prefetchNoteContent} onContextMenu={isChangesView && onDiscardFile ? handleNoteContextMenu : undefined} />
+  ), [selectedNote?.path, handleClickNote, typeEntryMap, resolvedGetNoteStatus, multiSelect.selectedPaths, noteListKeyboard.highlightedPath, isChangesView, onDiscardFile, handleNoteContextMenu])
 
   const handleCreateNote = useCallback(() => {
     onCreateNote(selection.kind === 'sectionGroup' ? selection.type : undefined)
@@ -115,6 +153,35 @@ function NoteListInner({ entries, selection, selectedNote, noteListFilter, onNot
       {multiSelect.isMultiSelecting && (
         <BulkActionBar count={multiSelect.selectedPaths.size} isTrashView={isTrashView} isArchivedView={isArchivedView} onArchive={handleBulkArchive} onTrash={handleBulkTrash} onRestore={handleBulkRestore} onDeletePermanently={handleBulkDeletePermanently} onUnarchive={handleBulkUnarchive} onClear={multiSelect.clear} />
       )}
+
+      {/* Changes view: context menu */}
+      {ctxMenu && (
+        <div ref={ctxMenuRef} className="fixed z-50 rounded-md border bg-popover p-1 shadow-md" style={{ left: ctxMenu.x, top: ctxMenu.y, minWidth: 180 }} data-testid="changes-context-menu">
+          <button
+            className="flex w-full items-center gap-2 rounded-sm px-2 py-1.5 text-sm cursor-default hover:bg-accent hover:text-accent-foreground transition-colors border-none bg-transparent text-left text-destructive"
+            onClick={() => { setDiscardTarget(ctxMenu.entry); closeCtxMenu() }}
+            data-testid="discard-changes-button"
+          >
+            Discard changes
+          </button>
+        </div>
+      )}
+
+      {/* Discard confirmation dialog */}
+      <Dialog open={!!discardTarget} onOpenChange={(open) => { if (!open) setDiscardTarget(null) }}>
+        <DialogContent showCloseButton={false} data-testid="discard-confirm-dialog">
+          <DialogHeader>
+            <DialogTitle>Discard changes</DialogTitle>
+            <DialogDescription>
+              Discard changes to <strong>{discardTarget?.title ?? 'this file'}</strong>? This cannot be undone.
+            </DialogDescription>
+          </DialogHeader>
+          <DialogFooter>
+            <Button variant="outline" onClick={() => setDiscardTarget(null)}>Cancel</Button>
+            <Button variant="destructive" onClick={handleDiscardConfirm} data-testid="discard-confirm-button">Discard</Button>
+          </DialogFooter>
+        </DialogContent>
+      </Dialog>
     </div>
   )
 }

src/mock-tauri/mock-handlers.ts

@@ -155,6 +155,7 @@ export const mockHandlers: Record<string, (args: any) => any> = {
   },
   get_file_diff: (args: { path: string }) => mockFileDiff(args.path),
   get_file_diff_at_commit: (args: { path: string; commitHash: string }) => mockFileDiffAtCommit(args.path, args.commitHash),
+  git_discard_file: () => {},
   git_commit: (args: { message: string }) => {
     const count = (mockHasChanges ? mockModifiedFiles().length : 0) + mockSavedSinceCommit.size
     mockHasChanges = false