Testing Checklist

Items marked ✅ are covered by automated UI integration tests (tests/ui_integration/).

CLI / Launch Modes

Welcome Window

"Compare Files" button: two file dialogs, then opens diff; welcome closes
"Compare Directories" button: two folder dialogs, then opens dir window; welcome closes
"3-way Merge" button: three file dialogs, then opens merge; welcome closes
Preferences button / Ctrl+,: opens Preferences dialog
Ctrl+W: closes welcome window
Ctrl+N: opens a new welcome window
Cancel any file dialog: nothing happens

File Diff (2-way)

Display

Chunk backgrounds: blue for replace, green for insert/delete
Current chunk: bold dark borders when navigating
Inline word-level highlighting: yellow (changed), pink (deleted), green (inserted)
Filler lines: thin colored lines where the other side has more content
Gutter: curved connecting bands between panes
Chunk map strips: minimap of changes at far edges; clickable to jump
Chunk map viewport indicator: visible rectangle showing current scroll position
Syntax highlighting: detected from filename
Line numbers: shown/hidden per settings

Toolbar

Gutter Interactions

Click right arrow: copies left chunk to right
Click left arrow: copies right chunk to left
Right-click gutter: context menu with both copy options
Paste highlight flash: 500ms blue flash on inserted text

Scroll Sync

Horizontal scroll synced between panes
Vertical scroll synced by chunk between panes

Find / Replace

✅ Ctrl+F: opens find bar; Ctrl+H: opens find + replace
Typing highlights all matches in both buffers; shows match count
Find next (F3 / Enter) / Find prev (Shift+F3): wraps around
F3/Shift+F3 works from find entry, replace entry, and source pane
✅ Escape closes find bar from source pane (not just from find entry)
Replace: replaces current selection if it matches
Replace All: replaces in both buffers
Close (X / Escape): hides bar, clears highlights, returns focus to pane
After closing find bar, Ctrl+F / Ctrl+H work immediately

Save

File Watcher

External file change: auto-reloads if no unsaved changes
External change while unsaved: reload skipped
Save suppresses reload for 600ms (no reload loop)

Close / Dialogs

Ctrl+W: closes window
Close with no unsaved changes: closes immediately
Close with unsaved changes: dialog with per-file checkboxes, Save/Close without Saving/Cancel
Save failure in dialog: window does NOT close
Overwrite confirm dialog: Escape key closes it
Ctrl+Shift+P: export patch dialog opens (sourceview doesn't consume it)

Chunk Copy (Alt+Left / Alt+Right)

Alt+Right on a diff chunk: copies left chunk content to right (no file copy dialog)
Alt+Left on a diff chunk: copies right chunk content to left (no file copy dialog)
Alt+Left/Right with no current chunk: nothing happens
In file diff tab opened from dir window: Alt+Left/Right copies chunks, does NOT trigger dir file copy

Chunk Pull (Alt+Shift+Left / Alt+Shift+Right)

Alt+Shift+Right: pulls content from right pane into focused pane
Alt+Shift+Left: pulls content from left pane into focused pane
Pull when focused on the same side as pull direction: no-op

Delete Change (Alt+Delete)

✅ Alt+Delete: deletes the current chunk's text from the focused pane
Alt+Delete with no current chunk: nothing happens
Alt+Delete at end of buffer: removes preceding newline too

Pane Switching (Alt+PageUp / Alt+PageDown)

✅ Alt+PageDown: switches focus to next pane (wraps around)
✅ Alt+PageUp: switches focus to previous pane (wraps around)
In 3-way merge: cycles left→middle→right→left

Fullscreen (F11)

✅ F11: toggles fullscreen mode
✅ F11 again: exits fullscreen

Edge Cases

✅ Identical files: "Files are identical" info bar; edit one side -> bar disappears; undo -> reappears
✅ Binary files: info bar, panes read-only, patch button disabled, swap/nav/blanks/spaces/undo/redo buttons disabled
Empty files: no chunks, label shows "No changes"
✅ Empty file vs non-empty file: all-insert chunks on one side
Very large files (10K+ lines): background diff, UI stays responsive
UTF-8 with multi-byte characters: inline highlighting correct
✅ Files with only whitespace differences + Spaces toggle on: no differences shown
✅ Files with only blank line differences + Blanks toggle on: no differences shown
✅ Swap panes twice: returns to original state

Navigation

✅ Alt+Up/Down: cursor moves to chunk start line
Click in pane, then Alt+Down: navigates from cursor position, not from top
Navigate chunks with cursor in different positions: cursor-aware seeking
Alt+Up/Down intercepted: sourceview move-lines action does not fire
Wrap-around navigation: Alt+Down past last chunk wraps to first (if enabled in prefs)
✅ Wrap-around off: Alt+Down on last chunk stays; Alt+Up on first chunk stays

Directory Comparison

Display

✅ Tree view with expandable directories
Columns: Name (with icon), Size, Modification time
Directory headers above each pane with full path as tooltip
Copy path button next to each header: copies full absolute path to clipboard
Copy path after swap: copies the swapped (current) path, not the original
Status colors: blue (different), orange (left-only), green (right-only), red (conflict), dim italic (missing side)

Navigation

✅ Double-click file row: opens diff in new notebook tab
Enter on file row: opens diff in new notebook tab
✅ Enter on directory row: expands/collapses folder
Enter after closing a file tab: still works (no broken activation state)
Left/Right arrow keys: switch focus between panes
Selection syncs between panes (highlighted on both sides)
Active pane: accent-color border; inactive pane: dim border + reduced opacity
Switching panes: no scroll jump, keyboard cursor syncs to selected row

Toolbar

Context Menu

Right-click selects the clicked row first
Right-click targets correct row: select row A, right-click row B, action operates on B (not A)
"Open Diff": opens diff tab (disabled for directories)
"Copy to Left" / "Copy to Right": enabled for appropriate statuses
"Delete": enabled only when file exists on focused side
"Open Externally" / "Copy File Path": enabled only when file exists on focused side
Missing-side file: Copy, Delete, Open Externally, Copy Path all disabled

Notebook Tabs

File Watcher

Directory rescans on FS changes (500ms poll)
Expanded directories and selection restored after rescan
Open tab buffers reloaded unless unsaved

Filters

Filtered names (.git, node_modules, etc.) excluded from tree
Custom filters from preferences applied
Hide hidden files on (default): dotfiles excluded from tree
Hide hidden files off: dotfiles shown in tree

Edge Cases

Collapse all with missing-side files expanded: no crash
Deeply nested directory trees
Copy directory recursively: all nested files copied
Dir -> file tab -> swap -> edit -> save dialog shows correct filename
Window close with unsaved tabs: dialog lists all unsaved files

3-Way Merge

Display

✅ Three panes: left (read-only), middle (editable), right (read-only)
✅ Left/right save buttons hidden; only middle has save button
Left gutter: bands connecting left to middle
Right gutter: bands connecting middle to right
Conflict backgrounds: red/pink overlays on middle where left/right overlap
Chunk maps on both edges

Toolbar

✅ Undo/Redo (Ctrl+Z / Ctrl+Shift+Z): acts on active pane
✅ Previous/Next change (Alt+Up/Down): per-pane cursor-based navigation
Navigation only places cursor on involved panes (not the third uninvolved pane)
Previous/Next conflict (Ctrl+J / Ctrl+K): navigates <<<<<<< markers in middle
Conflict label: "N conflicts" / "Conflict X of N" / "No conflicts"
Go to line (Ctrl+L)
✅ Blanks / Spaces toggles
Preferences (Ctrl+,)

Gutter Interactions

Only inward arrows: left gutter has right-arrows only, right gutter has left-arrows only
Click left gutter arrow: copies left chunk into middle
Click right gutter arrow: copies right chunk into middle
Right-click context menus: "Copy Left -> Middle" / "Copy Right -> Middle"

Scroll Sync

Horizontal sync across all three panes
Vertical scroll synced by chunk across all three panes

Find / Replace

Ctrl+F/H: find bar highlights matches across all three buffers
Match count sums all three buffers
Replace All replaces only in editable middle buffer (not read-only left/right)

Save

✅ Ctrl+S: saves middle pane
Ctrl+Shift+S (Save As): saves middle to a new path; updates pane label
Save As updates tab-tracked path (close/unsaved dialog shows new name)
Ctrl+Shift+L (Save All): saves middle if dirty
Ctrl+Shift+O: opens focused file externally (works for all 3 panes)
Ctrl+R / F5 (Refresh): reloads all 3 files from disk
Refresh with unsaved middle: confirm dialog before reloading
After Save As, watcher reloads from new path (left/right still watch originals)

Edge Cases

Binary files: all panes show info bar; all read-only; middle save hidden
All three identical: no changes, no chunks
Both sides modify same region: conflict overlay on middle
Copy left then copy right to same region: middle updates; undo works
Undo/redo across panes: applies to active pane's buffer

VCS (Git) Window

Display

✅ Window title: "mergers — reponame (branchname)"
✅ Branch name shown in toolbar
ColumnView: Status, File, and Extra columns
Status colors: Modified/Renamed = blue, Added/Untracked = green, Deleted = orange
✅ Extra column: "Staged" for fully staged, "Partially staged" for staged+unstaged
✅ Conflict files: Extra column empty (not falsely "Staged")
✅ Repo path label and changed file count

Opening Diffs

✅ Double-click / Enter: opens diff tab (HEAD vs working copy)
Modified/Renamed: HEAD content on left, working file on right
Added/Untracked: empty left, working file on right
Deleted: HEAD content on left, empty right
Already-open tab: switches to existing tab

Context Menu

Right-click selects clicked row
"Open Diff": opens diff (disabled for Untracked)
"Discard Changes": runs git checkout -- with confirmation (disabled for Untracked)
"Stage": runs git add (disabled when already staged)
"Stage" on conflicted file: confirmation dialog warning it marks conflict resolved
"Unstage": runs git restore --staged (enabled only when staged)
"Trash": moves to trash with confirmation (Untracked only)

Commit Dialog

✅ Commit button in toolbar
Commit dialog shows branch name
Commit dialog lists staged files (read-only)
Commit dialog prefills message from .git/MERGE_MSG
Commit button disabled when no staged files or empty message
Successful commit refreshes file list

Status Filters

✅ Modified toggle (on by default): shows M, A, D, R, C files
✅ Untracked toggle (on by default): shows U files
Ignored toggle (off by default): shows ignored files
Toggling filters updates file list and count label

File Watcher

Auto-refresh on FS changes (500ms poll)
.git directory events ignored
Smart update: skips rebuild if status unchanged

Notebook / Close

✅ "Changes" tab first; Ctrl+W on it closes window
Ctrl+W on file tab: closes tab with unsaved check
Window close: checks all tabs for unsaved changes
Temp directory cleaned up on window destroy
Alt+1..9: switches to tab by index
Ctrl+N: opens New Comparison tab

Security

Paths with .. components refused

Patch Viewing / Applying

CLI

✅ mergers file.c patch.diff: opens single-file patch view (original vs patched)
✅ mergers dir/ patch.diff: opens multi-file patch view (dir comparison)
✅ .diff extension auto-detected as patch mode
✅ Ctrl+W closes patch window cleanly
-L labels applied to patch views
Invalid patch file: error dialog shown
Base path does not exist: error dialog shown

Single-File Patch

✅ Window title contains "patch" and base filename
✅ Two text panes shown
✅ Left pane: original file content; Right pane: patched result
✅ Right pane contains inserted lines from patch
✅ Chunk label shows change count
✅ Tab label contains "patch"
Conflict hunks shown with <<<<<<< original / >>>>>>> patch markers in right pane
Labels show base filename and "filename (patched)" (not temp paths)
Window destroy cleans up temp directory

Multi-File Patch (Dir View)

Apply All (Dir Patch View)

⏪ button: confirmation dialog shows file count
Modified files (Different): copied right → left through symlink, then removed from view
New files (RightOnly): created in original directory, parent dirs created as needed
Deleted files (LeftOnly): removed from original directory
Conflicted files: skipped (not applied)
View reloads after apply; applied files vanish from tree
File watcher suppressed during bulk copy (no spurious reloads)
Errors during apply: error dialog shown with details

Temp Directory Cleanup

Normal window close: temp dir removed (connect_shutdown)
SIGINT (Ctrl+C): temp dir removed (ctrlc handler)
SIGTERM (kill): temp dir removed (ctrlc handler)
Multiple patch windows: all temp dirs tracked and cleaned up

Preferences

Window State Persistence

✅ Window size saved to settings.toml on close
Window maximized state restored on relaunch
Window fullscreen state restored on relaunch (macOS green button)
Per-window default sizes: VCS=700×500, merge=1200×600, file diff=900×600, dir=900×600
Old configs without window fields get sentinel defaults (0 = use per-window default)
Size only saved when not maximized/fullscreen (avoids saving inflated dimensions)

Dark Mode

Linux/GNOME: auto-detects system dark mode
macOS: falls back to defaults read -g AppleInterfaceStyle
Sets gtk_application_prefer_dark_theme for GTK widgets

Global Shortcuts

Shortcut	Action
Ctrl+Q	Quit (close all windows)
Ctrl+W	Close current tab/window
Ctrl+,	Preferences
Ctrl+Z	Undo
Ctrl+Shift+Z	Redo
Alt+Up / Ctrl+E	Previous change
Alt+Down / Ctrl+D	Next change
Ctrl+J	Previous conflict (merge only)
Ctrl+K	Next conflict (merge only)
Ctrl+F	Find
Ctrl+H (Cmd+Shift+H on macOS)	Find + Replace
F3	Find next
Shift+F3	Find previous
Ctrl+L	Go to line
Alt+PageUp	Previous pane
Alt+PageDown	Next pane
Alt+Shift+Left	Pull chunk from left
Alt+Shift+Right	Pull chunk from right
Alt+Delete	Delete current chunk
F11	Toggle fullscreen
Ctrl+Shift+P	Export patch (file diff only)
Alt+Left	Copy chunk right→left (file diff) / Copy file to left (dir)
Alt+Right	Copy chunk left→right (file diff) / Copy file to right (dir)
Ctrl+S	Save active pane
Ctrl+Shift+S	Save As (file diff / merge)
Ctrl+Shift+L	Save All dirty panes
Ctrl+Shift+O	Open focused file externally
Ctrl+R / F5	Refresh (reload from disk)
Ctrl+N	New Comparison tab (dir/VCS windows)
Alt+1..9	Switch to tab by index (notebook windows)
Delete	Delete selected (dir only)
Enter	Open selected file / expand-collapse dir (dir/VCS)
Escape	Close find bar / go-to-line / preferences dialog

Preferences — Keyboard Shortcuts

"Keyboard Shortcuts" button in Preferences: opens shortcuts dialog
Dialog lists all shortcuts grouped by category

FilesExpand file tree

TESTING.md

Latest commit

History

TESTING.md

File metadata and controls

Testing Checklist

CLI / Launch Modes

Welcome Window

File Diff (2-way)

Display

Toolbar

Gutter Interactions

Scroll Sync

Find / Replace

Save

File Watcher

Close / Dialogs

Chunk Copy (Alt+Left / Alt+Right)

Chunk Pull (Alt+Shift+Left / Alt+Shift+Right)

Delete Change (Alt+Delete)

Pane Switching (Alt+PageUp / Alt+PageDown)

Fullscreen (F11)

Edge Cases

Navigation

Directory Comparison

Display

Navigation

Toolbar

Context Menu

Notebook Tabs

File Watcher

Filters

Edge Cases

3-Way Merge

Display

Toolbar

Gutter Interactions

Scroll Sync

Find / Replace

Save

Edge Cases

VCS (Git) Window

Display

Opening Diffs

Context Menu

Commit Dialog

Status Filters

File Watcher

Notebook / Close

Security

Patch Viewing / Applying

CLI

Single-File Patch

Multi-File Patch (Dir View)

Apply All (Dir Patch View)

Temp Directory Cleanup

Preferences

Window State Persistence

Dark Mode

Global Shortcuts

Preferences — Keyboard Shortcuts