👻 Ghost Line

Intent-aware, line-level undo & redo for VS Code.

Global undo (Ctrl + Z) is powerful — and often destructive. Ghost Line gives you surgical undo: revert only the current line, without touching anything else.

Built for developers who think in intent, not timestamps.

Why Ghost Line Exists 😤

You’ve been here before:

• You’re editing multiple parts of a file
• You notice a typo on one line
• You press Ctrl + Z
• Something unrelated disappears

Nothing is technically broken — but your flow is.

That’s because global undo is time-based. It answers the question:

“What was the last edit operation?”

But developers think differently:

• “Undo this line”
• “Revert that typo”
• “Bring back what this line used to be”

This mismatch is exactly why Ghost Line exists.

What Ghost Line Does 👻

Ghost Line runs alongside native undo, without interfering with it.

Core idea:

Undo or redo only the current line, nothing else.

• No global rewind
• No collateral damage
• No broken mental context

Features ✨

• Line-level undo / redo

  • Undo or redo changes on the active line only

• Independent history per line

  • Each line maintains its own undo & redo stack

• Snapshot-based history

  • Tracks meaningful states, not raw keystrokes

• Debounced capture

  • Saves snapshots after typing pauses (default: 400ms)

• Line-shift aware

  • History follows lines across inserts, deletes, and pastes

• Zero interference with native undo

  • Global Ctrl + Z continues to work as usual

Keyboard Shortcuts ⌨️

Designed to be muscle-memory friendly.

All shortcuts are fully configurable in VS Code.

Line-Level Undo / Redo in Action 🎥

Undoing and redoing only the current line, without affecting the rest of the file. You can also open a line-level history picker to preview and restore previous versions of that line.

Configuration ⚙️

Ghost Line keeps configuration minimal and intentional.

Available settings:

• Max history per line Limits how many snapshots are stored per line
• Idle delay Controls how aggressively snapshots are captured
• Enable shortcuts Toggle Ghost Line keybindings without uninstalling

No settings bloat. No micromanagement.

How It Works (High-Level) 🧠

• Each line maintains its own undo/redo history

• History is snapshot-based, not diff-based

• Snapshots are captured:

  • after typing pauses (debounced)
  • when you move the cursor onto a line

• Undo/redo restores snapshots only for the active line

This design avoids VS Code API pitfalls and keeps behavior predictable.

Architectural Model

History is stored as:

Map<FileURI, Map<LineNumber, LineHistory>>

interface LineHistory {
  undoStack: string[];
  redoStack: string[];
  currentSnapshot: string;
}

• History is per file, per line
• Line history follows lines when they move
• Deleted lines have their history dropped
• Programmatic edits are guarded to avoid feedback loops

Explicit Non-Goals

Ghost Line does not guarantee deterministic behavior for:

• Multi-cursor edits
• Large refactors
• Format-on-save
• AI / agent-driven bulk edits

Behavior in these cases is:

• Best-effort
• Non-crashing
• Non-corrupting

These boundaries are intentional.

Stability Status

Verified

• Idle snapshot capture
• History cap enforcement
• Per-line undo / redo correctness
• Branching behavior
• History restore via QuickPick
• Shortcut gating

Known Limitations (Accepted)

• No multi-cursor semantics
• No agent-aware heuristics

Edge Cases & Limitations ⚠️

Handled Safely

• Line number shifts due to inserts or deletes
• Redo invalidation after new edits
• Safe no-ops when no history exists
• Zero interference with native undo

Current Limitations

• No block or range-based undo
• Multi-line edits are not first-class citizens
• History is session-scoped (not persisted across reloads)

These are intentional scope decisions, not oversights.

What’s Coming Next 🚧

Planned directions (no promises, just intent):

• Hover previews for undo / redo states
• Better multi-line awareness

Installation 📦

From VS Code Marketplace

👉 Ghost Line on VS Code Marketplace

From Source

git clone https://github.com/Namasivaayam-L/ghost-line
cd ghost-line
npm install
npm run compile

Press F5 in VS Code to launch the Extension Development Host.

Contributing & Feedback 🙌

Ghost Line is open-source and built in public.

• Issues / Feature Requests Bugs, edge cases, and ideas are welcome

• Pull Requests Especially around correctness, UX, and edge cases

• Discussions If undo has ever betrayed you — you belong here 😄

• GitHub: https://github.com/Namasivaayam-L/ghost-line

• Marketplace: https://marketplace.visualstudio.com/items?itemName=namachu.ghost-line

If Ghost Line saves you even one unnecessary undo, mission accomplished 👻✨