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Namasivaayam L
Namasivaayam L

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Why Global Undo Sucks: Building Line-Level Undo/Redo for VS Code

1. The Problem: Why Global Undo Fails Devs 😤

If you’ve been using VS Code long enough, you’ve probably had this moment:

You’re editing two different parts of a file.

You spot a typo on one line.

You hit Ctrl + Z.

Suddenly, something completely unrelated disappears.

Nothing is technically broken — but your flow is. 🫠

Global undo is time-based.

It rewinds your editor to a previous point in history, regardless of what you were trying to undo.

But developers don’t think in time.

We think in intent.

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

Instead, global undo answers a different question:

“What was the last edit operation?”

That mismatch is the entire reason Ghost Line exists.


2. Using Ghost Line 👻 (Start Here)

Ghost Line doesn’t replace native undo.

It runs alongside it, without interfering.

The core idea is simple:

Undo or redo only the current line, nothing else.


2.1 Keyboard Shortcuts ⌨️

Ghost Line is designed to be muscle-memory friendly.

  • Line UndoCtrl + Alt + Z
  • Line RedoCtrl + Alt + Y
  • List Line Undo HistoryCtrl + Shift + Alt + Z
  • List Line Redo HistoryCtrl + Shift + Alt + Y

📸 Screenshot – VS Code Keyboard Shortcuts
Show line undo, redo, list undo, list redo bindings


2.2 Line-Level Undo / Redo in Action 🎥

In this clip, I’m undoing and redoing changes only on the current line, without affecting the rest of the file.

I then open the line-level history picker to preview and restore a previous version of that line — no global undo, no collateral damage. 👻

📽 Demo – Line-Level Undo / Redo + History Picker

Ghost Line Demo


2.3 Configuration That Actually Matters ⚙️

Ghost Line keeps configuration minimal and purposeful.

  • Max history per line:
    Limits how many snapshots are stored per line.

  • Idle delay:
    Controls how aggressively snapshots are captured.

  • Shortcut toggle:
    Lets you disable Ghost Line keybindings without uninstalling the extension.

No settings bloat.

No micro-tuning obsession.

📸 Screenshot – VS Code Settings (Ghost Line Configuration)

ghostLine.maxHistoryPerLine, idleDelay, and enableShortcuts

3. How Ghost Line Works (High-Level) 🧠

This blog focuses on usage, but at a high level:

  • Each line maintains its own undo/redo history
  • History is snapshot-based, not diff-based
  • Line undo runs safely alongside native VS Code undo

The internals deserve their own deep dive — this post is about getting value fast.


4. Edge Cases, Limitations, and What’s Next 🧩


4.1 Edge Cases Handled

Some problems are unavoidable — but manageable:

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

Ghost Line takes care to keep history consistent even when the file structure changes 🔄.


4.2 Current Limitations ⚠️

Ghost Line is precise — not magical.

Right now:

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

This is intentional scope control, not missing ambition.


4.3 What’s Coming Next 🚧

Planned improvements include:

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

No timelines.

No promises.

Just direction 🧭.


5. Conclusion: Undo Should Respect Intent 🎯

Global undo optimizes for simplicity.

Developers optimize for flow.

Ghost Line is an experiment in intent-aware editing — undoing what you meant to undo, not whatever happened last.

This kind of feature belongs in extensions first.

That’s where ideas get tested, broken, and refined.

If global undo ever gets smarter, great.

Until then, Ghost Line exists for those moments when precision matters 👻.


Thanks & Links 🙌

Thanks for reading!

Ghost Line started as a small experiment to fix a daily annoyance and slowly turned into a focused attempt at making undo feel less destructive.

If this resonated with you — or if Ctrl + Z has ever betrayed you — I’d love your feedback.

  • Issues / Feature Requests: Bugs, edge cases, and ideas are always welcome.
  • Contributions: PRs are appreciated, especially around correctness, UX, and edge cases.
  • Discussion: Let's start discussing in the comments below 😄
  • GitHub Repository: https://github.com/Namasivaayam-L/ghost-line
  • VS Code Extension: Ghost Line

It’s an open-source project, built in public.

If it saves you even one unnecessary undo — mission accomplished 👻✨

P.S. A quick request! 📝

This is actually my first-ever technical blog post. I tried to keep it concise and respectful of your time, but I’m still learning.

I would genuinely appreciate feedback on the structure and writing style—let me know in the comments if the flow worked for you or if I should change things up for the next one!

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