cliedit

A lightweight, zero-dependency, raw-mode terminal editor component for Node.js.

cliedit is designed to be imported into your own CLI application to provide a full-featured, TTY-based text editing experience. It's perfect for applications that need to ask the user for multi-line input, edit configuration files, or write commit messages.

It includes line wrapping, visual navigation, smart auto-indentation, undo/redo, text selection, Find/Replace, and cross-platform clipboard support.

A CodeTease project.

Features

• Raw Mode TTY: Takes over the terminal for a full "app-like" feel.
• Visual Line Wrapping: Text wraps to fit the terminal width.
• Visual Navigation: Up/Down arrows move by visual rows, not logical lines.
• Undo/Redo: Ctrl+Z / Ctrl+Y for persistent history.
• Text Selection: Ctrl+Arrow keys to select text.
• Clipboard Support: Ctrl+C (Copy), Ctrl+X (Cut), Ctrl+V (Paste) for system clipboard (macOS, Windows, and Linux via xclip).
• Syntax Highlighting: Lightweight highlighting for Brackets () [] {} and Strings "" ''.
• File I/O: Loads from and saves to the filesystem.
• Search & Replace: Ctrl+W to find text, Ctrl+R to find and replace interactively.
• Go to Line: Ctrl+L to quickly jump to a specific line number.
• Smart Auto-Indentation: Automatically preserves indentation level when pressing Enter.
• Block Indentation: Use Tab / Shift+Tab to indent or outdent selected blocks of text.
• Smart Navigation: Alt + Left/Right to jump by words, Ctrl + M to jump between matching brackets.
• Line Moving: Alt + Up/Down to move the current line or selection up and down.
• Line Duplication: Ctrl+D to duplicate the current line or selection.
• Piping Support: Works with standard Unix pipes (e.g. cat file.txt | cliedit).
• Crash Recovery: Automatically saves changes to a hidden swap file (e.g. .filename.swp) to prevent data loss.

Architecture Improvements

cliedit employs a optimization strategy to handle large files efficiently while maintaining a responsive UI:

• Math-Only Viewport: Rendering is stateless. The editor calculates visual wrapping on the fly (Virtual Scrolling) rather than storing a massive state array, significantly reducing memory usage for large documents.
• Screen Buffer Diffing: A double-buffering system compares the current and next frame to send only the changed characters to the terminal, minimizing I/O and eliminating flicker.
• Worker Threads: Syntax highlighting runs asynchronously in a background Worker Thread, preventing UI freezes during rendering of complex lines.
• Recommended Limits: Good for files up to 50k lines (perfect for configs, scripts, and logs).

Installation

npm install cliedit

Usage

The package exports an async function openEditor that returns a Promise. The promise resolves when the user quits the editor.

import { openEditor } from 'cliedit';
import path from 'path';

async function getCommitMessage() {
  const tempFile = path.resolve(process.cwd(), 'COMMIT_MSG.txt');
  
  // Example with custom options
  const options = {
    tabSize: 2,
    gutterWidth: 3
  };

  try {
    const result = await openEditor(tempFile, options);

    if (result.saved) {
      console.log('Message saved:', result.content);
    } else {
      console.log('Editor quit without saving.');
    }
  } catch (err) {
    console.error('Editor failed:', err);
  }
}

getCommitMessage();

Piping Support

cliedit supports standard input piping. When used in a pipeline, it reads the input content, then re-opens the TTY to allow interactive editing.

# Edit a file using cat
cat README.md | node my-app.js

# Edit the output of a command
git diff | node my-app.js

Public API

openEditor(filepath: string, options?: EditorOptions)

Opens the editor for the specified file.

• filepath: Path to the file to edit.
• options: (Optional) Configuration object.

  • tabSize: Number of spaces for a tab (default: 4).

  • gutterWidth: Width of the line number gutter (default: 5).

  • Returns: Promise<{ saved: boolean; content: string }>

    • saved: true if the user saved (Ctrl+S), false otherwise (Ctrl+Q).
    • content: The final content of the file as a string.

Crash Recovery

cliedit includes a built-in safety mechanism. It periodically saves the current content to a hidden swap file (e.g., .myfile.txt.swp) in the same directory.

If the process crashes or is terminated abruptly, the next time you open the file, cliedit will detect the swap file and automatically recover the unsaved content, displaying a RECOVERED FROM SWAP FILE message.

• Returns: Promise<{ saved: boolean; content: string }>
  • saved: true if the user saved (Ctrl+S), false otherwise (Ctrl+Q).
  • content: The final content of the file as a string.

CliEditor

The main editor class. You can import this directly if you need to extend or instantiate the editor with custom logic.

import { CliEditor } from 'cliedit';

Types

Key types are also exported for convenience:

import type {
  DocumentState,
  EditorMode,
  NormalizedRange,
} from 'cliedit';

Acknowledgements

Please see the ACKNOWLEDGEMENTS.md file for important copyright information regarding the vendored keypress component.

License

MIT