Project 21: Virtual Terminal

📋 Project Brief

Build a web-based terminal emulator that looks and behaves like a real command line interface. Implement a virtual file system, command history navigation, tab completion, and custom theming. This project demonstrates advanced string parsing and state management.

✅ Feature Requirements

Feature 1: Command History

Acceptance Criteria:

• Pressing ↑ cycles through previous commands (most recent first)
• Pressing ↓ cycles forward through history
• History persists in localStorage (max 100 entries)
• A history command lists all previous commands
• history clear wipes the history

Feature 2: Virtual File System

Acceptance Criteria:

• ls — lists files and folders in the current directory
• cd <dir> — changes directory; cd .. goes up one level
• mkdir <name> — creates a new directory
• touch <name> — creates a new file
• cat <file> — displays file contents
• rm <name> — removes a file or empty directory
• pwd — prints the current working directory
• The file system is represented as a nested JavaScript object and persists in localStorage

Feature 3: Terminal Theming

Acceptance Criteria:

• Preset themes: "Classic Green" (green on black), "Matrix" (green rain animation), "Ubuntu" (purple/orange), "Dracula"
• A theme <name> command switches themes
• Custom prompt format: user@terminal:~/path $
• Font must be monospace; support for font size adjustment

Feature 4: Tab Completion

Acceptance Criteria:

• Pressing Tab auto-completes command names and file/directory names
• If multiple matches exist, show all options (like bash)
• Double-Tab lists all available commands

Feature 5: Special Commands

Acceptance Criteria:

• help — lists all available commands with descriptions
• clear — clears the terminal output
• echo <text> — prints text to the terminal
• date — shows current date and time
• whoami — displays the "username"
• sudo <anything> — triggers a fun "Access Denied" animation

📊 Command Parser Requirements

Input	Parsed As
ls	{ command: "ls", args: [] }
cd documents	{ command: "cd", args: ["documents"] }
echo "hello world"	{ command: "echo", args: ["hello world"] }
mkdir "my folder"	{ command: "mkdir", args: ["my folder"] }

🧪 Testing Checklist

• Unit test command parser (handling quotes, spaces, special characters)
• Unit test file system operations (create, delete, navigate)
• Unit test tab completion algorithm
• Integration test: create a folder, navigate into it, create a file, cat it
• A11y: terminal output must be accessible to screen readers via aria-live

🚀 Stretch Goals

• Add pipe support: ls | grep .txt
• Implement nano <file> — a simple in-terminal text editor
• Add command aliases
• Implement a "boot sequence" animation on first load