TypeScript CLI Task Manager

A professional, statically-typed Command Line Interface (CLI) application for managing tasks. Built entirely with native Node.js and TypeScript, this project features a modular architecture, robust error handling, and persistent local data storage.

🚀 Features

• Strictly Typed: Full TypeScript implementation utilizing custom types and interfaces.
• Modular Architecture: Business logic, data layers, and routing are strictly separated for maintainability.
• Persistent Storage: Reads and writes to a local data.json file using Node's native fs and path modules.
• Zero Dependencies: Built without heavy external CLI frameworks (like Yargs or Commander) to demonstrate core Node.js routing and string parsing fundamentals.

📂 Project Structure

ts-cli-task-manager/
├── data/
│   └── data.json           # Local database (git-ignored)
├── functions/
│   ├── add.ts              # Logic for creating tasks
│   ├── complete.ts         # Logic for marking tasks as done
│   ├── delete.ts           # Logic for deleting tasks
│   ├── list.ts             # Logic for listing all tasks
│   └── listfilter.ts       # Logic for filtering tasks by status
├── types.ts                # TypeScript interfaces (Task, Status)
├── db.ts                   # Data layer: handles fs read/write operations
├── main.ts                 # Application entry point and CLI router
├── package.json
├── tsconfig.json
└── .gitignore

🛠️ Prerequisites

To run this project natively without pre-compiling, you need to use tsx (TypeScript Execute).

Install tsx globally on your machine:

npm install -g tsx

💻 Usage

Run the application through your terminal using the tsx main.ts command followed by your desired action.

1. Add a Task

Creates a new task and sets its status to pending.

tsx main.ts add "Learn TypeScript Architecture"

2. Complete a Task

Marks an existing task's status as done using its ID.

tsx main.ts complete 1

3. Delete a Task

Marks a task's status as deleted using its ID.

tsx main.ts delete 1

4. List Tasks

View all tasks currently in the database in a formatted table.

tsx main.ts list

5. Filter Tasks by Status

View a filtered list of tasks by passing a specific status flag (pending, completed, or deleted).

tsx main.ts list --status=pending

🧠 Technical Highlights

• Singleton Data Pattern: The db.ts file acts as a single source of truth, loading the JSON database into memory once and sharing it across all modular functions via Module Caching.
• Temporal Dead Zone Prevention: File execution is strictly ordered to ensure database arrays are initialized into memory prior to the router firing.
• Type Narrowing & Guard Clauses: Extensive use of early returns and type validation to prevent undefined or NaN inputs from crashing the Node execution thread.
• Explicit Imports: The application bypasses barrel files in favor of explicit, direct imports to maintain strict visibility of dependencies within the main.ts router.