Array Guard

🛡️ ArrayGuard

ArrayGuard is a lightweight VS Code extension that scans your JavaScript and TypeScript files for unsafe array access patterns, such as missing null checks, risky .length usage, and unguarded array method calls. It helps you catch subtle bugs before they break your application.

✨ Features ArrayGuard detects common risky patterns, including:

🔍 Unsafe array access Using .length without verifying the array exists

Calling array methods like .map(), .filter(), .forEach() without null checks

⚠️ Weak null checks if (!arr)

if (arr == null)

Other loose or incomplete checks

🧠 Diagnostics Highlights issues directly in the editor

Adds warnings to the Problems panel

Shows a summary after each scan

🚀 Usage Run the command:

ArrayGuard: Scan File for Unsafe Array Access

You can trigger it via:

Command Palette → Ctrl+Shift+P → “ArrayGuard”

Keyboard shortcut (if you add one)

Right‑click menu (optional to add later)

ArrayGuard will analyze the active file and report any potential issues.

🛠️ How It Works ArrayGuard uses simple static analysis with pattern matching to detect:

Array property access

Array method calls

Null/undefined checks

Suspicious conditions

It then creates VS Code diagnostics to highlight the risky code.

📁 Example

console.log(items.length); // ⚠️ Warning: unsafe .length access items.map(x => x * 2); // ⚠️ Warning: unsafe array method call

🧩 Requirements No external dependencies. Works with:

JavaScript

TypeScript

🗺️ Roadmap Add Quick Fix suggestions (e.g., auto‑add ?.)

Add support for more languages

Add configuration for custom rules

Add real‑time scanning instead of manual command