Why I Switched to TypeScript (And You Should Too)

JavaScript is a dynamic, loosely typed language. This flexibility is what made it popular, but it's also its biggest downfall in large-scale applications. TypeScript adds static typing to JavaScript, and for many, there is no going back.

The Problem with "Vanilla" JS

Imagine a function calculateTotal(price, tax). In JS, nothing stops you from passing "100" (a string) and undefined. You won't find out until runtime when your user sees NaN on their checkout screen.

TypeScript's Value Proposition

1. Static Analysis

TypeScript catches errors compile time (while you write code), not at runtime. It would immediately flag the simplified example above: "Argument of type 'string' is not assignable to parameter of type 'number'."

2. Intelligent Refactoring

Renaming a function used in 50 different files is a nightmare in JS. In TS, the IDE knows exactly where that specific symbol is referenced, allowing for safe, one-click refactoring.

3. Self-Documenting Code

You no longer need to guess the shape of an object API response. Interfaces serve as live documentation.

  interface User {
    id: string;
    email: string;
    role: 'admin' | 'user';
    preferences?: UserPreferences;
  }
        

The Migration Strategy

Migrating isn't all-or-nothing. You can allow JS and TS to coexist.

1. Turn on allowJs: In your tsconfig.json.
2. Migrate Leaf Nodes First: Start with utility functions and simple components that don't depend on others.
3. Use any sparingly: It's tempting to fix errors with any, but try to use unknown or define basic types to maintain safety.

The initial slowdown in velocity pays for itself tenfold in maintenance and bug prevention down the line.