TypeScript Best Practices for Vue Applications

TypeScript brings static type checking to JavaScript, making your Vue applications more robust and maintainable. Here are the essential best practices for using TypeScript with Vue.

Setting Up TypeScript with Vue

First, ensure you have TypeScript installed and configured:

npm install -D typescript @vue/typescript

Defining Component Props

Always define proper types for your component props:

interface Props {
  title: string;
  count?: number;
  items: string[];
}

const props = defineProps<Props>();

Typing Reactive Data

Use proper types for reactive references:

interface User {
  id: number;
  name: string;
  email: string;
}

const user = ref<User | null>(null);
const users = ref<User[]>([]);

Computed Properties

Type your computed properties for better IntelliSense:

const fullName = computed((): string => {
  return `${user.value?.firstName} ${user.value?.lastName}`;
});

Event Handlers

Type your event handlers properly:

const handleClick = (event: MouseEvent): void => {
  console.log('Button clicked', event.target);
};

API Responses

Define interfaces for API responses:

interface ApiResponse<T> {
  data: T;
  status: number;
  message: string;
}

const fetchUsers = async (): Promise<ApiResponse<User[]>> => {
  const response = await fetch('/api/users');
  return response.json();
};

Generic Components

Use generics for reusable components:

interface ListProps<T> {
  items: T[];
  keyField: keyof T;
  renderItem: (item: T) => string;
}

const List = <T>(props: ListProps<T>) => {
  // Component implementation
};

Following these TypeScript best practices will make your Vue applications more type-safe, maintainable, and easier to debug. Start with basic typing and gradually adopt more advanced patterns as your application grows.