Next JS Typescript: Everything You Need to Know

Combining Next JS and Typescript allows developers to build powerful and scalable web applications that are easy to maintain and evolve. In this article, we will explore the benefits of using Next JS with Typescript and how to get started with this powerful combination.

Next.js is a popular React-based framework that makes it easy to build web applications. It provides many useful features such as server-side rendering, automatic code splitting, and dynamic imports. In addition, Next.js offers excellent developer experience with fast feedback cycles and automatic page routing.

TypeScript is a statically typed superset of JavaScript that brings many benefits to web development, such as improved code quality, better code organization, and early error detection. TypeScript is a popular choice for many developers, and it is widely used in the React community.

Benefits of Using Next.js with TypeScript

Using TypeScript with Next.js brings many benefits to web development, such as:

• Better code quality: TypeScript provides static type checking, which helps catch errors at compile time instead of runtime. This makes it easier to write bug-free and maintainable code.
• Improved code organization: TypeScript allows you to define interfaces and types, which makes it easier to reason about your code and reduces the risk of unexpected behaviour.
• Early error detection: TypeScript provides rich editor support, including code completion, code navigation, and error highlighting, which helps you catch errors early in the development process.

Also Read: How to add Google AdSense in Next JS

Setting up a New Next JS Typescript Project

To set up a Next.js project with TypeScript, you can use the official TypeScript starter template. This template includes all the necessary configuration files and dependencies to get started with the Next.js project. This will help us so much.

To create a new Next.js project with TypeScript, run the following command. nextjs-ts is our project name here.

npx create-next-app --example with-typescript nextjs-ts

Now go to the project folder and run the command npm run dev to start the development server.

Also Read: How to add Next JS Redirect

Writing Type-Safe Components in Next.js

In Next.js, you can write type-safe components using TypeScript. This allows you to define the expected props and their types, which makes it easier to reason about your code and reduces the risk of unexpected behaviour.

To define a type-safe component in Next.js, Create a new file in the components folder, for example MyComponent.tsx and Define the props interface and their types

interface MyComponentProps {
  text: string;
}

const MyComponent: React.FC<MyComponentProps> = ({ text }) => {
  return <div>{text}</div>;
};

export default MyComponent;

In the example above, we defined a MyComponentProps interface with a single property text of type string. We then define the MyComponent function component with the React.FC type, which takes the MyComponentProps as its only parameter. Finally, we export the component for use in other parts of the application.

Also Read: How to use SCSS with Tailwind in Next JS

Using TypeScript with Next.js APIs and Middleware

In Next js, you can also use TypeScript with APIs and middleware. This allows you to define the expected input and output types, which makes it easier to reason about your code and prevent errors.

To use TypeScript with Next.js APIs and middleware, Create a new file in the pages/api folder, for example my-api.ts. Define the input and output types for the API. Here is an example –

interface MyApiRequest {
  query: string;
}

interface MyApiResponse {
  data: any[];
}

In the example above, we define the MyApiRequest interface with a single property query of type string, and the MyApiResponse interface with a single property data of type any[].

Define the API route handler with the expected input and output types, for example:

import { NextApiRequest, NextApiResponse } from 'next';

export default function myApiHandler(
  req: NextApiRequest & MyApiRequest,
  res: NextApiResponse<MyApiResponse>
) {
  const { query } = req.query;

  const data = [
    { id: 1, name: 'John' },
    { id: 2, name: 'Jane' },
  ];

  res.status(200).json({ data });
}

In the example above, we define the myApiHandler function with the expected input and output types. We use the NextApiRequest and NextApiResponse types from Next.js, and extend them with our own MyApiRequest and MyApiResponse types. We then use these types to access the query parameter in the request and return a JSON response with the data property.

Also Read: How to Generate ZIP with File Links in Next JS and React JS

Debugging Next.js and TypeScript Applications

Debugging Next.js and TypeScript applications can be challenging, but there are many tools and techniques available to make it easier.

Here are some tips for debugging:

• Use a debugger: Debugging with a debugger can be much more efficient than using console.log statements. VS Code and other IDEs have built-in debugging tools that work well with Next.js and TypeScript.
• Enable source maps: Source maps allow you to map the compiled TypeScript code to the original source files, which makes it easier to debug your code. Next.js generates source maps by default, but you may need to configure your IDE to use them.
• Check the TypeScript configuration: Make sure your TypeScript configuration is correct and up to date. Errors in the configuration can cause unexpected behaviour or prevent the code from compiling.
• Use the --inspect flag: The --inspect flag allows you to attach a debugger to a running Node.js process. This can be useful for debugging server-side code in Next.js.

Frequently Asked Questions (FAQs)

Conclusion

Using TypeScript with Next.js is a powerful combination that brings many benefits to web development. With TypeScript, you can write more maintainable and bug-free code, and with Next.js, you can build powerful and scalable web applications. In this article, we’ve covered the benefits of using Next.js with TypeScript and how to get started with this powerful combination. With the right tools and techniques,