TypeScript Support and Compatibility

Creating next app with TypeScript support

You can create a TypeScript project with create-next-app using the below tags:

•  --ts
•  --typescript 

Syntax:

npx create-next-app@latest --ts

Or, if using yarn:

yarn create next-app --typescript

Adding TypeScript support to Existing project

To add TypeScript support in an existing project, create an empty tsconfig.json file in the root directory:

touch tsconfig.json

Next run, npm run dev or yarn dev. Next.js will guide you via the installation of the required packages to finish the setup run:

npm run dev

You will see instructions like this:

Please install TypeScript, @types/react, and @types/node by running:
    yarn add --dev typescript @types/react @types/node
...

Install the discrepancies as it says.

It will create a file named next-env.d.ts at the root of your project. This file ensures the TypeScript compiler picks up Next.js types. You cannot remove or edit it as it can change with time.

Testing your Next.js app

Begin testing by locating the root of the project and running the command:

npm run dev

or

yarn dev

If everything works okay, you should see your Next app at http://localhost:3000/.

Output:

How TypeScript a blessing for large projects

TypeScript inherits major JavaScript pros and offers additional benefits from static typing and other concepts specific to TS. They prove especially useful for large codebase and distributed teams working on a project.

Optional static typing

JavaScript is a dynamically typed language that checks the types, and datatype errors are spotted only at the runtime. Runtime type checking offers more flexibility, enabling program components to adapt and change on the fly. But the more extensive the project and the team, the more undefined variables are added and the more potential mistakes the code accumulates.

TypeScript introduces optional robust static typing with a balance between flexibility and correctness. A variable doesn’t change its type on declaration and can take only specific values. The compiler warns developers of type-related mistakes, so they have no chance to hit the production phase. The result is less error-prone code and better performance during execution.

It gives the code more structure, makes it self-documenting more readable, speeds up debugging & refactoring, and increases productivity across a large team.

Early bugs spotting

Researchers found that TypeScript detects 15% of common bugs at the compilation stage. This amount is sufficient to save developers time and focus on correcting logic mistakes rather than catching common bugs.

Predictability

In TypeScript, everything stays the way it was initially defined. If a variable has been declared an int, it will always be an int and won’t turn into a Float. Using this enhances the possibility of functions working as originally intended.

Readability

A code that speaks for itself can compensate for the lack of direct communication between team members. Adding strict types and other components that make the code more self-explanatory or adding syntactic sugaring, you can see the design plan of developers who initially wrote the code. It’s vital for distributed teams working on the same project. 

Rich IDE support

Knowledge about types makes editors and Integrated development environments (IDE) valuable. They can offer features like code navigation, autocompletion, and IntelliSense. You also get feedback on your code and error messages as soon as they appear. This support helps you write maintainable code and significantly extends your productivity.

Fast refactoring

Refactoring the app without changing its behavior is needed to keep the codebase robust and maintainable. With TypeScript support, this critical process is less painful. With IDEs knowing much about the code, you can use navigation tools for workflow.

Besides, many mistakes are spotted automatically. TS also simplifies and accelerates refactoring. For example, TS will alert you to the issue if you rename a function and forget to change the name somewhere.

Power of OOP

The TypeScript supports class-based object-oriented programming (OOP) concepts like classes, interfaces, inheritance, etc. The OOP paradigm enables building a well-organized scalable code, and this benefit becomes more evident as your project becomes more extensive and complex.

Cross-platform & cross-browser compatibility

Every gadget, platform, or browser that runs JavaScript supports TypeScript after the compiler translates it into vanilla JS. Usually, IDEs and editors supporting TypeScript have a built-in TS compiler (TSC) invoked from the command line. TypeScript allows converting a part of the codebase or the whole app by adding the tsconfig.json configuration file to the root directory.

Support from the tech world

TypeScript is an open-source language whose community is growing steadily. Loved by millions of developers and supported by Microsoft, conveying confidence that modernizing won’t abandon the technology. You can always seek & get aid from the vast TypeScript community.

Compatibility with Typescript

Next.js has excellent support for TypeScript and is very easy to set up. These two make it simple to build strongly typed React applications with Next.js and TypeScript that run on either client or server side. Frankly,  Next.js and TypeScript is a very compelling stack to try on your next React project.

Frequently Asked Questions

1. What is Next.js?

Next.js is an open-source development framework made on top of Node.js, allowing React-based web application functionalities such as server-side generating and rendering static websites.

2. What are the benefits of using Next.js?

Next.js comes with numerous features that translate into benefits for business and marketing and the development process. The most meaningful thing that developers love is reusable components. As for business, it cuts the development costs. As for developers, it cuts the development time.

3. What is TypeScript?

TypeScript language is a superset of JavaScript, supporting object-oriented programming features like classes, interfaces, polymorphism, Data-binding, data hiding, etc. JavaScript ES5 or earlier versions did not support classes.

4. Is Next JS frontend or backend?

Next.JS is a frontend framework in that it is ReactJS, React-DOM with a NextJS development server for server-side rendering. As such, it is not expected for browser-based JavaScript to be necessary.

5. How to use TypeScript in a browser?

Running TypeScript in a browser needs to be transpired into JavaScript with the TypeScript compiler (TSC). The TSC creates a new .js file based on the .ts file code, which you can use in any way you could use a JavaScript file. 

Key Takeaways

This article teaches about TypeScript Support and compatibility with Next.js. We saw why TypeScript Support could be beneficial for a developer to learn. Click here to see other related blogs on Next.js & Typescript.

Check out our Web development course and blogs on Frontend Web Technologies.

Read out the differences between Typescript vs. Javascript here.

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Happy Learning!