Handling basic errors in Next.js

The Nextjs framework is no exception from other frameworks in terms of errors, and errors, just like bugs, can be stressful and tiring. In this article, we will go over a few common errors in Nextjs.

1. The first error you might encounter might be due to the manual installation of Next.js, and you get a "404 error," this is just because you haven’t created any directories and program files. Because the manual installation only installs the react dependency, you have to add some scripts from the Nextjs website check here into your package.json file. Then you need to create your "pages" directory in your project directory and create a .js file in it and this should solve the issue.. ta-da!

2. So the second one is Syntax error and this is mostly due to mistakes in the JavaScript syntax you wrote in your code, from wrong function declarations to as little as adding extra spaces in variables names in your code, and many more. Here's an example;

/*this will give an error because of the missing parenthesis */
function myFunction(parameter) {
    console.log(parameter);
} 
/*the correct way*/
function myFunction(parameter {
    console.log(parameter);
}

3. Missing dependencies can cause errors in Nextjs. For example, if you didn’t install the required package necessary for a particular function this might cause errors, and you can do this to solve that;

npm install packageName --save

4. Incorrect API routes can also lead to errors. For example, if your URL path is not correctly defined or even if it has incorrect spelling, such as by defining an API route app/userss instead of app/users, you will get a 404 error.

5. Server-side rendering errors in Next.js can occur when a component is not optimized for server-side rendering. For example, if you use the useState hook in a component that is rendered on the server, you will get an error. To fix the error, you should use the useState and useEffect hooks with the no-ssr component:

/* when not optimized for server-side rendering*/
import React, { useState } from 'react';

function Counter() {
  const [count, setCount] = useState(0);

  const handleIncrement = () => {
    setCount(count + 1);
  };

  return (
    <div>
      <h1>Counter: {count}</h1>
      <button onClick={handleIncrement}>Increment</button>
    </div>
  );
}

export default Counter;

/* when optimized for server-side rendering*/
import React, { useState } from 'react';
import dynamic from 'next/dynamic';

const DynamicCounter = dynamic(() => import('./Counter'), { ssr: false });

function MyPage() {
  return (
    <div>
      <h1>My Page</h1>
      <DynamicCounter />
    </div>
  );
}

export default MyPage;

6. Incorrect configuration occurs when the configuration file is not defined correctly. For example, if you define the wrong port in the configuration file, you will get an error when you try to run the application. To fix the error, you can define the correct port in the configuration file:

/*correct configuration*/ 
module.exports = {
  port: 3000,
  /*other configuration settings*/ 
};

7. When the files are improperly arranged, the file structure is incorrect. For instance, if a component is in the wrong directory, using it will result in an error. You can split the files into directories for components, pages, and styles to correct the issue:

// correct file structure
├── components
│   └── my-component.js
├── pages
│   ├── index.js
│