How to Check if File Exists in NodeJS

NodeJS is a powerful JavaScript framework to help you build web applications and website using JavaScript. It provides many functions to work with files. Most often, you may need to check if a file exists in NodeJS. If you try to access a file that does not exist, NodeJS will give an error and your code may stop working. In this article, we will learn how to check if file exists in NodeJS.

How to Check if File Exists in NodeJS

Here are the steps to check if file exists in NodeJS.

NodeJS provides fs module to access file system. Let us say you want to test if the following file path exists.

path = '/home/ubuntu/test.txt'

First, we import this module.

const fs = require("fs");

Now there are two ways to check if a file exists – synchronous way and asynchronous way. We will look at both these methods one by one.

1. Synchronous File Check

In this case, you can easily check if a file exists with the existsSync() function, which returns true if the file path exists and false if the file path does not exist.

if (fs.existsSync(path)) {
    // file exists
}else{
  // file does not exist
}

2. Asynchronous File Check

You can also do an asynchronous check using fs.promises.access or fs.access.

try {
    await fs.promises.access(path);
    // file exists
} catch (error) {
    // file does not exist
}

Alternatively, you can also check it with a callback.

fs.access("somefile", error => {
    if (!error) {
        // file exists
    } else {
        // file does not exist
    }
});

In this article, we have learnt several ways to check if file exists or not in NodeJS. You can use any of them depending on your requirement.

Please note, the fs module is frequently updated and sometimes the functions mentioned above might become deprecated. If you find that to be the case, please let us know in comments and we will update this article immediately.

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