How to determine if Node.js process is running in a git directory ?

Node.js is an open-source, cross-platform, back-end JavaScript runtime environment. It allows developers to run JavaScript on the server side, creating server-side applications with JavaScript. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices. It has an extensive library of modules that simplify the development of server-side and networking applications. Node.js is commonly used for web servers, real-time applications, and microservices.

In this article, we are going to see if a Node process is running in a git directory.

What is Git?

Git is a version control system for software development. It allows developers to track changes made to the code and collaborate with others on the same codebase. Git is a command-line tool, but there are also graphical user interface-based programs that allow users to interact with the software in a more user-friendly way. To track changes in a directory git used a hidden folder named .git. The .git folder contains all the metadata that the git tool requires to manage and track changes. 

Approach 1: To determine if a Node.js process is running in a Git directory, we will use the fs module, which is built into Node.js, to check for the presence of a .git directory. We are going to make use of fs.statSync() function to perform the checking. We are going to make use of the following steps:

• Import the fs module at the top of your script.
• Write a function called isGitDirectory that takes no arguments. Inside the function, use fs.statSync to check for the presence of a .git directory.
• If the .git directory exists, the fs.statSync method will return a Stats object that contains information about the directory, including its size, ownership, and permissions. If the .git directory does not exist, the fs.statSync method will throw an error with a code of 'ENOENT'.
• In the isGitDirectory function, you can handle this error by using a try-catch block. If the error code is 'ENOENT', it means the .git directory does not exist, so you can return false. If no error is thrown, it means the .git directory exists, so you can return true.
• Call the isGitDirectory function wherever you need to check whether the current Node process is running in a Git directory. For example, you might call it a conditional statement to determine what code to execute based on whether the process is running in a Git directory or not.

fs.statSync() is a method in the fs module of Node.js that synchronously returns information about the given file or directory. It takes a file or directory path as its only argument and returns an object that contains information such as the file's size, creation, and modification time, and whether it's a directory or a file.

Example: The following program will check if the current directory contains a .git folder or not.

import fs from 'fs';

function isGitDirectory() {
    try {
        fs.statSync('.git');
        return true;
    } catch (err) {
        if (err.code === 'ENOENT') {
            return false;
        }
        throw err;
    }
}

console.log(isGitDirectory());

Output: First we will run the above program in a non-git directory. I am using the following command in my terminal to check if the directory really contains a .git folder or not:

ls -a | grep ".git"

We will get the following output when running on the non-git directory:

Now we will initialize the directory to be a git folder. Rerunning the code gives the following output:

Approach 2: In this approach, we are going to make use of the is-git-repository package. We will start by installing the package. Type the following command to install:

npm i is-git-repository

We are going to make use of the following steps to determine:

• Import the isGitRepository function at the top of your script.
• Call the isGitRepository function wherever you need to check whether the current Node process is running in a Git directory. This function takes a path argument that defaults to the current working directory (process.cwd()), so you can simply call isGitRepository() with no arguments to check the current working directory.
• The isGitRepository function returns a boolean value that indicates whether the specified directory is a Git repository or not. If the directory is a Git repository, the function returns true. If the directory is not a Git repository or if an error occurs, the function returns false.

Example: The following program will check if the current directory contains a .git folder or not.

import isGitRepository from 'is-git-repository';

if (isGitRepository()) {
    console.log('This Node process is running in a Git repository.');
} else {
    console.log('This Node process is not running in a Git repository.');
}

Output: First, we will run the above program in a non-git directory. I am using the following command in my terminal to check if the directory really contains a .git folder or not:

ls -a | grep ".git"

We will get the following output when running on the non-git directory:

Now we will initialize the directory to be a git folder. Rerunning the code gives the following output: