Node Version Manager (NVM) is a command-line utility that allows developers to easily manage multiple installations of Node.js on a single machine. Node.js is a popular runtime environment that allows developers to execute JavaScript code server-side, making it a key component for building web applications, APIs, and other server-related tasks. NVM simplifies the process of switching between different versions of Node.js, enabling developers to work with various projects that might require different Node.js versions.

Why Use Node Version Manager (NVM)?

1. Version Compatibility: Different projects may have specific requirements for the version of Node.js they run on. Using NVM, developers can seamlessly switch between these versions without conflicting installations.
2. Stability and Performance: New versions of Node.js often come with performance improvements, bug fixes, and security enhancements. NVM allows developers to update to the latest Long-Term Support (LTS) or current versions to take advantage of these benefits.
3. Project-Specific Isolation: NVM provides project-specific isolation by managing Node.js installations per project directory. This ensures that each project uses its designated Node.js version, avoiding potential compatibility issues.
4. Testing and Development: Developers can use NVM to test their applications on different Node.js versions to ensure cross-version compatibility. This is particularly important when dealing with complex projects that might have dependencies sensitive to Node.js version changes.

Using NVM to Manage Node.js Versions

• Installation: To install NVM, follow the installation instructions provided on the official NVM repository for your operating system.
  • Linux: Installation instructions
  • Windows: Releases – download and run latest nvm-setup.exe.
• Installing Node.js Versions: Once NVM is installed, you can use the nvm install <version> command to install different Node.js versions. For instance, to install Node.js v18, use nvm install 18.
• Switching Between Versions: Use the command nvm use <version> to switch to a specific Node.js version. For example, to switch to Node.js v14, use nvm use 14.
• Default Version: You can set a default Node.js version to be used whenever you open a new terminal window by running nvm alias default <version>.
• Listing Installed Versions: To view a list of installed Node.js versions, type nvm ls.

Project Considerations: Node.js v18 vs. v14

While it’s generally recommended to use the latest LTS version of Node.js (currently v18) due to its improved performance, security, and features, there might be cases where projects are locked into an older version like Node.js v14 due to compatibility constraints. In such situations:

• For New Projects: Whenever possible, start new projects using the latest available LTS version (currently v18) to benefit from the latest enhancements.
• Legacy Projects: For projects that specifically require Node.js v14 due to compatibility reasons, utilize NVM to manage the version and isolate it from other projects.

Using .nvmrc to Specify Node.js Version for a Project

Node Version Manager (NVM) provides options for configuring specific Node.js versions on a per-project basis. This can be achieved using the .nvmrc file within your project’s directory.

1. Create .nvmrc File: In the root directory of your project, create a file named .nvmrc (note the leading dot). Inside this file, simply write the desired Node.js version number. For example, to specify Node.js v14, your .nvmrc file would contain:

# .nvmrc
14

You can also specify a version alias or a version range, depending on your needs. For example:

# .nvmrc
lts/*

This would use the latest LTS version of Node.js.

Automatic Switching: With the .nvmrc file in place, NVM will automatically switch to the specified Node.js version whenever you navigate into the project directory using the cd command. This ensures that you’re using the correct version for that specific project.

Manually Switching: If you want to manually switch to the Node.js version specified in the .nvmrc file, you can simply use the nvm use command without specifying a version:

nvm use

NVM will read the .nvmrc file and switch to the version defined there.

Using the .nvmrc file is a great way to ensure that your projects are using the correct Node.js version without needing to remember or specify the version each time you work on the project. It’s especially useful when collaborating with other developers on the same project to maintain consistency in the development environment.

Remember that the .nvmrc file should only contain the Node.js version number, alias, or range on a single line without any extra characters or comments.