How to use npm command in a repo that uses pnpm

In a repository managed by pnpm for dependency management, the recommended practice is to continue using pnpm for installing, updating, or removing packages to ensure consistency and efficiency. pnpm operates similarly to npm but manages node modules via hard linking, which enhances efficiency and reduces disk space consumption.

However, if you need to use npm in such a repository under certain circumstances, follow these steps:

Step 1: Verify package.json and Lock Files

First, ensure that the package.json file does not include pnpm-specific features such as workspaces, as they may not be supported by npm. Additionally, due to the incompatibility between pnpm-lock.yaml and package-lock.json, you might need to regenerate the lock file.

Step 2: Generate npm Lock File

In the project root directory, run the following command to remove the pnpm lock file and node_modules, then reinstall dependencies with npm to generate the correct package-lock.json:

bash
rm -rf pnpm-lock.yaml node_modules
npm install

This will create a new package-lock.json file and node_modules directory, installing and locking dependencies according to npm's method.

Step 3: Perform Regular npm Operations

At this point, you can use npm commands to manage dependencies, such as installing new packages or updating existing ones:

bash
npm install <package-name>
npm update <package-name>

Important Considerations

1. Dependency Consistency: Switching package managers may lead to dependency inconsistencies, especially in team projects. It is recommended to standardize on a single package manager within the team.
2. Ongoing Maintenance: If you decide to switch to npm, clearly document this in the project documentation to avoid future confusion between the two tools.
3. Performance Implications: pnpm saves disk space and speeds up installations through hard linking, whereas npm may not offer these benefits.

Example

Suppose you encounter a bug in a pnpm-based project that requires temporarily switching to npm to test if it is caused by pnpm's behavior. Following the above steps, you can safely switch to npm, perform testing and development, and ultimately determine the root cause.

In summary, while it is possible to use npm in a pnpm-based project, it may introduce complexity and risks in dependency management. Unless absolutely necessary, it is advisable to continue using the original package manager.