What happens when a developer executes npm install with incompatible peer dependencies?

When a developer executes npm install with incompatible peer dependencies, the command succeeds but shows a warning about the version mismatch. This behavior is by design in npm to ensure that the process of installing packages remains as unbroken as possible, even if the peer dependencies specified by packages are not satisfied by the current installation.

Peer dependencies are intended to signify that a package is compatible with a certain version of another package. However, if the project has a version that conflicts with the peer dependency requirement, npm doesn't prevent the installation of the package. Instead, it allows the installation to proceed while issuing a warning that notifies the developer about the potential incompatibility. This allows developers to take notice of any issues arising from version mismatches while still being able to continue their work without interruption.

Incompatibilities are highlighted to ensure that developers are aware of potential issues, leaving the choice to update or resolve dependencies to them.