I had an error caused by the react-refresh library. It seemed some of my packages had dependencies in their packages that depended on different versions of the same dependencies. I used the “npm dedupe” command to solve the problem.
The npm dedupe command removes duplicates in the project’s dependency tree.
When I updated the project with the changes from the remote GitHub repository, to find that I had breaking changes due to my packages. After a couple of hours of reading articles, trying this and that, and unsuccessful debugging. I reached out to a friend for help. He explained that the error was due to the package dependencies, which gave me insight into the problem and exposed the npm dedupe command. I had never used this command before. It left me wandering.
What is npm dedupe?
What does it do anyway?.
Digging around, I found that the npm dedupe analyses the dependency tree and attempts to optimize it by deduplicating dependencies. It does this by moving dependencies higher up in the tree to ensure that only a single version of a particular dependency is used and maintained throughout the project.
Why and when should we use npm dedupe?
I will start with the why.
As we solve problems, we find implementations of some of the features we want to solve existing as libraries, packages, or modules. We use libraries to speed up our development. These libraries and modules become the project dependencies. The project cannot run without them. As we install packages and dependencies, we find that some packages have dependencies. Therefore, more likely to find packages that have the same dependencies.
The when.
Take a scenario where we have the same dependencies in our dependencies at the project level that also have dependencies existing in different versions. For example, module M depends on version 0.1.2 of dependency D, and module M1 depends on version 0.1.3 of the same dependency D. We are most likely to face errors due to our dependencies. In this case, running npm dedupe will update the version of D to 0.1.3. And this will avoid some of the secondary dependencies.