# NPM Tricks I Wish I Knew Sooner

Recently I have been working on migrating an old React application based on react-scripts to support Node.js 18. To make it work, I came across multiple npm tricks that helped solve these issues, so I am going to explain and document them in this blog.

### Dependencies Checks

```bash
npx depcheck
```

Analyzes the dependencies in a project to see how each dependency is used, which dependencies are unused, and which dependencies are missing from `package.json`.

### Why Events

```bash
npm why package_name
```

This command helps you understand why a package is installed in your project and where it comes from.

### Check Subdependencies

```bash
npm ls buffer
```

Prints all the versions of packages that are installed, as well as their dependencies.

### Find Duplicates

```bash
npm find-dupes
```

Runs `npm dedupe` and outputs all the duplication changes without changing the package tree.

### Reduce Duplication

```bash
npm dedupe
```

Searches the local packages tree and attempts to simplify the overall structure by moving dependencies further up the tree, where they can be more effectively shared by multiple dependent packages.

### Clean Install

```bash
npm ci
```

If you have already set up projects where you have `node_modules` and `package-lock.json`, using this command will remove them and perform a clean install.

### Resources:

* [https://www.npmjs.com/package/depcheck](https://www.npmjs.com/package/depcheck)
    
* [https://docs.npmjs.com/cli/v11/commands](https://docs.npmjs.com/cli/v11/commands)