Don't Use npm init on an Existing Project

npm init is a nice tool for initializing a package.json. Today I learned that you should not use it on an existing JavaScript project!

This blog is a Go project, but I use JavaScript dependencies for development. My manifest looks like this:

// package.json
{
  "scripts": {
    "test:e2e": "cypress run",
    "push": "npm run test:e2e && git push"
  },
  "devDependencies": {
    "cypress": "^15.20.1",
    "prettier": "^3.8.3"
  },
  "allowScripts": {
    "cypress@15.20.1": true
  }
}

I thought I could get away with running npm init on it to standardize the file. When I did, the program looked in my node_modules directory and saw ~170 dependencies, most belonging to Cypress.

It then said: “These are dependencies that this project needs, that aren’t listed, so I’ll add them to the manifest.” My project’s dependencies then grew by ~170 😵‍💫.

npm init is for new projects only.

See npm help init for more.