NPM Dependency error

Making a quick post to remind myself in the future how to read these npm dependency errors.

Kudos to this stack overflow post: https://stackoverflow.com/questions/76039613/how-do-i-read-npm-dependency-conflict-errors

Here is my error with two key parts highlighted:

This is stating "for client@1.0.0 I have installed react 18.3.0 BUT react-dom@19.0.0 requires react 19.0.0."

Ok, so how do we resolve this? First of all, we need to make sure we understand the npm versioning scheme with the package.json file.

First step is to understand the semantic versioning system used by npm. A major version 5, minor version 10, and patch version 3 would be 5.10.3, or:

Semantic versioning = MAJOR.MINOR.PATCH

From this article https://flaviocopes.com/npm-semantic-versioning/ we get the following key points for how npm interprets what libraries and versions to install from your package.json file:

• > any version higher than your current version
• ^ - allows updating minor and patch releases. Ex: ^5.1.3. allows updating 5.10.3, but will not allow going to major release 6.
• ~ allows only patch releases

Simplified version of my package.json file

{
"dependencies" : {
  "react": "^18.3.1"
  "@types/react-dom": "^18.2.21",
  }
}

So the first problem here you see with my package.json file is that there is a new major release out now for react which is major version 19. My "^" in my package.json will not allow that to be installed.

To make sure I understood all the new versions I might need to consider in my dependencies I ran the following command

npm outdated

To fix my issues, i updated my package.json file to allow all minor and patch versions of react and react-dom in major version 19:

{
"dependencies" : {
  "react": "^19.0.0"
  "@types/react-dom": "^19.0.0",
  }
}

Also before running the handy npm i command to fix all of this, I deleted my node_modules and package-lock.json folder. I'm pretty sure this isn't necessary now with npm improvements made over time. Never hurts to do this when debugging though since both node_modules and package-lock.json get recreated on the install command.

Now my issues are resolved! Hope this helps.