Nuxt 4 codemon does absolutely nothing - `No changes were made during the codemod run.`

[martinszeltins]

Environment

---

• Operating System: Ubuntu 20.04.4 LTS
• Node Version: v18.12.1
• Nuxt Version: -
• CLI Version: 3.12.0
• Nitro Version: -
• Package Manager: unknown
• Builder: -
• User Config: -
• Runtime Modules: -
• Build Modules: -

---

Reproduction

https://github.com/martinszeltins/nuxt-4-codemon

Describe the bug

I wanted to run the automated Nuxt 4 migration codemon and expected it to move everything to the new directory structure but it just showed this:

No changes were made during the codemod run.

$ npx codemod@latest nuxt/4/migration-recipe

✔ Successfully fetched "nuxt/4/migration-recipe" from local cache.
? Press Enter to run the selected codemods in order.
   You can deselect anything you don’t want. (Press <space> to select, <a> to toggle all, and <enter> to proceed)

❯ ◉ nuxt/4/absolute-watch-path
  ◉ nuxt/4/default-data-error-value
  ◉ nuxt/4/deprecated-dedupe-value
  ◉ nuxt/4/file-structure
  ◉ nuxt/4/shallow-function-reactivity
  ◉ nuxt/4/template-compilation-changes

Running all codemons...
No changes were made during the codemod run.

[mohab-sameh]

Hi @martinszeltins thanks for reporting this.

I checked your sample nuxt-4-codemon-master repo and ran the nuxt/4/absolute-watch-path codemod. The codemod didn’t make any changes because your project doesn’t contain any code that registers a handler for the builder:watch hook (e.g., nuxt.hook("builder:watch", ...)).

This codemod is specifically designed to update code that listens to the builder:watch hook, making sure the path argument is absolute. If your project doesn’t use this hook, the codemod will not make any changes, which is the expected behavior.

If you believe there’s a pattern in your codebase that should have been updated but wasn’t, please point to the specific file and code snippet, and I’ll be happy to investigate further.

[martinszeltins]

@mohab-sameh sorry, no idea what this means tbh, I just wanted it to migrate my app to the new Nuxt 4 structure 😅 I know that Nuxt 4 introduces a new directory structure, so I expected it to move everything under app/. I can do it manually of course, I just don't understand what builder:watch hook means or does 🤷🏻‍♂️

[mohab-sameh]

@martinszeltins I misread a part of the error log and thought you ran nuxt/4/absolute-watch-path only. Seems that your issue is related more to nuxt/4/file-structure.

I'll investigate this soon and update you. But to provide you with a preliminary answer, this happens when the intended 'before' code pattern is not detected. This can be due to either a bug in the codemod (missing an edge case), or your code not actually using the intended before structure.

Keep in mind that codemods are not exhaustive of all use cases and will often have some specific edge cases that won't be handled due to technical limitations and/or missed edge cases.

[martinszeltins]

@mohab-sameh Thanks, I really appreciate you looking into this. 🙏🏻

[TheDutchCoder]

I also encountered the same thing. We use the src dir as the root, and the codemod made no changes at all.