fix: skip postinstall git clean when not in a git repository

[angeldeejay]

What does this PR accomplish?

The postinstall script runs git clean -df fonts vendor modules/default
unconditionally. When magicmirror is installed as an npm dependency
(e.g. npm install magicmirror or as a transitive dep in another project),
npm runs postinstall in a directory that is not a git repository.
This causes:

fatal: not a git repository (or any of the parent directories): .git

npm treats the non-zero exit as a failure → the entire installation aborts
with code 128. This makes it impossible to use magicmirror as an npm
dependency in any third-party project.

The issue has been present since at least v2.34.0. In v2.35.0
modules/default was added to the clean targets, but the root cause
predates that change.

Fix

Added scripts/postinstall.js — a cross-platform Node.js script that
guards the git clean call with a git rev-parse --git-dir check.

• When running inside a real git repository: behaviour is identical to before.
• When running outside one (e.g. installed as an npm package): step is silently skipped.

package.json postinstall updated from the bare git clean call to:

"postinstall": "node scripts/postinstall.js"

This approach is cross-platform (Linux, macOS, Windows) and keeps the
logic readable rather than inlined as a one-liner.

Does this solve a related issue?

No existing issue tracked. Discovered while using magicmirror as a
devDependency in a companion tooling project — installation failed
unconditionally on all platforms.

Checklist

• Targets the develop branch
• No visual changes (script + package.json only)
• node --run lint:prettier run — no changes needed for .js script

[angeldeejay]

@KristjanESPERANTO can you take a look on this please? I've found this issue while developing MagicMirror sandbox

[KristjanESPERANTO]

Looks good to me. But I'm not the only maintainer 🙂

@khassel, what do you think? Maybe we should take this opportunity to add a note to the script explaining that this is necessary for migrating from an older systems (<2.35.0) to a newer one, and that we can remove it in a few years. We wouldn't have been able to include a comment like that in package.json.

[khassel]

As far as I'm concerned, it can be merged. Another option would be to remove the postinstall command entirely.

Its sole purpose is to remove folders whose contents have been moved and which would otherwise appear in git status.

For installations that haven't been migrated yet, that's just how it is; the user will have to clean it up themselves.

[sdetweil]

I will update the update script to remove the old default module folder

[khassel]

I will update the update script to remove the old default module folder

with this I think the best choice is to remove the postinstall command entirely.

@angeldeejay could you please update this PR accordingly? Thanks and sorry for the inconvenience...

[angeldeejay]

@khassel done!

[angeldeejay]

@khassel @KristjanESPERANTO Do you want me to drop lock files changes and leave only package.json ones?

[angeldeejay]

Assumed yes. I'm guessing your pipelines update lock files by themselves