fix: skip sub-directories when copying a plugin directory

[arpitjain099]

While reading the plugin install path I noticed that internal/file.CopyDirToDir doesn't behave the way its comment describes. It's meant to copy only the top-level regular files of a directory, but the skip-subdirectories guard never fires.

The WalkDir callback names its path parameter path, so the check d.Name() != filepath.Base(path) compares the current entry's base name against itself and is always false. The walk therefore descends into every sub-directory and copies nested files, flattening them into the destination. parsePluginFromDir in the same package gets this right by comparing against the walk root, so the two disagree on what a plugin directory contains: Install validates the top level but then copies nested files too.

The fix compares the walked path against the source root, matching the existing parsePluginFromDir pattern. I added a regression test that fails before the change (a nested file gets copied) and passes after. Verified with go test ./internal/file/... ./plugin/... on linux/amd64.

Thanks for taking a look.

[Copilot]

Pull request overview

This PR fixes internal/file.CopyDirToDir so it truly copies only the top-level regular files of a directory by preventing filepath.WalkDir from descending into subdirectories. It also adds a regression test to ensure nested files in subdirectories are not copied during plugin installation.

Changes:

• Fix subdirectory skipping logic in CopyDirToDir by comparing walked paths against the walk root (src).
• Add a regression test verifying only top-level regular files are copied and that non-directory sources return ErrNotDirectory.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
internal/file/file.go	Corrects the WalkDir callback logic so subdirectories are properly skipped when copying.
internal/file/file_test.go	Adds a regression test to prevent nested files from being copied and validates non-directory error behavior.

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[github-actions]

This PR is stale because it has been opened for 45 days with no activity. Remove stale label or comment. Otherwise, it will be closed in 30 days.

[arpitjain099]

Commenting to keep this off the stale path, and to say the change is still current.

Re-checked main today: internal/file/file.go:94 is unchanged.

// skip sub-directories
if d.IsDir() && d.Name() != filepath.Base(path) {
    return fs.SkipDir
}

path is the callback's own parameter, so d.Name() and filepath.Base(path) are the same string for every entry and the guard never fires. CopyDirToDir therefore walks into sub-directories and flattens nested files into the destination, which is the opposite of what its doc comment says, and it disagrees with parsePluginFromDir in the same package about what a plugin directory contains.

The branch is rebased and mergeable, CI is green, and the diff is two files: the one-line comparison against the walk root, matching the parsePluginFromDir pattern, plus a regression test that fails without it.

No rush from my side, but a look from anyone on the review list would be appreciated, or tell me what you would like changed and I will turn it around.