fix: detect changes to the root package in single-package repos

[theoephraim]

Problem

In a single-package (non-monorepo) repo, bumpy ci check always reported "No managed packages have changed — no bump files needed." and never posted a PR comment — even when source files clearly changed.

Reported via a fresh setup in dmno-dev/fledgling (failing run). The repo was not misconfigured.

Root cause

Changed files were matched against the package directory like so:

const pkgRelDir = relative(rootDir, pkg.dir);
if (file.startsWith(pkgRelDir + '/')) { ... }

For the root package of a single-package repo, pkg.dir === rootDir, so pkgRelDir === '' and the test becomes file.startsWith('/') — always false for git's relative paths (src/cli.ts, etc.). The root package therefore never matched any changed file.

In monorepos every package lives under packages/<name>/, so pkgRelDir is non-empty and the bug was masked.

This same pattern appeared in two places:

• findChangedPackages in check.ts — used by check and ci check
• mapFilesToPackages in generate.ts — used by generate to attribute commits to packages

So generate was also failing to attribute any commit to the root package in single-package repos.

Fix

Treat the root package (empty relative dir) as owning every changed file. In findChangedPackages, changedFilePatterns is still honored:

const relToPackage =
  pkgRelDir === ''
    ? file
    : file.startsWith(pkgRelDir + '/')
      ? file.slice(pkgRelDir.length + 1)
      : null;
if (relToPackage !== null && matchers.get(name)!(relToPackage)) {
  changed.add(name);
}

Tests

• findChangedPackages: root-package detection, changedFilePatterns honoring, monorepo directory scoping (regression).
• mapFilesToPackages: root-package detection + monorepo scoping (exported the helper to test it).

Full suite: 314 pass / 0 fail. Lint, fmt, and typecheck clean.

[github-actions]

The changes in this PR will be included in the next version bump.

Patch releases

• @varlock/bumpy 1.14.0 → 1.14.1

Bump files in this PR

• single-package-changed-detection.md (view diff) (edit)

Click here if you want to add another bump file to this PR

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This comment is maintained by bumpy.