fix: include dotfiles in cache output glob matching

[christiango]

Related previous PRs: https://github.com/microsoft/backfill/pull/551/changes

Problem

Dotfiles and dotfolders (e.g. .vite/, .next/, .env) in build output directories are silently dropped when lage caches task outputs. A fresh build produces these files correctly, but restoring from cache omits them entirely.

This happens because the glob calls that collect output files for caching use the default dot: false option from globby/fast-glob. Patterns like releaseDeployment/**/* or dist/**/* don't match paths containing dot-prefixed segments (e.g. releaseDeployment/public/.vite/manifest.json).

Root Cause

Three glob call sites were missing dot: true:

1. CacheStorage.put() — the glob that matches outputGlob patterns to determine which files to store in cache
2. getHashesFor() — the glob used by incremental caching to enumerate all files for hash comparison
3. getOutputFiles() — the server-mode function that collects output files for the cache-aware runner

LocalCacheStorage._fetch() already used dot: true when reading files back from cach, but since dotfiles were never stored, there was nothing to restore.

Fix

Add dot: true to all three glob call sites:

File	Function	Change
packages/backfill-cache/src/CacheStorage.ts	getHashesFor()	{ cwd, dot: true }
packages/backfill-cache/src/CacheStorage.ts	put()	{ cwd: this.cwd, dot: true }
packages/cli/src/commands/server/getOutputFiles.ts	getOutputFiles()	{ cwd: target.cwd, gitignore: false, dot: true }

Tests

Added 4 new tests across 2 test files — all fail before the fix and pass after:

cacheStorage.test.ts (unit):

• caches dotfiles in subdirectories matched by outputGlob — verifies dist/**/* matches .vite/manifest.json inside dist/public/
• caches dotfiles when outputGlob uses **/* — verifies **/* matches .env at root level

LocalCacheStorage.test.ts (round-trip put/fetch):

• will cache and restore dotfiles inside output directories — full cycle with dist/.vite/manifest.json
• will cache and restore dotfiles when using releaseDeployment/**/* — full cycle matching the exact pattern used by consumers like Loop

How It Was Found

In an internal repo Vite build produces .vite/manifest.json inside releaseDeployment/public/. After running vite the file exists in the right place. But deleting releaseDeployment/ and re-running yarn bundle --to bebop (which restores from lage cache) produces output missing the .vite/ directory. This causes downstream issues since the manifest is needed at runtime.