A

Slice 108 - Filesystem Listing Boundaries

Scope#

Split filesystem directory listing internals while preserving FilesystemSourceRuntimeAdapter behavior.

Why Now#

After slice 107, integrations/sources/filesystem/listing.py is the largest production module. It owns directory document assembly, default ignore rules, configured root ignore handling, .gitignore loading, Python directory walking, Git ls-files integration, Git status parsing, Git repo-root probing, and subprocess failure tolerance.

Cosmic Python chapter 04 separates orchestration from interfacing code, and chapter 13 keeps concrete dependency wiring explicit. Applied here: listing.py should assemble the directory document and choose Git-vs-walk source policy, while Git command mechanics, ignore specs, and filesystem walks live in named modules.

In Scope#

  • Move ignore defaults and .gitignore handling to integrations/sources/filesystem/ignore.py.
  • Move Python directory walking to walk.py.
  • Move Git directory listing, status parsing, repo-root probing, and Git command tolerance to git.py.
  • Keep listing.py as the directory document assembly facade.
  • Add an architecture guard that keeps Git command/status parsing, pathspec, and recursive walking out of listing.py.

Out of Scope#

  • Source selection policy changes.
  • New ignore patterns.
  • New source kinds or candidate concepts.
  • Changes to rendered filesystem runtime text.

Verification#

  • Focused filesystem runtime tests.
  • Focused directory selection tests.
  • Architecture guard for filesystem listing boundaries.
  • Service-level filesystem directory runtime dogfood.
  • Full pytest, Ruff, and diff hygiene.