Beagle SCM

JS-051: bin/post.js + decide/commit/conflict — the commit-maker

be post as JS: classify the staged change-set into keep/unlink/add decisions, build the git tree + commit object, write a keeper pack-log (+ idx), FF-advance the ref, append the post row + restamp the files. FF-or-refuse — NO rebase/merge. ← JS-047+JS-048. Part of JS-046. Method: Issues.

Input

Context

• Native sniff/POST.c: 5-way merge → decisions (post_classify_step :440), bottom-up tree build (post_build_tree :789), commit body (tree/parent/author, git-strict order), pack feed (:2929), REFS CAS (REFSCompareAndAppend), post row + file restamp (:3228). Conflict pre-scan before any write (POST-017).
• Pack WRITE is dog/git: git.pack.book/feed/finish (bound); idx via ingest.js::buildIndex (pure JS, transfers whole).

Goals

• bin/lib/decide.js: keep/unlink/add per path (extend classify.js's merge); bin/lib/commit.js: tree+commit framing + pack-write + idx; conflict.js: the WEAVE-marker scan. bin/post.js: orchestrate, FF-or-refuse, the post: banner.

Constraints

• libabc+libdog ONLY; NO keeper/graf binding. We do NOT touch PATCH: THROW where native rebases/merges — non-FF advance (POSTNOFF), absorbed-patch "theirs" trees, and the descendant cascade are out of scope (error, don't handle).
• All refuse-capable checks (conflict, empty-commit, FF) BEFORE opening the pack (POST-017) — no orphan packs / half-written idx.

WIP

Design decisions

• Decisions reuse classify's wtScan/baseline-load; the "theirs" 5th input is absent (no patch) → a present patch row throws (out of scope).
• REFS advance = JS CAS (resolve expected-old, conditional append); non-FF→refuse.
• Commit header order is git-grammar-strict (parent before author; foster/picked after committer) — byte-exact or git fsck rejects the object.

TODOs

• Repro-first parity test/js/post/*: be put ./f && be post '#msg' → JS post vs native: identical commit sha, REFS row, wtlog row, banner; empty-commit POSTNONE; non-FF POSTNOFF (throws, no store write). (Now be/test/post/*, 10 cases incl. agree/refuse/conflict/move/slots.)
• Implement decide.js + commit.js + conflict.js + post.js. (032debec; landed as fold-decide.js/fold-commit.js + shared/conflict.js.)

Blockers and bummers

• ← JS-047 (setMtime) + JS-048 (writers) — both landed 2026-06-22.

Outcome

• LANDED 032debec (bin/post.js + decide/commit/conflict, FF-or-refuse). Today at be/verbs/post/{post,fold-decide,fold-commit}.js + be/shared/conflict.js (beagle-ext shard); parity suite be/test/post/*.
• Scope since grew past FF-or-refuse (patch-absorb: be/test/post/patch-absorb, patch-pat) under later tickets; writePack pairs every pack with an idx run via ingest.buildIndex (fold-commit.js:192) — its run-name collision is JS-099. Audited 2026-07-07.