fix(git): never discard committed local work in rebase_onto_base (#683)

The shared rebase primitive (dev sync_branch verb, PM/CEO rebase path, submit-freshen, merge-conflict resolver) opened with fetch -> checkout -> unconditional reset --hard origin/<head_branch>. The dirty-tree gate protects uncommitted edits only; the reset silently rewound past every committed-but-unpushed commit — and the commit do-verb never pushes, so mid-rework a dev routinely has exactly that. The force-with-lease push then republished the truncated branch as authoritative (the lease matched the freshly-fetched, never-moved origin ref). rebase_onto_base now classifies local vs origin/<head> post-fetch: - behind/equal: reset --hard origin as before (origin loses nothing) - strictly ahead: reset skipped — the rebase runs from the local tip and the lease'd push publishes the previously-doomed commits - diverged: a patch-equivalence probe (rev-list --right-only --cherry-pick) first rescues the self-inflicted residue of a prior rebase whose force-push failed (treated as ahead, self-heals on retry); only genuine two-sided divergence returns a new {status: diverged, local_only, origin_only} — no reset, no rebase, no push, neither side silently discarded - an absent local ref is recovered from origin (branch + checkout, never reset) Callers: the sync_branch verb maps diverged to an actionable envelope steering to i_am_blocked (stash-preserved note included); the submit-freshen hard-rejects it like conflicts; the merge-conflict resolver already escalates any non-rebased/superseded status to the CEO and degrades gracefully (pinned by test, no code change). New real-git suite (bare origin + clone, no subprocess mocking) asserts origin-side outcomes: ahead-publishes, behind-adopts, diverged-refuses-untouched, absent-ref recovery, superseded, conflicts, and wedge self-heal on retry via a rejecting pre-receive hook. Co-authored-by: Renn F <rennf93@users.noreply.github.com>
2026-08-03 07:23:24 +02:00 · 2026-07-24 14:34:25 +02:00
parent 3516d925fe
commit 71f5426e40
9 changed files with 744 additions and 63 deletions
@@ -131,6 +131,73 @@ async def test_sync_branch_conflicts_aborts_and_steers_to_resolve() -> None:
    assert "sync_branch again" in env.next


+@pytest.mark.asyncio
+async def test_sync_branch_diverged_steers_to_i_am_blocked() -> None:
+    """A diverged branch is not an error — it's a clean ok-envelope hint to
+    escalate, mirroring how a conflict is surfaced (git-only op, no DB
+    transition either way)."""
+    aid = uuid4()
+    tid = uuid4()
+    t = _task(tid=tid, aid=aid)
+    task_svc = AsyncMock()
+    task_svc.get.return_value = t
+    task_svc.agent_for.return_value = MagicMock(role="developer", team="backend")
+    git_svc = AsyncMock()
+    git_svc.sync_task_branch.return_value = {
+        "status": "diverged",
+        "local_only": 2,
+        "origin_only": 1,
+    }
+    deps = _make_deps(task=task_svc, git=git_svc)
+    c = Choreographer(deps)
+
+    with patch(
+        "roboco.services.gateway.choreographer._impl.resolve_parent_branch",
+        new=AsyncMock(return_value=_BASE),
+    ):
+        env = await c.sync_branch(aid, tid)
+
+    assert env.error is None
+    assert env.next is not None
+    assert "DIVERGED" in env.next
+    assert "i_am_blocked" in env.next
+
+
+@pytest.mark.asyncio
+async def test_sync_branch_diverged_with_stash_pop_conflict_notes_preserved_stash() -> (
+    None
+):
+    """A diverged result can ALSO carry a stash-pop conflict (the stash was
+    taken, the rebase never touched either side, but popping it back still
+    collided) — the hint must not drop that warning."""
+    aid = uuid4()
+    tid = uuid4()
+    t = _task(tid=tid, aid=aid)
+    task_svc = AsyncMock()
+    task_svc.get.return_value = t
+    task_svc.agent_for.return_value = MagicMock(role="developer", team="backend")
+    git_svc = AsyncMock()
+    git_svc.sync_task_branch.return_value = {
+        "status": "diverged",
+        "local_only": 2,
+        "origin_only": 1,
+        "stash_pop_conflict": True,
+    }
+    deps = _make_deps(task=task_svc, git=git_svc)
+    c = Choreographer(deps)
+
+    with patch(
+        "roboco.services.gateway.choreographer._impl.resolve_parent_branch",
+        new=AsyncMock(return_value=_BASE),
+    ):
+        env = await c.sync_branch(aid, tid, stash=True)
+
+    assert env.error is None
+    assert env.next is not None
+    assert "DIVERGED" in env.next
+    assert "preserved" in env.next.lower()
+
+
@pytest.mark.asyncio
 async def test_sync_branch_not_found_for_unknown_task() -> None:
    aid = uuid4()