fix(tasks): merge cross-lineage dependency content at branch cut (#466)

* fix(tasks): merge cross-lineage dependency content at branch cut The dependency gate enforced timing but never content: a dependent's fresh branch could miss a same-repo dependency's merged work when that merge landed outside the branch's own ancestor chain (cross-cell edges under one root, same-repo batch cross-root edges). After a successful branch cut, each dependency's real merge target (resolve_parent_branch) is fetched and, unless already an ancestor, merged into the new branch; conflicts abort cleanly (branch stays at its cut point, warning + an accumulating task marker note) and never fail the claim. Cross-repo dependencies are skipped — no shared history. Zero git work for the no-deps common case; resumes never re-enter (branch creation only). * chore(foundation): regenerate lifecycle artifacts; reflow inherited prose * [lineage] mypy-clean mock idioms in the lineage orchestration tests --------- Co-authored-by: Renn F <rennf93@users.noreply.github.com>
2026-08-03 07:23:24 +02:00 · 2026-07-11 09:21:24 +02:00
parent 50ec283533
commit f2834cf521
4 changed files with 651 additions and 0 deletions
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+"""``GitService.merge_dependency_lineage`` — the cross-subtree/cross-cell
+dependency-lineage gap.
+
+The claim-time dependency gate (``TaskService._claim_blocked_by_dependencies``)
+only enforces TIMING — a dependency must be terminal before the dependent task
+can claim — it never checks whether the dependency's MERGED content is
+reachable from the dependent's freshly cut branch. A cross-subtree/cross-cell
+edge (e.g. a UX cell task merged into the UX cell branch, depended on by a
+sibling frontend cell task cut from the frontend cell branch) can complete on
+a branch the dependent never descends from.
+
+This backfills it at branch-cut time: fetch the dependency's merge-target
+branch, no-op if it is already an ancestor of the fresh branch (the common,
+transitively-safe case), otherwise merge it in. On a real conflict the merge
+is aborted and the branch is left exactly at its cut point — a content
+assist, never a gate, so it always returns a status rather than raising.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Any
+from unittest.mock import AsyncMock, MagicMock
+from uuid import uuid4
+
+import pytest
+from roboco.services.git import GitService
+
+_WORKSPACE = Path("/tmp/fake-ws")
+_TASK_ID = uuid4()
+_WORKTREE = _WORKSPACE / ".worktrees" / str(_TASK_ID)[:8]
+_BRANCH = "feature/frontend/root--fe-cell"
+_SOURCE = "feature/ux_ui/root--ux-cell"
+_ORIGIN_SOURCE = f"origin/{_SOURCE}"
+
+
+def _git_service() -> GitService:
+    svc = GitService.__new__(GitService)
+    svc.log = MagicMock()
+    return svc
+
+
+def _result(returncode: int = 0, stdout: str = "") -> Any:
+    r = MagicMock()
+    r.returncode = returncode
+    r.stdout = stdout
+    return r
+
+
+def _drive(
+    svc: GitService, responses: dict[tuple[str, ...], Any]
+) -> list[tuple[Path, list[str]]]:
+    """Stub _run_git to answer by args-prefix; _ensure_worktree_for_commit +
+    _token_for_project are no-ops so only merge mechanics are under test."""
+    calls: list[tuple[Path, list[str]]] = []
+
+    async def _run(workspace: Path, args: list[str], **_kw: object) -> Any:
+        calls.append((Path(workspace), list(args)))
+        for prefix, resp in responses.items():
+            if tuple(args[: len(prefix)]) == prefix:
+                return resp
+        return _result()
+
+    object.__setattr__(svc, "_run_git", _run)
+    object.__setattr__(svc, "_token_for_project", AsyncMock(return_value="tok"))
+    object.__setattr__(svc, "_ensure_worktree_for_commit", AsyncMock())
+    return calls
+
+
+@pytest.mark.asyncio
+async def test_already_ancestor_is_a_no_op() -> None:
+    """source_branch already reachable from branch_name: no merge, no push —
+    the common, transitively-safe case (same-parent siblings, root waves)."""
+    svc = _git_service()
+    calls = _drive(
+        svc,
+        {
+            ("rev-parse", "--verify", "--quiet"): _result(returncode=0),
+            ("merge-base", "--is-ancestor"): _result(returncode=0),
+        },
+    )
+
+    result = await svc.merge_dependency_lineage(
+        _WORKSPACE, _TASK_ID, _BRANCH, _SOURCE, project_slug="roboco-api"
+    )
+
+    assert result == {"status": "already_ancestor"}
+    assert not [c for c in calls if c[1][:1] == ["merge"]], (
+        "an already-ancestor source must never be merged"
+    )
+    assert not [c for c in calls if c[1][:1] == ["push"]]
+
+
+@pytest.mark.asyncio
+async def test_missing_ref_short_circuits_before_touching_worktree() -> None:
+    """source_branch not on origin: no worktree touched, no merge attempted."""
+    svc = _git_service()
+    calls = _drive(svc, {("rev-parse", "--verify", "--quiet"): _result(returncode=1)})
+
+    result = await svc.merge_dependency_lineage(
+        _WORKSPACE, _TASK_ID, _BRANCH, _SOURCE, project_slug="roboco-api"
+    )
+
+    assert result == {"status": "missing_ref"}
+    ensure = object.__getattribute__(svc, "_ensure_worktree_for_commit")
+    ensure.assert_not_awaited()
+    assert not [c for c in calls if c[1][:1] == ["merge-base"]]
+
+
+@pytest.mark.asyncio
+async def test_outside_lineage_merges_and_pushes_from_the_worktree() -> None:
+    """source_branch NOT an ancestor: merged into the worktree and pushed —
+    the actual gap fix (cross-cell dependency content backfilled)."""
+    svc = _git_service()
+    calls = _drive(
+        svc,
+        {
+            ("rev-parse", "--verify", "--quiet"): _result(returncode=0),
+            ("merge-base", "--is-ancestor"): _result(returncode=1),
+            ("merge", "--no-edit"): _result(returncode=0),
+            ("push", "origin"): _result(returncode=0),
+        },
+    )
+
+    result = await svc.merge_dependency_lineage(
+        _WORKSPACE, _TASK_ID, _BRANCH, _SOURCE, project_slug="roboco-api"
+    )
+
+    assert result == {"status": "merged"}
+    merge_calls = [c for c in calls if c[1][:1] == ["merge"]]
+    push_calls = [c for c in calls if c[1][:1] == ["push"]]
+    assert merge_calls and all(ws == _WORKTREE for ws, _ in merge_calls), (
+        "the merge must run in the task's worktree, not the shared clone"
+    )
+    assert push_calls and push_calls[0][1] == ["push", "origin", _BRANCH]
+
+
+@pytest.mark.asyncio
+async def test_merge_conflict_aborts_and_reports_files() -> None:
+    """A real conflict: abort, leave the branch at its cut point, never push."""
+    svc = _git_service()
+    calls = _drive(
+        svc,
+        {
+            ("rev-parse", "--verify", "--quiet"): _result(returncode=0),
+            ("merge-base", "--is-ancestor"): _result(returncode=1),
+            ("merge", "--no-edit"): _result(returncode=1),
+            ("diff", "--name-only", "--diff-filter=U"): _result(
+                stdout="src/a.py\nsrc/b.py\n"
+            ),
+            ("merge", "--abort"): _result(returncode=0),
+        },
+    )
+
+    result = await svc.merge_dependency_lineage(
+        _WORKSPACE, _TASK_ID, _BRANCH, _SOURCE, project_slug="roboco-api"
+    )
+
+    assert result == {"status": "conflict", "files": ["src/a.py", "src/b.py"]}
+    assert not [c for c in calls if c[1][:1] == ["push"]], (
+        "a conflicted merge must never push"
+    )
+    abort_calls = [c for c in calls if c[1] == ["merge", "--abort"]]
+    assert abort_calls, "a failed merge must be aborted, restoring the branch"
+
+
+@pytest.mark.asyncio
+async def test_merge_succeeds_but_push_fails_is_reported_distinctly() -> None:
+    """A clean local merge that can't reach origin is not silently "merged"."""
+    svc = _git_service()
+    _drive(
+        svc,
+        {
+            ("rev-parse", "--verify", "--quiet"): _result(returncode=0),
+            ("merge-base", "--is-ancestor"): _result(returncode=1),
+            ("merge", "--no-edit"): _result(returncode=0),
+            ("push", "origin"): _result(returncode=1),
+        },
+    )
+
+    result = await svc.merge_dependency_lineage(
+        _WORKSPACE, _TASK_ID, _BRANCH, _SOURCE, project_slug="roboco-api"
+    )
+
+    assert result == {"status": "merged_push_failed"}