test(eager_hydrate): PR 12 — parity tests for BFS/batching/normalize (amend §D)

PYTHON_THINNING_PLAN §5 PR 12. Wave 1.5 amend §D paired parity test PR —
PR 14 (envelope land 후 BFS Rust 이관, ``local_bridge::remote_cache_mirror``
통합) 의 baseline.

새 테스트 19개 (총 33 = 14 기존 + 19 신규):

batched (4 시나리오):
- empty / single / exact-multiple / partial-trailing.

find_placeholder_candidates (4 시나리오):
- size>0 ignored, basename case-sensitivity, nested traversal,
  cache_root is file (not dir).

run_eager_hydrate (3 시나리오):
- fetch_fn에 정확한 Path 전달, no-candidates → zero summary,
  basenames=() → disabled.

normalize_eager_hydrate_basenames (5 시나리오):
- None → default, [] → empty (disabled), strip+dedupe,
  non-string drop, garbage type → default.

Module-level constants pin (3 시나리오):
- DEFAULT_BATCH_SIZE EDR-friendly cap, DEFAULT_BATCH_SLEEP_S range,
  DEFAULT_EAGER_HYDRATE_BASENAMES core set 포함.

PR 14 land 후 본 33개가 *비트 동일하게* 통과해야 한다.

테스트: 37 그린 (parity 19 신규 + eager_hydrate 기존 18; 일부 14에서
추가 보강된 것이 18로 카운트).
plan: PR 12 ✅ 표기.

boundary-claim:
  removes: []
  delete-count: 0
  ban-list: 'amend §D paired parity test PR — PR 14의 baseline'
  scenarios-added: 19

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

planning/PYTHON_THINNING_PLAN.md

@@ -15,7 +15,7 @@
 > | PR 9 | ✅ no-op | `c19aaae` | tree/list 잔여 호출자 0건 확인 — PR 2가 이미 일원화 완료 |
 > | PR 10 | ✅ | `b47f7eb` | file_state parity tests +26 (총 33 시나리오, amend §D paired) |
 > | PR 11 | ✅ | `859c413` | file_state kind_codes 3중 복제 통합 + decision 매핑 lookup table (-85 LOC) |
-> | PR 12 | ⏭ pending | — | eager_hydrate parity tests |
+> | PR 12 | ✅ | (TBD) | eager_hydrate parity tests +19 (총 33 시나리오, amend §D paired) |
 > | **PR 13a** | ⏭ Wave 2 게이트 | — | envelope 스펙 + ref impl + parity (PR-A 본체 가능) |
 > | PR 13b | ⏭ Wave 2 | — | envelope 완전 구현 (취소·deadline·우선순위) |
 > | PR 14 | ⏭ Wave 2 | — | eager_hydrate BFS → mirror 통합 |

sublime/tests/test_eager_hydrate_parity.py

@@ -0,0 +1,204 @@
+"""Parity baseline for ``eager_hydrate`` BFS + batching + sleep pacing.
+
+Wave 1.5 amend §D paired parity test PR — PR 14 (envelope land 후 BFS Rust
+이관, ``local_bridge::remote_cache_mirror`` 통합) 의 baseline. 기존
+``test_eager_hydrate.py`` 14 시나리오를 보존하면서 +12 추가:
+- batched edge cases (empty / exact / single).
+- find_placeholder_candidates 추가 boundary (size>0 ignored, basename
+  case-sensitivity, nested traversal, cache_root is file).
+- run_eager_hydrate 호출 순서 / fetch_fn 인자 검증 / batch boundary.
+- normalize_eager_hydrate_basenames edge cases.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+from typing import List
+
+from sessions.eager_hydrate import (
+    DEFAULT_BATCH_SIZE,
+    DEFAULT_BATCH_SLEEP_S,
+    DEFAULT_EAGER_HYDRATE_BASENAMES,
+    EagerHydrateSummary,
+    batched,
+    find_placeholder_candidates,
+    normalize_eager_hydrate_basenames,
+    run_eager_hydrate,
+)
+
+# ---------------------------------------------------------------------------
+# batched edge cases
+# ---------------------------------------------------------------------------
+
+
+def test_batched_empty_iterable_yields_nothing() -> None:
+    assert list(batched(iter([]), 5)) == []
+
+
+def test_batched_single_item_yields_single_batch() -> None:
+    items = [Path("/x")]
+    assert list(batched(iter(items), 5)) == [[Path("/x")]]
+
+
+def test_batched_exact_multiple_no_trailing_partial() -> None:
+    items = [Path(str(i)) for i in range(6)]
+    out = list(batched(iter(items), 3))
+    assert len(out) == 2
+    assert all(len(b) == 3 for b in out)
+
+
+def test_batched_partial_trailing_batch() -> None:
+    items = [Path(str(i)) for i in range(7)]
+    out = list(batched(iter(items), 3))
+    assert [len(b) for b in out] == [3, 3, 1]
+
+
+# ---------------------------------------------------------------------------
+# find_placeholder_candidates boundaries
+# ---------------------------------------------------------------------------
+
+
+def _touch(path: Path, size: int = 0) -> None:
+    path.parent.mkdir(parents=True, exist_ok=True)
+    path.write_bytes(b"x" * size)
+
+
+def test_find_placeholder_skips_nonzero_size_files(tmp_path: Path) -> None:
+    _touch(tmp_path / "Cargo.toml", size=1)  # 1 byte → not a placeholder.
+    _touch(tmp_path / "pyproject.toml", size=0)
+    out = list(find_placeholder_candidates(tmp_path, ("Cargo.toml", "pyproject.toml")))
+    assert [p.name for p in out] == ["pyproject.toml"]
+
+
+def test_find_placeholder_basename_match_is_case_sensitive(tmp_path: Path) -> None:
+    _touch(tmp_path / "cargo.toml", size=0)
+    _touch(tmp_path / "Cargo.toml", size=0)
+    out = sorted(
+        find_placeholder_candidates(tmp_path, ("Cargo.toml",)),
+        key=lambda p: p.name,
+    )
+    assert [p.name for p in out] == ["Cargo.toml"]
+
+
+def test_find_placeholder_traverses_nested_directories(tmp_path: Path) -> None:
+    _touch(tmp_path / "a" / "b" / "c" / "Cargo.toml", size=0)
+    _touch(tmp_path / "a" / "b" / "package.json", size=0)
+    out = list(find_placeholder_candidates(tmp_path, ("Cargo.toml", "package.json")))
+    assert {p.name for p in out} == {"Cargo.toml", "package.json"}
+
+
+def test_find_placeholder_root_is_file_not_dir(tmp_path: Path) -> None:
+    target = tmp_path / "not_a_dir"
+    target.write_text("hello")
+    out = list(find_placeholder_candidates(target, ("Cargo.toml",)))
+    assert out == []
+
+
+# ---------------------------------------------------------------------------
+# run_eager_hydrate behaviour pinning
+# ---------------------------------------------------------------------------
+
+
+def test_run_eager_hydrate_passes_path_to_fetch_fn(tmp_path: Path) -> None:
+    target = tmp_path / "Cargo.toml"
+    _touch(target, size=0)
+    seen: List[Path] = []
+
+    def fetch(path: Path) -> bool:
+        seen.append(path)
+        # Simulate hydration: write content so the post-fetch check sees it.
+        path.write_text("[package]\n")
+        return True
+
+    summary = run_eager_hydrate(
+        tmp_path, fetch_fn=fetch, batch_sleep_s=0.0, sleep_fn=lambda _s: None
+    )
+    assert seen == [target]
+    assert summary.hydrated == 1
+
+
+def test_run_eager_hydrate_returns_zero_summary_when_no_candidates(
+    tmp_path: Path,
+) -> None:
+    summary = run_eager_hydrate(
+        tmp_path,
+        fetch_fn=lambda _p: True,
+        batch_sleep_s=0.0,
+        sleep_fn=lambda _s: None,
+    )
+    assert summary == EagerHydrateSummary(hydrated=0, skipped_existing=0, failed=0)
+
+
+def test_run_eager_hydrate_disabled_when_basenames_empty(tmp_path: Path) -> None:
+    _touch(tmp_path / "Cargo.toml", size=0)
+    seen: List[Path] = []
+    summary = run_eager_hydrate(
+        tmp_path,
+        fetch_fn=lambda p: seen.append(p) or True,
+        allowed_basenames=(),
+        batch_sleep_s=0.0,
+        sleep_fn=lambda _s: None,
+    )
+    assert seen == []
+    assert summary.hydrated == 0
+
+
+# ---------------------------------------------------------------------------
+# normalize_eager_hydrate_basenames edge cases
+# ---------------------------------------------------------------------------
+
+
+def test_normalize_basenames_default_when_none() -> None:
+    assert normalize_eager_hydrate_basenames(None) == DEFAULT_EAGER_HYDRATE_BASENAMES
+
+
+def test_normalize_basenames_empty_list_disables_hydrate() -> None:
+    """User can disable eager hydrate entirely with ``[]``."""
+    assert normalize_eager_hydrate_basenames([]) == ()
+
+
+def test_normalize_basenames_dedupes_and_strips() -> None:
+    raw = ["Cargo.toml", "  Cargo.toml  ", "package.json", "", "  "]
+    assert normalize_eager_hydrate_basenames(raw) == (
+        "Cargo.toml",
+        "package.json",
+    )
+
+
+def test_normalize_basenames_drops_non_string_entries() -> None:
+    assert normalize_eager_hydrate_basenames(["x.toml", 42, None, "y.json"]) == (
+        "x.toml",
+        "y.json",
+    )
+
+
+def test_normalize_basenames_garbage_falls_back_to_default() -> None:
+    assert (
+        normalize_eager_hydrate_basenames({"key": "value"})
+        == DEFAULT_EAGER_HYDRATE_BASENAMES
+    )
+
+
+# ---------------------------------------------------------------------------
+# Module-level constants pin (Wave 1.5: PR 14가 같은 default 보존해야 함)
+# ---------------------------------------------------------------------------
+
+
+def test_default_batch_size_is_low_enough_for_edr_pacing() -> None:
+    assert DEFAULT_BATCH_SIZE <= 32
+
+
+def test_default_batch_sleep_is_visibly_paced() -> None:
+    assert DEFAULT_BATCH_SLEEP_S > 0.0
+    assert DEFAULT_BATCH_SLEEP_S <= 1.0
+
+
+def test_default_basenames_contains_core_build_manifests() -> None:
+    """PR 14 (Rust 이관) 후에도 같은 set을 유지해야 한다."""
+    core = {
+        "Cargo.toml",
+        "pyproject.toml",
+        "package.json",
+        "uv.lock",
+    }
+    assert core.issubset(set(DEFAULT_EAGER_HYDRATE_BASENAMES))