feat(backend): add QC material batch stockStatus helpers.

Normalize available/exhausted filter values and document remaining_qty matching for list filtering.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/crud/qc_material_batch_stock_status.py

@@ -0,0 +1,24 @@
+"""质检物料入库批次：按剩余数量过滤的语义辅助。"""
+from __future__ import annotations
+
+from decimal import Decimal
+from typing import Any, Optional
+
+
+def normalize_batch_stock_status(stock_status: Optional[str]) -> Optional[str]:
+    """返回 'available' | 'exhausted'；全部 / 空 / 非法 → None（不加剩余数量条件）。"""
+    s = (stock_status or "").strip().lower()
+    if s in ("available", "exhausted"):
+        return s
+    return None
+
+
+def batch_matches_stock_status(remaining_qty: Any, stock_status: Optional[str]) -> bool:
+    """纯函数判定（供单测）；list_batches 用 SQL 等价条件。"""
+    mode = normalize_batch_stock_status(stock_status)
+    if mode is None:
+        return True
+    qty = Decimal(str(remaining_qty if remaining_qty is not None else 0))
+    if mode == "available":
+        return qty > 0
+    return qty == 0

backend/tests/test_qc_material_batch_stock_status.py

@@ -0,0 +1,37 @@
+"""质检物料批次列表：剩余库存过滤语义。"""
+import unittest
+from decimal import Decimal
+
+from app.crud.qc_material_batch_stock_status import (
+    batch_matches_stock_status,
+    normalize_batch_stock_status,
+)
+
+
+class TestNormalizeBatchStockStatus(unittest.TestCase):
+    def test_available_and_exhausted(self):
+        self.assertEqual(normalize_batch_stock_status("available"), "available")
+        self.assertEqual(normalize_batch_stock_status("exhausted"), "exhausted")
+        self.assertEqual(normalize_batch_stock_status(" Available "), "available")
+
+    def test_all_empty_invalid_map_to_none(self):
+        self.assertIsNone(normalize_batch_stock_status(None))
+        self.assertIsNone(normalize_batch_stock_status(""))
+        self.assertIsNone(normalize_batch_stock_status("all"))
+        self.assertIsNone(normalize_batch_stock_status("bogus"))
+
+
+class TestBatchMatchesStockStatus(unittest.TestCase):
+    def test_all_always_true(self):
+        self.assertTrue(batch_matches_stock_status(0, "all"))
+        self.assertTrue(batch_matches_stock_status(1, None))
+
+    def test_available_gt_zero(self):
+        self.assertTrue(batch_matches_stock_status(Decimal("0.1"), "available"))
+        self.assertFalse(batch_matches_stock_status(0, "available"))
+        self.assertFalse(batch_matches_stock_status(Decimal("0"), "available"))
+
+    def test_exhausted_eq_zero(self):
+        self.assertTrue(batch_matches_stock_status(0, "exhausted"))
+        self.assertTrue(batch_matches_stock_status(Decimal("0.0000"), "exhausted"))
+        self.assertFalse(batch_matches_stock_status(1, "exhausted"))