test: add coverage for Stock Ledger Variance report

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

erpnext/stock/report/stock_ledger_variance/test_stock_ledger_variance.py

@@ -0,0 +1,83 @@
+# Copyright (c) 2026, Frappe Technologies Pvt. Ltd. and Contributors
+# See license.txt
+
+import frappe
+
+from erpnext.tests.utils import ERPNextTestSuite
+
+
+class TestStockLedgerVariance(ERPNextTestSuite):
+	def run_report(self, **extra):
+		from erpnext.stock.report.stock_ledger_variance.stock_ledger_variance import execute
+
+		filters = {"company": "_Test Company"}
+		filters.update(extra)
+
+		return execute(frappe._dict(filters))[1]
+
+	def test_healthy_stock_has_no_variance(self):
+		from erpnext.stock.doctype.item.test_item import make_item
+		from erpnext.stock.doctype.stock_entry.stock_entry_utils import make_stock_entry
+
+		item = make_item(properties={"is_stock_item": 1, "valuation_method": "Moving Average"}).name
+
+		make_stock_entry(
+			item_code=item,
+			to_warehouse="_Test Warehouse - _TC",
+			qty=10,
+			rate=100,
+			posting_date="2026-06-01",
+		)
+		make_stock_entry(
+			item_code=item,
+			from_warehouse="_Test Warehouse - _TC",
+			qty=4,
+			posting_date="2026-06-02",
+		)
+
+		# A clean receipt followed by a clean issue keeps the ledger consistent,
+		# so the corruption detector must not flag any entry for this item.
+		data = self.run_report(item_code=item)
+		self.assertFalse([row for row in data if row.get("item_code") == item])
+
+		qty_data = self.run_report(item_code=item, difference_in="Qty")
+		self.assertFalse([row for row in qty_data if row.get("item_code") == item])
+
+	def test_multiple_clean_movements_no_variance(self):
+		from erpnext.stock.doctype.item.test_item import make_item
+		from erpnext.stock.doctype.stock_entry.stock_entry_utils import make_stock_entry
+
+		item = make_item(properties={"is_stock_item": 1, "valuation_method": "Moving Average"}).name
+
+		make_stock_entry(
+			item_code=item,
+			to_warehouse="_Test Warehouse - _TC",
+			qty=10,
+			rate=100,
+			posting_date="2026-06-01",
+		)
+		make_stock_entry(
+			item_code=item,
+			to_warehouse="_Test Warehouse - _TC",
+			qty=5,
+			rate=120,
+			posting_date="2026-06-02",
+		)
+		make_stock_entry(
+			item_code=item,
+			to_warehouse="_Test Warehouse - _TC",
+			qty=8,
+			rate=90,
+			posting_date="2026-06-03",
+		)
+		make_stock_entry(
+			item_code=item,
+			from_warehouse="_Test Warehouse - _TC",
+			qty=6,
+			posting_date="2026-06-04",
+		)
+
+		# Several receipts at different rates plus an issue still produce a
+		# self-consistent ledger, so no variance rows are expected.
+		data = self.run_report(item_code=item)
+		self.assertFalse([row for row in data if row.get("item_code") == item])