fix: Stock Ageing Transfer Bucket logic for Repack Entry with split batch rows

erpnext/stock/report/stock_ageing/stock_ageing.py

@@ -12,6 +12,7 @@
 from erpnext.stock.doctype.serial_no.serial_no import get_serial_nos
 
 Filters = frappe._dict
+precision = cint(frappe.db.get_single_value("System Settings", "float_precision"))
 
 def execute(filters: Filters = None) -> Tuple:
 	to_date = filters["to_date"]
@@ -48,10 +49,13 @@ def format_report_data(filters: Filters, item_details: Dict, to_date: str) -> Li
 		if filters.get("show_warehouse_wise_stock"):
 			row.append(details.warehouse)
 
-		row.extend([item_dict.get("total_qty"), average_age,
+		row.extend([
+			flt(item_dict.get("total_qty"), precision),
+			average_age,
 			range1, range2, range3, above_range3,
 			earliest_age, latest_age,
-			details.stock_uom])
+			details.stock_uom
+		])
 
 		data.append(row)
 
@@ -79,13 +83,13 @@ def get_range_age(filters: Filters, fifo_queue: List, to_date: str, item_dict: D
 		qty = flt(item[0]) if not item_dict["has_serial_no"] else 1.0
 
 		if age <= filters.range1:
-			range1 += qty
+			range1 = flt(range1 + qty, precision)
 		elif age <= filters.range2:
-			range2 += qty
+			range2 = flt(range2 + qty, precision)
 		elif age <= filters.range3:
-			range3 += qty
+			range3 = flt(range3 + qty, precision)
 		else:
-			above_range3 += qty
+			above_range3 = flt(above_range3 + qty, precision)
 
 	return range1, range2, range3, above_range3
 
@@ -286,14 +290,16 @@ def __init_key_stores(self, row: Dict) -> Tuple:
 	def __compute_incoming_stock(self, row: Dict, fifo_queue: List, transfer_key: Tuple, serial_nos: List):
 		"Update FIFO Queue on inward stock."
 
-		if self.transferred_item_details.get(transfer_key):
+		transfer_data = self.transferred_item_details.get(transfer_key)
+		if transfer_data:
 			# inward/outward from same voucher, item & warehouse
-			slot = self.transferred_item_details[transfer_key].pop(0)
-			fifo_queue.append(slot)
+			# eg: Repack with same item, Stock reco for batch item
+			# consume transfer data and add stock to fifo queue
+			self.__adjust_incoming_transfer_qty(transfer_data, fifo_queue, row)
 		else:
 			if not serial_nos:
-				if fifo_queue and flt(fifo_queue[0][0]) < 0:
-					# neutralize negative stock by adding positive stock
+				if fifo_queue and flt(fifo_queue[0][0]) <= 0:
+					# neutralize 0/negative stock by adding positive stock
 					fifo_queue[0][0] += flt(row.actual_qty)
 					fifo_queue[0][1] = row.posting_date
 				else:
@@ -324,7 +330,7 @@ def __compute_outgoing_stock(self, row: Dict, fifo_queue: List, transfer_key: Tu
 			elif not fifo_queue:
 				# negative stock, no balance but qty yet to consume
 				fifo_queue.append([-(qty_to_pop), row.posting_date])
-				self.transferred_item_details[transfer_key].append([row.actual_qty, row.posting_date])
+				self.transferred_item_details[transfer_key].append([qty_to_pop, row.posting_date])
 				qty_to_pop = 0
 			else:
 				# qty to pop < slot qty, ample balance
@@ -333,6 +339,33 @@ def __compute_outgoing_stock(self, row: Dict, fifo_queue: List, transfer_key: Tu
 				self.transferred_item_details[transfer_key].append([qty_to_pop, slot[1]])
 				qty_to_pop = 0
 
+	def __adjust_incoming_transfer_qty(self, transfer_data: Dict, fifo_queue: List, row: Dict):
+		"Add previously removed stock back to FIFO Queue."
+		transfer_qty_to_pop = flt(row.actual_qty)
+
+		def add_to_fifo_queue(slot):
+			if fifo_queue and flt(fifo_queue[0][0]) <= 0:
+				# neutralize 0/negative stock by adding positive stock
+				fifo_queue[0][0] += flt(slot[0])
+				fifo_queue[0][1] = slot[1]
+			else:
+				fifo_queue.append(slot)
+
+		while transfer_qty_to_pop:
+			if transfer_data and 0 < transfer_data[0][0] <= transfer_qty_to_pop:
+				# bucket qty is not enough, consume whole
+				transfer_qty_to_pop -= transfer_data[0][0]
+				add_to_fifo_queue(transfer_data.pop(0))
+			elif not transfer_data:
+				# transfer bucket is empty, extra incoming qty
+				add_to_fifo_queue([transfer_qty_to_pop, row.posting_date])
+				transfer_qty_to_pop = 0
+			else:
+				# ample bucket qty to consume
+				transfer_data[0][0] -= transfer_qty_to_pop
+				add_to_fifo_queue([transfer_qty_to_pop, transfer_data[0][1]])
+				transfer_qty_to_pop = 0
+
 	def __update_balances(self, row: Dict, key: Union[Tuple, str]):
 		self.item_details[key]["qty_after_transaction"] = row.qty_after_transaction
 

erpnext/stock/report/stock_ageing/stock_ageing_fifo_logic.md

@@ -71,4 +71,39 @@ Date | Qty | Queue
 2nd  | -60 | [[-10, 1-12-2021]]
 3rd  | +5  | [[-5, 3-12-2021]]
 4th  | +10 | [[5, 4-12-2021]]
-4th  | +20 | [[5, 4-12-2021], [20, 4-12-2021]]
+4th  | +20 | [[5, 4-12-2021], [20, 4-12-2021]]
+
+### Concept of Transfer Qty Bucket
+In the case of **Repack**, Quantity that comes in, isn't really incoming. It is just new stock repurposed from old stock, due to incoming-outgoing of the same warehouse.
+
+Here, stock is consumed from the FIFO Queue. It is then re-added back to the queue.
+While adding stock back to the queue we need to know how much to add.
+For this we need to keep track of how much was previously consumed.
+Hence we use **Transfer Qty Bucket**.
+
+While re-adding stock, we try to add buckets that were consumed earlier (date intact), to maintain correctness.
+
+#### Case 1: Same Item-Warehouse in Repack
+Eg:
+-------------------------------------------------------------------------------------
+Date | Qty   | Voucher |             FIFO Queue           	   | Transfer Qty Buckets
+-------------------------------------------------------------------------------------
+1st  | +500  |  PR     | [[500, 1-12-2021]]   				   |
+2nd  | -50   |  Repack | [[450, 1-12-2021]]   				   | [[50, 1-12-2021]]
+2nd  | +50   |  Repack | [[450, 1-12-2021], [50, 1-12-2021]]   | []
+
+- The balance at the end is restored back to 500
+- However, the initial 500 qty bucket is now split into 450 and 50, with the same date
+- The net effect is the same as that before the Repack
+
+#### Case 2: Same Item-Warehouse in Repack with Split Consumption rows
+Eg:
+-------------------------------------------------------------------------------------
+Date | Qty   | Voucher |             FIFO Queue           	   | Transfer Qty Buckets
+-------------------------------------------------------------------------------------
+1st  | +500  |  PR     | [[500, 1-12-2021]]   				   |
+2nd  | -50   |  Repack | [[450, 1-12-2021]]   				   | [[50, 1-12-2021]]
+2nd  | -50   |  Repack | [[400, 1-12-2021]]   				   | [[50, 1-12-2021],
+-	 |		 |		   |									   |[50, 1-12-2021]]
+2nd  | +100  |  Repack | [[400, 1-12-2021], [50, 1-12-2021],   | []
+-	 |		 |		   | [50, 1-12-2021]]					   |