diff --git a/erpnext/stock/doctype/stock_reservation_entry/test_stock_reservation_entry.py b/erpnext/stock/doctype/stock_reservation_entry/test_stock_reservation_entry.py
index e7b829e..f64da92 100644
--- a/erpnext/stock/doctype/stock_reservation_entry/test_stock_reservation_entry.py
+++ b/erpnext/stock/doctype/stock_reservation_entry/test_stock_reservation_entry.py
@@ -1,9 +1,251 @@
 # Copyright (c) 2023, Frappe Technologies Pvt. Ltd. and Contributors
 # See license.txt
 
-# import frappe
+import frappe
 from frappe.tests.utils import FrappeTestCase
 
 
 class TestStockReservationEntry(FrappeTestCase):
-	pass
+	def setUp(self) -> None:
+		self.items = create_items()
+		create_material_receipts(self.items)
+
+	def tearDown(self) -> None:
+		return super().tearDown()
+
+	def test_validate_stock_reservation_settings(self) -> None:
+		from erpnext.stock.doctype.stock_reservation_entry.stock_reservation_entry import (
+			validate_stock_reservation_settings,
+		)
+
+		voucher = frappe._dict(
+			{
+				"doctype": "Sales Order",
+			}
+		)
+
+		# Case - 1: When `Stock Reservation` is disabled in `Stock Settings`, throw `ValidationError`
+		update_stock_settings("enable_stock_reservation", 0)
+		self.assertRaises(frappe.ValidationError, validate_stock_reservation_settings, voucher)
+
+		# Case - 2: When `Voucher Type` is not allowed for `Stock Reservation`, throw `ValidationError`
+		update_stock_settings("enable_stock_reservation", 1)
+		voucher.doctype = "NOT ALLOWED"
+		self.assertRaises(frappe.ValidationError, validate_stock_reservation_settings, voucher)
+
+		# Case - 3: When `Stock Reservation` is enabled and `Voucher Type` is allowed
+		update_stock_settings("enable_stock_reservation", 1)
+		voucher.doctype = "Sales Order"
+		self.assertIsNone(validate_stock_reservation_settings(voucher), None)
+
+	def test_get_available_qty_to_reserve(self) -> None:
+		from erpnext.stock.doctype.stock_reservation_entry.stock_reservation_entry import (
+			get_available_qty_to_reserve,
+		)
+		from erpnext.stock.utils import get_stock_balance
+
+		item_code, warehouse = "SR Item 1", "_Test Warehouse - _TC"
+
+		# Case - 1: When `Reserved Qty` is `0`, Available Qty to Reserve = Actual Qty
+		cancel_all_stock_reservation_entries()
+		available_qty_to_reserve = get_available_qty_to_reserve(item_code, warehouse)
+		expected_available_qty_to_reserve = get_stock_balance(item_code, warehouse)
+
+		self.assertEqual(available_qty_to_reserve, expected_available_qty_to_reserve)
+
+		# Case - 2: When `Reserved Qty` is `> 0`, Available Qty to Reserve = Actual Qty - Reserved Qty
+		sre = make_stock_reservation_entry(
+			item_code=item_code,
+			warehouse=warehouse,
+			ignore_validate=True,
+		)
+		available_qty_to_reserve = get_available_qty_to_reserve(item_code, warehouse)
+		expected_available_qty_to_reserve = get_stock_balance(item_code, warehouse) - sre.reserved_qty
+
+		self.assertEqual(available_qty_to_reserve, expected_available_qty_to_reserve)
+
+	def test_update_status(self) -> None:
+		sre = make_stock_reservation_entry(
+			reserved_qty=30,
+			ignore_validate=True,
+			do_not_submit=True,
+		)
+
+		# Draft: When DocStatus is `0`
+		sre.load_from_db()
+		self.assertEqual(sre.status, "Draft")
+
+		# Partially Reserved: When DocStatus is `1` and `Reserved Qty` < `Voucher Qty`
+		sre.submit()
+		sre.load_from_db()
+		self.assertEqual(sre.status, "Partially Reserved")
+
+		# Reserved: When DocStatus is `1` and `Reserved Qty` = `Voucher Qty`
+		sre.reserved_qty = sre.voucher_qty
+		sre.db_update()
+		sre.update_status()
+		sre.load_from_db()
+		self.assertEqual(sre.status, "Reserved")
+
+		# Partially Delivered: When DocStatus is `1` and (0 < `Delivered Qty` < `Voucher Qty`)
+		sre.delivered_qty = 10
+		sre.db_update()
+		sre.update_status()
+		sre.load_from_db()
+		self.assertEqual(sre.status, "Partially Delivered")
+
+		# Delivered: When DocStatus is `1` and `Delivered Qty` = `Voucher Qty`
+		sre.delivered_qty = sre.voucher_qty
+		sre.db_update()
+		sre.update_status()
+		sre.load_from_db()
+		self.assertEqual(sre.status, "Delivered")
+
+		# Cancelled: When DocStatus is `2`
+		sre.cancel()
+		sre.load_from_db()
+		self.assertEqual(sre.status, "Cancelled")
+
+	def test_update_reserved_qty_in_voucher(self) -> None:
+		from erpnext.selling.doctype.sales_order.test_sales_order import make_sales_order
+
+		item_code, warehouse = "SR Item 1", "_Test Warehouse - _TC"
+
+		# Step - 1: Enable `Stock Reservation`
+		update_stock_settings("enable_stock_reservation", 1)
+
+		# Step - 2: Create a `Sales Order`
+		so = make_sales_order(
+			item_code=item_code,
+			warehouse=warehouse,
+			qty=50,
+			rate=100,
+			do_not_submit=True,
+		)
+		so.reserve_stock = 0  # Stock Reservation Entries won't be created on submit
+		so.items[0].reserve_stock = 1
+		so.save()
+		so.submit()
+
+		# Step - 3: Create a `Stock Reservation Entry[1]` for the `Sales Order Item`
+		sre1 = make_stock_reservation_entry(
+			item_code=item_code,
+			warehouse=warehouse,
+			voucher_type="Sales Order",
+			voucher_no=so.name,
+			voucher_detail_no=so.items[0].name,
+			reserved_qty=30,
+		)
+
+		so.load_from_db()
+		sre1.load_from_db()
+		self.assertEqual(sre1.status, "Partially Reserved")
+		self.assertEqual(so.items[0].stock_reserved_qty, sre1.reserved_qty)
+
+		# Step - 4: Create a `Stock Reservation Entry[2]` for the `Sales Order Item`
+		sre2 = make_stock_reservation_entry(
+			item_code=item_code,
+			warehouse=warehouse,
+			voucher_type="Sales Order",
+			voucher_no=so.name,
+			voucher_detail_no=so.items[0].name,
+			reserved_qty=20,
+		)
+
+		so.load_from_db()
+		sre2.load_from_db()
+		self.assertEqual(sre1.status, "Partially Reserved")
+		self.assertEqual(so.items[0].stock_reserved_qty, sre1.reserved_qty + sre2.reserved_qty)
+
+		# Step - 5: Cancel `Stock Reservation Entry[1]`
+		sre1.cancel()
+		so.load_from_db()
+		sre1.load_from_db()
+		self.assertEqual(sre1.status, "Cancelled")
+		self.assertEqual(so.items[0].stock_reserved_qty, sre2.reserved_qty)
+
+		# Step - 6: Cancel `Stock Reservation Entry[2]`
+		sre2.cancel()
+		so.load_from_db()
+		sre2.load_from_db()
+		self.assertEqual(sre1.status, "Cancelled")
+		self.assertEqual(so.items[0].stock_reserved_qty, 0)
+
+
+def update_stock_settings(field: str, value: any) -> None:
+	frappe.db.set_single_value("Stock Settings", field, value)
+
+
+def create_items() -> dict:
+	from erpnext.stock.doctype.item.test_item import make_item
+
+	items_details = {
+		# Stock Items
+		"SR Item 1": {"is_stock_item": 1, "valuation_rate": 100},
+		"SR Item 2": {"is_stock_item": 1, "valuation_rate": 200, "stock_uom": "Kg"},
+		# Batch Items
+		"SR Batch Item 1": {"is_stock_item": 1, "valuation_rate": 100},
+		"SR Batch Item 2": {"is_stock_item": 1, "valuation_rate": 200, "stock_uom": "Kg"},
+		# Serial Items
+		"SR Serial Item 1": {"is_stock_item": 1, "valuation_rate": 100},
+		"SR Serial Item 2": {"is_stock_item": 1, "valuation_rate": 200, "stock_uom": "Kg"},
+		# Batch and Serial Items
+		"SR Batch and Serial Item 1": {"is_stock_item": 1, "valuation_rate": 100},
+		"SR Batch and Serial Item 2": {"is_stock_item": 1, "valuation_rate": 200, "stock_uom": "Kg"},
+	}
+
+	items = {}
+	for item_code, properties in items_details.items():
+		items[item_code] = make_item(item_code, properties)
+
+	return items
+
+
+def create_material_receipts(
+	items: dict, warehouse: str = "_Test Warehouse - _TC", qty: float = 100
+) -> None:
+	from erpnext.stock.doctype.stock_entry.test_stock_entry import make_stock_entry
+
+	for item in items.values():
+		if item.is_stock_item:
+			make_stock_entry(
+				item_code=item.item_code,
+				qty=qty,
+				to_warehouse=warehouse,
+				rate=item.valuation_rate,
+				purpose="Material Receipt",
+			)
+
+
+def cancel_all_stock_reservation_entries() -> None:
+	sre_list = frappe.db.get_all("Stock Reservation Entry", filters={"docstatus": 1}, pluck="name")
+
+	for sre in sre_list:
+		frappe.get_doc("Stock Reservation Entry", sre).cancel()
+
+
+def make_stock_reservation_entry(**args):
+	doc = frappe.new_doc("Stock Reservation Entry")
+	args = frappe._dict(args)
+
+	doc.item_code = args.item_code or "SR Item 1"
+	doc.warehouse = args.warehouse or "_Test Warehouse - _TC"
+	doc.voucher_type = args.voucher_type
+	doc.voucher_no = args.voucher_no
+	doc.voucher_detail_no = args.voucher_detail_no
+	doc.available_qty = args.available_qty or 100
+	doc.voucher_qty = args.voucher_qty or 50
+	doc.stock_uom = args.stock_uom or "Nos"
+	doc.reserved_qty = args.reserved_qty or 50
+	doc.delivered_qty = args.delivered_qty or 0
+	doc.company = args.company or "_Test Company"
+
+	if args.ignore_validate:
+		doc.flags.ignore_validate = True
+
+	if not args.do_not_save:
+		doc.save()
+		if not args.do_not_submit:
+			doc.submit()
+
+	return doc