test: added test

(cherry picked from commit 6073f5a6f9)

erpnext/accounts/doctype/sales_invoice/test_sales_invoice.py

@@ -4246,6 +4246,31 @@ class TestSalesInvoice(FrappeTestCase):
 		doc = frappe.get_doc("Project", project.name)
 		self.assertEqual(doc.total_billed_amount, si.grand_total)
 
+	def test_total_billed_amount_with_different_projects(self):
+		# This test case is for checking the scenario where project is set at document level and for **some** child items only, not all
+		from copy import copy
+
+		si = create_sales_invoice(do_not_submit=True)
+
+		project = frappe.new_doc("Project")
+		project.company = "_Test Company"
+		project.project_name = "Test Total Billed Amount"
+		project.save()
+
+		si.project = project.name
+		si.items.append(copy(si.items[0]))
+		si.items.append(copy(si.items[0]))
+		si.items[0].project = project.name
+		si.items[1].project = project.name
+		# Not setting project on last item
+		si.items[1].insert()
+		si.items[2].insert()
+		si.submit()
+
+		project.reload()
+		self.assertIsNone(si.items[2].project)
+		self.assertEqual(project.total_billed_amount, 300)
+
 	def test_pos_returns_with_party_account_currency(self):
 		from erpnext.accounts.doctype.sales_invoice.sales_invoice import make_sales_return