fix(Payroll): calculate loan repayment amount based on payroll end da…

…te instead of posting date (#2154)

* fix(Payroll): calculate loan repayment amount based on payroll end date instead of posting date

- for backdated salary slips fetching loan repayments based on posting date leads to more deductions than earnings sometimes. Process this relative to the payroll dates instead of posting date

* refactor: move out process accrual entries from `get_loan_details`

- doing extra actions in a function named get is misleading

hrms/payroll/doctype/salary_slip/salary_slip_loan_utils.py

@@ -30,8 +30,12 @@ def set_loan_repayment(doc: "SalarySlip"):
 	doc.total_principal_amount = 0
 
 	if not doc.get("loans", []):
-		for loan in _get_loan_details(doc):
-			amounts = calculate_amounts(loan.name, doc.posting_date, "Regular Payment")
+		loan_details = _get_loan_details(doc)
+		if loan_details:
+			process_loan_interest_accruals(loan_details, doc.end_date)
+
+		for loan in loan_details:
+			amounts = calculate_amounts(loan.name, doc.end_date, "Regular Payment")
 
 			if amounts["interest_amount"] or amounts["payable_principal_amount"]:
 				doc.append(
@@ -49,7 +53,7 @@ def set_loan_repayment(doc: "SalarySlip"):
 		doc.set("loans", [])
 
 	for payment in doc.get("loans", []):
-		amounts = calculate_amounts(payment.loan, doc.posting_date, "Regular Payment")
+		amounts = calculate_amounts(payment.loan, doc.end_date, "Regular Payment")
 		total_amount = amounts["interest_amount"] + amounts["payable_principal_amount"]
 		if payment.total_payment > total_amount:
 			frappe.throw(
@@ -68,11 +72,7 @@ def set_loan_repayment(doc: "SalarySlip"):
 		doc.total_loan_repayment += payment.total_payment
 
 
-def _get_loan_details(doc: "SalarySlip"):
-	from lending.loan_management.doctype.process_loan_interest_accrual.process_loan_interest_accrual import (
-		process_loan_interest_accrual_for_term_loans,
-	)
-
+def _get_loan_details(doc: "SalarySlip") -> dict[str, str | bool]:
 	loan_details = frappe.get_all(
 		"Loan",
 		fields=["name", "interest_income_account", "loan_account", "loan_product", "is_term_loan"],
@@ -84,15 +84,19 @@ def _get_loan_details(doc: "SalarySlip"):
 			"status": ("!=", "Closed"),
 		},
 	)
+	return loan_details
 
-	if loan_details:
-		for loan in loan_details:
-			if loan.is_term_loan:
-				process_loan_interest_accrual_for_term_loans(
-					posting_date=doc.posting_date, loan_product=loan.loan_product, loan=loan.name
-				)
 
-	return loan_details
+def process_loan_interest_accruals(loan_details: dict[str, str | bool], posting_date: str):
+	from lending.loan_management.doctype.process_loan_interest_accrual.process_loan_interest_accrual import (
+		process_loan_interest_accrual_for_term_loans,
+	)
+
+	for loan in loan_details:
+		if loan.is_term_loan:
+			process_loan_interest_accrual_for_term_loans(
+				posting_date=posting_date, loan_product=loan.loan_product, loan=loan.name
+			)
 
 
 @if_lending_app_installed