fix: error messages while evaluating formulas and handle line boundaries (#35989)

Co-authored-by: Rucha Mahabal <ruchamahabal2@gmail.com>

erpnext/payroll/doctype/salary_slip/salary_slip.py

@@ -46,6 +46,7 @@ from erpnext.payroll.doctype.payroll_period.payroll_period import (
 	get_payroll_period,
 	get_period_factor,
 )
+from erpnext.payroll.utils import prepare_error_msg, sanitize_expression
 from erpnext.utilities.transaction_base import TransactionBase
 
 
@@ -726,32 +727,53 @@ class SalarySlip(TransactionBase):
 
 		return data, default_data
 
-	def eval_condition_and_formula(self, d, data):
+	def eval_condition_and_formula(self, struct_row, data):
 		try:
-			condition = d.condition.strip().replace("\n", " ") if d.condition else None
+			condition = sanitize_expression(struct_row.condition)
 			if condition:
 				if not frappe.safe_eval(condition, self.whitelisted_globals, data):
 					return None
-			amount = d.amount
-			if d.amount_based_on_formula:
-				formula = d.formula.strip().replace("\n", " ") if d.formula else None
+			amount = struct_row.amount
+			if struct_row.amount_based_on_formula:
+				formula = sanitize_expression(struct_row.formula)
 				if formula:
-					amount = flt(frappe.safe_eval(formula, self.whitelisted_globals, data), d.precision("amount"))
+					amount = flt(
+						frappe.safe_eval(formula, self.whitelisted_globals, data), struct_row.precision("amount")
+					)
 			if amount:
-				data[d.abbr] = amount
+				data[struct_row.abbr] = amount
 
 			return amount
 
-		except NameError as err:
-			frappe.throw(
-				_("{0} <br> This error can be due to missing or deleted field.").format(err),
-				title=_("Name error"),
+		except NameError as ne:
+			message = prepare_error_msg(
+				row=struct_row,
+				error=ne,
+				expression=formula or condition,
+				description=_("This error can be due to missing or deleted field."),
 			)
-		except SyntaxError as err:
-			frappe.throw(_("Syntax error in formula or condition: {0}").format(err))
+
+			frappe.throw(message, title=_("Name error"))
+
+		except SyntaxError as se:
+			message = prepare_error_msg(
+				row=struct_row,
+				error=se,
+				expression=formula or condition,
+				description=_("Please check the syntax of your formula."),
+			)
+
+			frappe.throw(message, title=_("Syntax error"))
+
 		except Exception as e:
-			frappe.throw(_("Error in formula or condition: {0}").format(e))
-			raise
+			message = prepare_error_msg(
+				row=struct_row,
+				error=e,
+				expression=formula or condition,
+				description=_("This error can be due to invalid formula or condition."),
+			)
+
+			frappe.throw(message, title=_("Error in formula or condition"))
 
 	def add_employee_benefits(self, payroll_period):
 		for struct_row in self._salary_structure_doc.get("earnings"):

erpnext/payroll/utils.py

@@ -0,0 +1,66 @@
+from typing import Optional
+
+import frappe
+from frappe import _
+from frappe.utils import get_link_to_form
+
+
+def sanitize_expression(string: Optional[str] = None) -> Optional[str]:
+	"""
+	Sanitizes an expression string by removing leading/trailing spaces, newlines, and line boundaries.
+
+	Args:
+	    string (Optional[str]): The input string to be sanitized (default: None).
+
+	Returns:
+	    Optional[str]: The sanitized string or None if the input string is empty or None.
+
+	Example:
+	    expression = "\r\n    gross_pay > 10000\n    "
+	    sanitized_expr = sanitize_expression(expression)
+	"""
+	if not string:
+		return None
+
+	parts = string.strip().splitlines()
+	string = " ".join(parts)
+
+	return string
+
+
+def prepare_error_msg(*, row: dict, error: str, expression: str, description: str) -> str:
+	"""
+	Prepares an error message string with formatted information about the error.
+
+	Args:
+	    row (dict): A dictionary representing the row data.
+	    error (str): The error message.
+	    expression (str): The expression that caused the error.
+	    description (str): Additional description or hint for the error (optional).
+
+	Returns:
+	    str: The formatted error message string.
+
+	Example:
+	    row = {
+	        "parenttype": "Salary Structure",
+	        "parent": "Salary Structure-00001",
+	        "parentfield": "earnings",
+	        "idx": 1
+	    }
+	    error = "SyntaxError: invalid syntax"
+	    expression = " 200 if (gross_pay>10000 and month!=  'Feb')) else 0 "
+	    description = "Check the syntax of the expression."
+	    error_msg = prepare_error_msg(row=row, error=error, expression=expression, description=description)
+	"""
+	msg = _("Error in {0} while evaluating the {1} {2} at row {3}").format(
+		row.parentfield.title(), row.parenttype, get_link_to_form(row.parenttype, row.parent), row.idx
+	)
+	msg += "<br><br>{0}: {1}<br><br>{2}: {3}".format(
+		frappe.bold(_("Expression:")), expression, frappe.bold(_("Error:")), error
+	)
+
+	if description:
+		msg += "<br><br>{0}: {1}".format(frappe.bold(_("Hint:")), description)
+
+	return msg