From 102ef29d6ba62a36cd9d8d83390312ec5360b13d Mon Sep 17 00:00:00 2001
From: Piyush Singhania <piyushsinghania28@gmail.com>
Date: Fri, 29 Oct 2021 18:26:45 +0530
Subject: [PATCH] Added validation to give error message when trying to pay
 excess amount for an invoice

---
 models/doctype/Payment/Payment.js | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/models/doctype/Payment/Payment.js b/models/doctype/Payment/Payment.js
index c61318da..76240afa 100644
--- a/models/doctype/Payment/Payment.js
+++ b/models/doctype/Payment/Payment.js
@@ -1,3 +1,4 @@
+const frappe = require('frappejs');
 const utils = require('../../../accounting/utils');
 
 module.exports = {
@@ -102,7 +103,15 @@ module.exports = {
       label: 'Amount',
       fieldtype: 'Currency',
       required: 1,
-      formula: doc => doc.getSum('for', 'amount')
+      formula: doc => doc.getSum('for', 'amount'),
+      validate(value, doc) {
+        let amount = doc.getSum('for', 'amount');
+        let isValid = amount >= value && value > 0 ? true : false;
+
+        if (!isValid) {
+          throw new frappe.errors.ValidationError(`Invalid amount ${value}`);
+        }
+      }
     },
     {
       fieldname: 'writeoff',