fix: Provision to apply early payment discount if payment is recorded late

- Party could have paid on time but payment is recorded late
- Prompt for reference date so that discount is applied while mapping
- Prompt only if discount in payment schedule of valid doctypes
- test: Reference date and impact on PE
- `make_payment_entry` (JS) must be able to access `this`

erpnext/accounts/doctype/payment_entry/payment_entry.py

@@ -1686,7 +1686,14 @@ def get_reference_details(reference_doctype, reference_name, party_account_curre
 
 @frappe.whitelist()
 def get_payment_entry(
-	dt, dn, party_amount=None, bank_account=None, bank_amount=None, party_type=None, payment_type=None
+	dt,
+	dn,
+	party_amount=None,
+	bank_account=None,
+	bank_amount=None,
+	party_type=None,
+	payment_type=None,
+	reference_date=None,
 ):
 	reference_doc = None
 	doc = frappe.get_doc(dt, dn)
@@ -1713,8 +1720,9 @@ def get_payment_entry(
 		dt, party_account_currency, bank, outstanding_amount, payment_type, bank_amount, doc
 	)
 
+	reference_date = getdate(reference_date)
 	paid_amount, received_amount, discount_amount, valid_discounts = apply_early_payment_discount(
-		paid_amount, received_amount, doc, party_account_currency
+		paid_amount, received_amount, doc, party_account_currency, reference_date
 	)
 
 	pe = frappe.new_doc("Payment Entry")
@@ -1722,6 +1730,7 @@ def get_payment_entry(
 	pe.company = doc.company
 	pe.cost_center = doc.get("cost_center")
 	pe.posting_date = nowdate()
+	pe.reference_date = reference_date
 	pe.mode_of_payment = doc.get("mode_of_payment")
 	pe.party_type = party_type
 	pe.party = doc.get(scrub(party_type))
@@ -1931,7 +1940,9 @@ def set_paid_amount_and_received_amount(
 	return paid_amount, received_amount
 
 
-def apply_early_payment_discount(paid_amount, received_amount, doc, party_account_currency):
+def apply_early_payment_discount(
+	paid_amount, received_amount, doc, party_account_currency, reference_date
+):
 	total_discount = 0
 	valid_discounts = []
 	eligible_for_payments = ["Sales Order", "Sales Invoice", "Purchase Order", "Purchase Invoice"]
@@ -1940,7 +1951,7 @@ def apply_early_payment_discount(paid_amount, received_amount, doc, party_accoun
 
 	if doc.doctype in eligible_for_payments and has_payment_schedule:
 		for term in doc.payment_schedule:
-			if not term.discounted_amount and term.discount and getdate(nowdate()) <= term.discount_date:
+			if not term.discounted_amount and term.discount and reference_date <= term.discount_date:
 
 				if term.discount_type == "Percentage":
 					grand_total = doc.get("grand_total") if is_multi_currency else doc.get("base_grand_total")

erpnext/accounts/doctype/payment_entry/test_payment_entry.py

@@ -302,6 +302,15 @@ class TestPaymentEntry(FrappeTestCase):
 		si.save()
 		si.submit()
 
+		# Set reference date past discount cut off date
+		pe_1 = get_payment_entry(
+			"Sales Invoice",
+			si.name,
+			bank_account="_Test Cash - _TC",
+			reference_date=frappe.utils.add_days(si.posting_date, 2),
+		)
+		self.assertEqual(pe_1.paid_amount, 236.0)  # discount not applied
+
 		pe = get_payment_entry("Sales Invoice", si.name, bank_account="_Test Cash - _TC")
 		self.assertEqual(pe.references[0].allocated_amount, 236.0)
 		self.assertEqual(pe.paid_amount, 186)

erpnext/accounts/doctype/purchase_invoice/purchase_invoice.js

@@ -82,7 +82,11 @@ erpnext.accounts.PurchaseInvoice = class PurchaseInvoice extends erpnext.buying.
 
 		if(doc.docstatus == 1 && doc.outstanding_amount != 0
 			&& !(doc.is_return && doc.return_against) && !doc.on_hold) {
-			this.frm.add_custom_button(__('Payment'), this.make_payment_entry, __('Create'));
+			this.frm.add_custom_button(
+				__('Payment'),
+				() => this.make_payment_entry(),
+				__('Create')
+			);
 			cur_frm.page.set_inner_btn_group_as_primary(__('Create'));
 		}
 

erpnext/accounts/doctype/sales_invoice/sales_invoice.js

@@ -93,9 +93,12 @@ erpnext.accounts.SalesInvoiceController = class SalesInvoiceController extends e
 
 		if (doc.docstatus == 1 && doc.outstanding_amount!=0
 			&& !(cint(doc.is_return) && doc.return_against)) {
-			cur_frm.add_custom_button(__('Payment'),
-				this.make_payment_entry, __('Create'));
-			cur_frm.page.set_inner_btn_group_as_primary(__('Create'));
+			this.frm.add_custom_button(
+				__('Payment'),
+				() => this.make_payment_entry(),
+				__('Create')
+			);
+			this.frm.page.set_inner_btn_group_as_primary(__('Create'));
 		}
 
 		if(doc.docstatus==1 && !doc.is_return) {

erpnext/buying/doctype/purchase_order/purchase_order.js

@@ -236,7 +236,11 @@ erpnext.buying.PurchaseOrderController = class PurchaseOrderController extends e
 							this.make_purchase_invoice, __('Create'));
 
 					if(flt(doc.per_billed) < 100 && doc.status != "Delivered") {
-						cur_frm.add_custom_button(__('Payment'), cur_frm.cscript.make_payment_entry, __('Create'));
+						this.frm.add_custom_button(
+							__('Payment'),
+							() => this.make_payment_entry(),
+							__('Create')
+						);
 					}
 
 					if(flt(doc.per_billed) < 100) {

erpnext/public/js/controllers/transaction.js

@@ -1897,20 +1897,60 @@ erpnext.TransactionController = class TransactionController extends erpnext.taxe
 	}
 
 	make_payment_entry() {
+		let via_journal_entry = this.frm.doc.__onload && this.frm.doc.__onload.make_payment_via_journal_entry;
+		if(this.has_discount_in_schedule() && !via_journal_entry) {
+			// If early payment discount is applied, ask user for reference date
+			this.prompt_user_for_reference_date();
+		} else {
+			this.make_mapped_payment_entry();
+		}
+	}
+
+	make_mapped_payment_entry(args) {
+		var me = this;
+		args = args || { "dt": this.frm.doc.doctype, "dn": this.frm.doc.name };
 		return frappe.call({
-			method: cur_frm.cscript.get_method_for_payment(),
-			args: {
-				"dt": cur_frm.doc.doctype,
-				"dn": cur_frm.doc.name
-			},
+			method: me.get_method_for_payment(),
+			args: args,
 			callback: function(r) {
 				var doclist = frappe.model.sync(r.message);
 				frappe.set_route("Form", doclist[0].doctype, doclist[0].name);
-				// cur_frm.refresh_fields()
 			}
 		});
 	}
 
+	prompt_user_for_reference_date(){
+		var me = this;
+		frappe.prompt({
+			label: __("Cheque/Reference Date"),
+			fieldname: "reference_date",
+			fieldtype: "Date",
+			reqd: 1,
+		}, (values) => {
+			let args = {
+				"dt": me.frm.doc.doctype,
+				"dn": me.frm.doc.name,
+				"reference_date": values.reference_date
+			}
+			me.make_mapped_payment_entry(args);
+		},
+		__("Reference Date for Early Payment Discount"),
+		__("Continue")
+		);
+	}
+
+	has_discount_in_schedule() {
+		let is_eligible = in_list(
+			["Sales Order", "Sales Invoice", "Purchase Order", "Purchase Invoice"],
+			this.frm.doctype
+		);
+		let has_payment_schedule = this.frm.doc.payment_schedule && this.frm.doc.payment_schedule.length;
+		if(!is_eligible || !has_payment_schedule) return false;
+
+		let has_discount = this.frm.doc.payment_schedule.some(row => row.discount_date);
+		return has_discount;
+	}
+
 	make_quality_inspection() {
 		let data = [];
 		const fields = [