import json import frappe from frappe.utils import flt from erpnext.tests.utils import ERPNextTestSuite, change_settings class TestTaxesAndTotals(ERPNextTestSuite): def setUp(self): self.doc = frappe.get_doc( { "doctype": "Sales Invoice", "customer": "_Test Customer", "company": "_Test Company", "currency": "INR", "conversion_rate": 1, "items": [ { "item_code": "_Test Item", "qty": 1, "rate": 100, "income_account": "Sales - _TC", "expense_account": "Cost of Goods Sold - _TC", "cost_center": "_Test Cost Center - _TC", } ], "taxes": [], } ) def test_item_wise_tax_detail(self): # Test On Net Total self.doc.append( "taxes", { "charge_type": "On Net Total", "account_head": "_Test Account VAT - _TC", "cost_center": "_Test Cost Center - _TC", "description": "VAT", "rate": 10, }, ) # Test On Previous Row Amount self.doc.append( "taxes", { "charge_type": "On Previous Row Amount", "account_head": "_Test Account Service Tax - _TC", "cost_center": "_Test Cost Center - _TC", "description": "Service Tax", "rate": 14, "row_id": 1, }, ) # Test On Previous Row Total self.doc.append( "taxes", { "charge_type": "On Previous Row Total", "account_head": "_Test Account Customs Duty - _TC", "cost_center": "_Test Cost Center - _TC", "description": "Customs Duty", "rate": 5, "row_id": 2, }, ) # Test On Item Quantity self.doc.append( "taxes", { "charge_type": "On Item Quantity", "account_head": "_Test Account Shipping Charges - _TC", "cost_center": "_Test Cost Center - _TC", "description": "Shipping", "rate": 50, }, ) self.doc.save() expected_values = [ { "item_row": self.doc.items[0].name, "tax_row": self.doc.taxes[0].name, "rate": 10.0, "amount": 10.0, "taxable_amount": 100.0, }, { "item_row": self.doc.items[0].name, "tax_row": self.doc.taxes[1].name, "rate": 14.0, "amount": 1.4, "taxable_amount": 10.0, }, { "item_row": self.doc.items[0].name, "tax_row": self.doc.taxes[2].name, "rate": 5.0, "amount": 5.57, "taxable_amount": 111.4, }, { "item_row": self.doc.items[0].name, "tax_row": self.doc.taxes[3].name, "rate": 50.0, "amount": 50.0, "taxable_amount": 0.0, }, ] actual_values = [ { "item_row": row.item_row, "tax_row": row.tax_row, "rate": row.rate, "amount": row.amount, "taxable_amount": row.taxable_amount, } for row in self.doc.item_wise_tax_details ] self.assertEqual(actual_values, expected_values) @change_settings("Selling Settings", {"allow_multiple_items": 1}) def test_item_wise_tax_detail_high_conversion_rate(self): """ With a high conversion rate (e.g. USD -> KRW ~1300), independently rounding each item's base tax amount causes per-item errors that accumulate and exceed the 0.5-unit safety threshold, raising a validation error. Error diffusion fixes this: the cumulative base total after the last item equals base_tax_amount_after_discount_amount exactly, so the sum of all per-item amounts is always exact regardless of item count or rate magnitude. Analytically with conversion_rate=1300, rate=7.77 x3 items, VAT 16%: per-item txn tax = 1.2432 OLD independent: flt(1.2432 * 1300, 2) = 1616.16 -> sum 4848.48 expected base: flt(flt(3.7296, 2) * 1300, 0) = flt(3.73 * 1300, 0) = 4849 diff = 0.52 -> exceeds 0.5 threshold -> would throw with old code """ doc = frappe.get_doc( { "doctype": "Sales Invoice", "customer": "_Test Customer", "company": "_Test Company", "currency": "USD", "debit_to": "_Test Receivable USD - _TC", "conversion_rate": 1300, "items": [ { "item_code": "_Test Item", "qty": 1, "rate": 7.77, "income_account": "Sales - _TC", "expense_account": "Cost of Goods Sold - _TC", "cost_center": "_Test Cost Center - _TC", }, { "item_code": "_Test Item", "qty": 1, "rate": 7.77, "income_account": "Sales - _TC", "expense_account": "Cost of Goods Sold - _TC", "cost_center": "_Test Cost Center - _TC", }, { "item_code": "_Test Item", "qty": 1, "rate": 7.77, "income_account": "Sales - _TC", "expense_account": "Cost of Goods Sold - _TC", "cost_center": "_Test Cost Center - _TC", }, ], "taxes": [ { "charge_type": "On Net Total", "account_head": "_Test Account VAT - _TC", "cost_center": "_Test Cost Center - _TC", "description": "VAT", "rate": 16, }, { "charge_type": "On Previous Row Amount", "account_head": "_Test Account Service Tax - _TC", "cost_center": "_Test Cost Center - _TC", "description": "Service Tax", "rate": 10, "row_id": 1, }, ], } ) doc.save() details_by_tax = {} for detail in doc.item_wise_tax_details: bucket = details_by_tax.setdefault(detail.tax_row, 0.0) details_by_tax[detail.tax_row] = bucket + detail.amount for tax in doc.taxes: self.assertEqual(details_by_tax[tax.name], tax.base_tax_amount_after_discount_amount) @change_settings("Selling Settings", {"allow_multiple_items": 1}) def test_rounding_in_item_wise_tax_details(self): """ This test verifies the amounts are properly rounded. """ doc = frappe.get_doc( { "doctype": "Sales Invoice", "customer": "_Test Customer", "company": "_Test Company", "currency": "INR", "conversion_rate": 1, "items": [ { "item_code": "_Test Item", "qty": 5, "rate": 20, "income_account": "Sales - _TC", "expense_account": "Cost of Goods Sold - _TC", "cost_center": "_Test Cost Center - _TC", }, { "item_code": "_Test Item", "qty": 3, "rate": 19, "income_account": "Sales - _TC", "expense_account": "Cost of Goods Sold - _TC", "cost_center": "_Test Cost Center - _TC", }, { "item_code": "_Test Item", "qty": 1, "rate": 1000, "income_account": "Sales - _TC", "expense_account": "Cost of Goods Sold - _TC", "cost_center": "_Test Cost Center - _TC", }, ], "taxes": [ { "charge_type": "On Net Total", "account_head": "_Test Account VAT - _TC", "cost_center": "_Test Cost Center - _TC", "description": "VAT", "rate": 9, }, ], } ) doc.save() # item 1: taxable=100, tax=9.0; item 2: taxable=57, tax=5.13; item 3: taxable=1000, tax=90.0 # error diffusion: 14.13 - 9.0 = 5.130000000000001 without rounding for detail in doc.item_wise_tax_details: self.assertEqual(detail.amount, flt(detail.amount, detail.precision("amount"))) def test_item_wise_tax_detail_with_multi_currency_with_single_item(self): """ When the tax amount (in transaction currency) has more decimals than the field precision, rounding must happen *before* multiplying by conversion_rate — the same order used by _set_in_company_currency. """ doc = frappe.get_doc( { "doctype": "Sales Invoice", "customer": "_Test Customer", "company": "_Test Company", "currency": "USD", "debit_to": "_Test Receivable USD - _TC", "conversion_rate": 129.99, "items": [ { "item_code": "_Test Item", "qty": 1, "rate": 47.41, "income_account": "Sales - _TC", "expense_account": "Cost of Goods Sold - _TC", "cost_center": "_Test Cost Center - _TC", } ], "taxes": [ { "charge_type": "On Net Total", "account_head": "_Test Account VAT - _TC", "cost_center": "_Test Cost Center - _TC", "description": "VAT", "rate": 16, }, ], } ) doc.save() tax = doc.taxes[0] detail = doc.item_wise_tax_details[0] self.assertEqual(detail.amount, tax.base_tax_amount_after_discount_amount) @change_settings("Selling Settings", {"allow_multiple_items": 1}) def test_not_applicable_tax_in_item_tax_template(self): """Test that items with 'not applicable' tax don't contribute to net amount of that tax.""" template_7pct = frappe.get_doc( { "doctype": "Item Tax Template", "title": "_Test VAT 7% Template", "company": "_Test Company", "taxes": [ { "tax_type": "_Test Account VAT - _TC", "tax_rate": 7, }, { "tax_type": "_Test Account Service Tax - _TC", "tax_rate": 0, "not_applicable": 1, }, ], } ).insert(ignore_if_duplicate=True) template_19pct = frappe.get_doc( { "doctype": "Item Tax Template", "title": "_Test VAT 19% Template", "company": "_Test Company", "taxes": [ { "tax_type": "_Test Account VAT - _TC", "tax_rate": 0, }, { "tax_type": "_Test Account Service Tax - _TC", "tax_rate": 19, }, ], } ).insert(ignore_if_duplicate=True) self.doc.items[0].item_tax_template = template_7pct.name self.doc.append( "items", { "item_code": "_Test Item", "qty": 1, "rate": 100, "income_account": "Sales - _TC", "expense_account": "Cost of Goods Sold - _TC", "cost_center": "_Test Cost Center - _TC", "item_tax_template": template_19pct.name, }, ) self.doc.append( "taxes", { "charge_type": "On Net Total", "account_head": "_Test Account VAT - _TC", "cost_center": "_Test Cost Center - _TC", "description": "VAT 7%", "rate": 7, }, ) self.doc.append( "taxes", { "charge_type": "On Net Total", "account_head": "_Test Account Service Tax - _TC", "cost_center": "_Test Cost Center - _TC", "description": "VAT 19%", "rate": 19, }, ) self.doc.save() # VAT 7%: Both items contribute (Item 2 has 0% rate, not "not applicable") self.assertEqual(self.doc.taxes[0].net_amount, 200.0) # Service Tax 19%: Only Item 2 contributes (Item 1 has not_applicable) self.assertEqual(self.doc.taxes[1].net_amount, 100.0) expected_values = [ { "item_row": self.doc.items[0].name, "tax_row": self.doc.taxes[0].name, "rate": 7.0, "amount": 7.0, "taxable_amount": 100.0, }, { "item_row": self.doc.items[1].name, "tax_row": self.doc.taxes[0].name, "rate": 0.0, "amount": 0.0, "taxable_amount": 100.0, }, { "item_row": self.doc.items[1].name, "tax_row": self.doc.taxes[1].name, "rate": 19.0, "amount": 19.0, "taxable_amount": 100.0, }, ] actual_values = [ { "item_row": row.item_row, "tax_row": row.tax_row, "rate": row.rate, "amount": row.amount, "taxable_amount": row.taxable_amount, } for row in self.doc.item_wise_tax_details ] self.assertEqual(actual_values, expected_values) def test_not_applicable_tax_in_item_tax_template_with_different_items(self): """Test that items with 'not applicable' tax don't contribute to net amount of that tax.""" template_7pct = frappe.get_doc( { "doctype": "Item Tax Template", "title": "_Test VAT 7% Template", "company": "_Test Company", "taxes": [ { "tax_type": "_Test Account VAT - _TC", "tax_rate": 7, }, { "tax_type": "_Test Account Service Tax - _TC", "tax_rate": 0, "not_applicable": 1, }, ], } ).insert(ignore_if_duplicate=True) template_19pct = frappe.get_doc( { "doctype": "Item Tax Template", "title": "_Test VAT 19% Template", "company": "_Test Company", "taxes": [ { "tax_type": "_Test Account VAT - _TC", "tax_rate": 0, "not_applicable": 1, }, { "tax_type": "_Test Account Service Tax - _TC", "tax_rate": 19, }, ], } ).insert(ignore_if_duplicate=True) self.doc.items[0].item_tax_template = template_7pct.name self.doc.append( "items", { "item_code": "_Test Item 2", "qty": 1, "rate": 100, "income_account": "Sales - _TC", "expense_account": "Cost of Goods Sold - _TC", "cost_center": "_Test Cost Center - _TC", "item_tax_template": template_19pct.name, }, ) self.doc.append( "taxes", { "charge_type": "On Net Total", "account_head": "_Test Account VAT - _TC", "cost_center": "_Test Cost Center - _TC", "description": "VAT 7%", "rate": 0, }, ) self.doc.append( "taxes", { "charge_type": "On Net Total", "account_head": "_Test Account Service Tax - _TC", "cost_center": "_Test Cost Center - _TC", "description": "VAT 19%", "rate": 0, }, ) self.doc.save() # VAT 7%: Only Item 1 contributes (Item 2 has not_applicable) self.assertEqual(self.doc.taxes[0].net_amount, 100.0) # Service Tax 19%: Only Item 2 contributes (Item 1 has not_applicable) self.assertEqual(self.doc.taxes[1].net_amount, 100.0) expected_values = [ { "item_row": self.doc.items[0].name, "tax_row": self.doc.taxes[0].name, "rate": 7.0, "amount": 7.0, "taxable_amount": 100.0, }, { "item_row": self.doc.items[1].name, "tax_row": self.doc.taxes[1].name, "rate": 19.0, "amount": 19.0, "taxable_amount": 100.0, }, ] actual_values = [ { "item_row": row.item_row, "tax_row": row.tax_row, "rate": row.rate, "amount": row.amount, "taxable_amount": row.taxable_amount, } for row in self.doc.item_wise_tax_details ] self.assertEqual(actual_values, expected_values)