fix(taxes): improve tax calculation accuracy and update test assertions

(cherry picked from commit a18196f584)
This commit is contained in:
Smit Vora
2026-03-30 19:37:59 +05:30
committed by Mergify
parent 6689b17b88
commit 6ad5e89607
2 changed files with 25 additions and 11 deletions

View File

@@ -285,6 +285,13 @@ class calculate_taxes_and_totals:
self.doc._item_wise_tax_details = item_wise_tax_details
self.doc.item_wise_tax_details = []
for tax in self.doc.get("taxes"):
if not tax.get("dont_recompute_tax"):
tax._running_txn_tax_total = 0.0
tax._running_base_tax_total = 0.0
tax._running_txn_taxable_total = 0.0
tax._running_base_taxable_total = 0.0
def determine_exclusive_rate(self):
if not any(cint(tax.included_in_print_rate) for tax in self.doc.get("taxes")):
return
@@ -521,8 +528,7 @@ class calculate_taxes_and_totals:
actual_breakup = tax._total_tax_breakup
diff = flt(expected_amount - actual_breakup, 5)
# TODO: fix rounding difference issues
if abs(diff) <= 1:
if abs(diff) <= 0.5:
detail_row = self.doc._item_wise_tax_details[last_idx]
detail_row["amount"] = flt(detail_row["amount"] + diff, 5)
@@ -597,14 +603,25 @@ class calculate_taxes_and_totals:
def set_item_wise_tax(self, item, tax, tax_rate, current_tax_amount, current_net_amount):
# store tax breakup for each item
multiplier = -1 if tax.get("add_deduct_tax") == "Deduct" else 1
item_wise_tax_amount = flt(
current_tax_amount * self.doc.conversion_rate * multiplier, tax.precision("tax_amount")
# Error diffusion: derive each item's base amount as a delta of the running cumulative total
# so the sum always equals base_tax_amount_after_discount_amount.
tax._running_txn_tax_total += current_tax_amount * multiplier
new_base_tax_total = flt(
flt(tax._running_txn_tax_total, tax.precision("tax_amount")) * self.doc.conversion_rate,
tax.precision("base_tax_amount"),
)
item_wise_tax_amount = new_base_tax_total - tax._running_base_tax_total
tax._running_base_tax_total = new_base_tax_total
if tax.charge_type != "On Item Quantity":
item_wise_taxable_amount = flt(
current_net_amount * self.doc.conversion_rate * multiplier, tax.precision("tax_amount")
tax._running_txn_taxable_total += current_net_amount * multiplier
new_base_taxable_total = flt(
flt(tax._running_txn_taxable_total, tax.precision("net_amount")) * self.doc.conversion_rate,
tax.precision("base_net_amount"),
)
item_wise_taxable_amount = new_base_taxable_total - tax._running_base_taxable_total
tax._running_base_taxable_total = new_base_taxable_total
else:
item_wise_taxable_amount = 0.0

View File

@@ -179,14 +179,11 @@ class TestTaxesAndTotals(ERPNextTestSuite):
details_by_tax = {}
for detail in doc.item_wise_tax_details:
bucket = details_by_tax.setdefault(detail.tax_row, {"amount": 0.0, "taxable_amount": 0.0})
bucket = details_by_tax.setdefault(detail.tax_row, {"amount": 0.0})
bucket["amount"] += detail.amount
for tax in doc.taxes:
detail_totals = details_by_tax[tax.name]
self.assertAlmostEqual(
detail_totals["amount"], tax.base_tax_amount_after_discount_amount, places=2
)
self.assertEqual(details_by_tax[tax.name]["amount"], tax.base_tax_amount_after_discount_amount)
def test_item_wise_tax_detail_with_multi_currency_with_single_item(self):
"""