Imports name this capability’s declared dependencies, which fune builds next to it in your project; each one links to its page.
import re
from .math_round_div import round_div ← from math.round-div ^1.0.0 · built alongside by fune
from .money_amount import Money, money ← from money.amount ^1.0.0 · built alongside by fune
from .retail_sales_tax_us_data import STATE_RATES, STATE_RATES_HISTORY ← this capability’s own data, compiled from data/state-rates.json into the same file by fune build
from .retail_sales_tax_us_types import UsSalesTax
_ISO_DATE = re.compile(r"[0-9]{4}-[0-9]{2}-[0-9]{2}")
def _state_rate(state: str, on_date: str) -> int:
if not any(r.state == state for r in STATE_RATES):
raise ValueError('unknown US state "%s"' % (state,))
best = None
for r in STATE_RATES:
if r.state != state or on_date < r.valid_from or (r.valid_to is not None and on_date > r.valid_to):
continue
if best is None or r.valid_from > best.valid_from:
best = r
if best is not None:
return best.rate_per_million
if STATE_RATES_HISTORY != "full":
earliest = None
for r in STATE_RATES:
if r.state == state and (earliest is None or r.valid_from < earliest):
earliest = r.valid_from
if earliest is not None and on_date < earliest:
raise ValueError(
"no sales tax rate for %s on %s: this build was installed with history=%s, "
"so it only carries rates from %s. Reinstall with history=full for older sales."
% (state, on_date, STATE_RATES_HISTORY, earliest)
)
raise ValueError("no sales tax rate for %s on %s" % (state, on_date))
def sales_tax_us(amount: Money, state: str, local_rate_per_million: int, on_date: str) -> UsSalesTax:
"""US sales tax: the state's base rate on the date of sale plus the
caller's local rate, applied once and rounded half up to the cent.
"""
if not isinstance(on_date, str) or not _ISO_DATE.fullmatch(on_date):
raise ValueError('onDate must be an ISO date (YYYY-MM-DD), received "%s"' % (on_date,))
if amount.currency != "USD":
raise ValueError("US sales tax is charged in USD, received %s" % amount.currency)
if (
isinstance(local_rate_per_million, bool)
or not isinstance(local_rate_per_million, int)
or local_rate_per_million < 0
or local_rate_per_million >= 1000000
):
raise ValueError("localRatePerMillion must be from 0 to 999999, received %r" % (local_rate_per_million,))
state_rate_per_million = _state_rate(state, on_date)
combined = state_rate_per_million + local_rate_per_million
tax = money(round_div(amount.minor * combined, 1000000, "half-up"), "USD")
return UsSalesTax(
state=state,
state_rate_per_million=state_rate_per_million,
local_rate_per_million=local_rate_per_million,
combined_rate_per_million=combined,
taxable=amount,
tax=tax,
total=money(amount.minor + tax.minor, "USD"),
)