hospitality.gross-profit-menu

Imports name this capability’s declared dependencies, which fune builds next to it in your project; each one links to its page.

import { margin } from "./finance_margin.ts";  ← from finance.margin ^1.0.0 · built alongside by fune
import { removeVat } from "./finance_tax_remove_vat.ts";  ← from finance.tax.remove-vat ^1.0.0 · built alongside by fune
import { type Money } from "./money_amount.ts";  ← from money.amount ^1.0.0 · built alongside by fune
import { type MenuGrossProfit } from "./hospitality_gross_profit_menu_types.ts";

/**
 * Gross profit on a menu price.
 *
 * Hospitality GP is worked out on the price without VAT, because the VAT is
 * the tax authority's money, not the kitchen's: a 14.50 dish costing 3.50 at
 * 20% VAT is a 71.03% GP, not the 75.86% the VAT-inclusive price suggests.
 */
export function menuGrossProfit(cost: Money, menuPrice: Money, jurisdiction: string, category: string, onDate: string): MenuGrossProfit {
  if (cost.minor < 0) throw new RangeError(`cost must not be negative, received ${cost.minor}`);
  if (menuPrice.minor < 0) throw new RangeError(`menuPrice must not be negative, received ${menuPrice.minor}`);
  const vat = removeVat(menuPrice, jurisdiction, category, onDate);
  const breakdown = margin(cost, vat.net);
  const gp = breakdown.marginBasisPoints;
  return {
    menuPrice,
    vat: vat.tax,
    netPrice: vat.net,
    cost,
    grossProfit: breakdown.profit,
    gpBasisPoints: gp,
    costBasisPoints: gp === null ? null : 10000 - gp,
    vatRateBasisPoints: vat.basisPoints,
  };
}

Imports name this capability’s declared dependencies, which fune builds next to it in your project; each one links to its page.

import { roundDiv } from "./math_round_div.ts";  ← from math.round-div ^1.0.0 · built alongside by fune
import { type Money, money } from "./money_amount.ts";  ← from money.amount ^1.0.0 · built alongside by fune
import { markupPrice } from "./finance_markup_price.ts";  ← from finance.markup-price ^1.0.0 · built alongside by fune
import { addVat } from "./finance_tax_add_vat.ts";  ← from finance.tax.add-vat ^1.0.0 · built alongside by fune
import { menuGrossProfit } from "./hospitality_gross_profit_menu_menu_gross_profit.ts";  ← menuGrossProfit, another function of this group · built into the same file, even by a slim install
import { type MenuGrossProfit } from "./hospitality_gross_profit_menu_types.ts";

/**
 * The menu price that reaches a target GP.
 *
 * The net price is the smallest that makes the target on the VAT-exclusive
 * price (finance.markup-price, rounded up), VAT goes on top, and the menu
 * price is rounded up to the step a menu is printed in. Rounding only ever
 * goes up, so the GP returned is never below the target.
 */
export function menuPriceForGp(
  cost: Money,
  targetGpBasisPoints: number,
  priceStep: number,
  jurisdiction: string,
  category: string,
  onDate: string,
): MenuGrossProfit {
  if (!Number.isInteger(targetGpBasisPoints) || targetGpBasisPoints < 0 || targetGpBasisPoints > 9999) {
    throw new RangeError(`targetGpBasisPoints must be a whole number from 0 to 9999, received ${targetGpBasisPoints}`);
  }
  if (!Number.isInteger(priceStep) || priceStep < 1) throw new RangeError(`priceStep must be at least 1, received ${priceStep}`);
  if (cost.minor < 0) throw new RangeError(`cost must not be negative, received ${cost.minor}`);
  const net = markupPrice(cost, targetGpBasisPoints, "margin", "up");
  const gross = addVat(net, jurisdiction, category, onDate).gross;
  const menuPrice = money(roundDiv(gross.minor, priceStep, "up") * priceStep, gross.currency);
  return menuGrossProfit(cost, menuPrice, jurisdiction, category, onDate);
}