feat: enable HighPrecisionMoney (#365)

Support HighPrecisionMoney next to the default CentPrecisionMoney

Author: robertmoelker

.changeset/cold-phones-film.md

@@ -0,0 +1,5 @@
+---
+"@labdigital/commercetools-mock": minor
+---
+
+Add HighPrecisionMoney support

src/repositories/cart/actions.ts

@@ -52,6 +52,7 @@ import type { Writable } from "#src/types.ts";
 import type { UpdateHandlerInterface } from "../abstract.ts";
 import { AbstractUpdateHandler, type RepositoryContext } from "../abstract.ts";
 import {
+	calculateMoneyTotalCentAmount,
 	createAddress,
 	createCentPrecisionMoney,
 	createCustomFields,
@@ -183,6 +184,10 @@ export class CartUpdateHandler
 					`No valid price found for ${productId} for country ${resource.country} and currency ${currency}`,
 				);
 			}
+			const totalPrice = createCentPrecisionMoney({
+				currencyCode: price.value.currencyCode,
+				centAmount: calculateMoneyTotalCentAmount(price.value, quantity),
+			});
 			resource.lineItems.push({
 				id: uuidv4(),
 				key,
@@ -196,11 +201,7 @@ export class CartUpdateHandler
 				price: price,
 				taxedPricePortions: [],
 				perMethodTaxRate: [],
-				totalPrice: {
-					...price.value,
-					type: "centPrecision",
-					centAmount: price.value.centAmount * quantity,
-				},
+				totalPrice,
 				quantity,
 				discountedPricePerQuantity: [],
 				lineItemMode: "Standard",
@@ -427,8 +428,11 @@ export class CartUpdateHandler
 			}
 			customLineItem.quantity = quantity;
 			customLineItem.totalPrice = createCentPrecisionMoney({
-				...customLineItem.money,
-				centAmount: (customLineItem.money.centAmount ?? 0) * quantity,
+				currencyCode: customLineItem.money.currencyCode,
+				centAmount: calculateMoneyTotalCentAmount(
+					customLineItem.money,
+					quantity,
+				),
 			});
 		};
 
@@ -470,8 +474,11 @@ export class CartUpdateHandler
 			}
 			customLineItem.money = createTypedMoney(money);
 			customLineItem.totalPrice = createCentPrecisionMoney({
-				...money,
-				centAmount: (money.centAmount ?? 0) * customLineItem.quantity,
+				currencyCode: money.currencyCode,
+				centAmount: calculateMoneyTotalCentAmount(
+					money,
+					customLineItem.quantity,
+				),
 			});
 		};
 
@@ -608,7 +615,7 @@ export class CartUpdateHandler
 			shippingMethodName,
 			price: createCentPrecisionMoney(shippingRate.price),
 			shippingRate: {
-				price: createTypedMoney(shippingRate.price),
+				price: createCentPrecisionMoney(shippingRate.price),
 				tiers: [],
 			},
 			taxCategory: tax
@@ -798,7 +805,7 @@ export class CartUpdateHandler
 
 		const lineItemTotal = calculateLineItemTotalPrice(lineItem);
 		lineItem.totalPrice = createCentPrecisionMoney({
-			...lineItem.price!.value,
+			currencyCode: lineItem.price!.value.currencyCode,
 			centAmount: lineItemTotal,
 		});
 		resource.totalPrice.centAmount = calculateCartTotalPrice(resource);

src/repositories/cart/helpers.ts

@@ -11,6 +11,7 @@ import { v4 as uuidv4 } from "uuid";
 import { calculateTaxedPrice } from "#src/lib/tax.ts";
 import type { AbstractStorage } from "#src/storage/abstract.ts";
 import {
+	calculateMoneyTotalCentAmount,
 	createCentPrecisionMoney,
 	createCustomFields,
 	createTypedMoney,
@@ -40,8 +41,13 @@ export const selectPrice = ({
 	});
 };
 
-export const calculateLineItemTotalPrice = (lineItem: LineItem): number =>
-	lineItem.price?.value.centAmount * lineItem.quantity;
+export const calculateLineItemTotalPrice = (lineItem: LineItem): number => {
+	if (!lineItem.price?.value) {
+		return 0;
+	}
+
+	return calculateMoneyTotalCentAmount(lineItem.price.value, lineItem.quantity);
+};
 
 export const calculateCartTotalPrice = (cart: Cart): number => {
 	const lineItemsTotal = cart.lineItems.reduce(
@@ -83,8 +89,8 @@ export const createCustomLineItemFromDraft = (
 	}
 
 	const totalPrice = createCentPrecisionMoney({
-		...draft.money,
-		centAmount: (draft.money.centAmount ?? 0) * quantity,
+		currencyCode: draft.money.currencyCode,
+		centAmount: calculateMoneyTotalCentAmount(draft.money, quantity),
 	});
 
 	const taxedPrice = taxCategory

src/repositories/cart/index.ts

@@ -24,7 +24,12 @@ import {
 	AbstractResourceRepository,
 	type RepositoryContext,
 } from "../abstract.ts";
-import { createAddress, createCustomFields } from "../helpers.ts";
+import {
+	calculateMoneyTotalCentAmount,
+	createAddress,
+	createCentPrecisionMoney,
+	createCustomFields,
+} from "../helpers.ts";
 import { CartUpdateHandler } from "./actions.ts";
 import {
 	calculateCartTotalPrice,
@@ -238,6 +243,11 @@ export class CartRepository extends AbstractResourceRepository<"cart"> {
 			);
 		}
 
+		const totalPrice = createCentPrecisionMoney({
+			currencyCode: price.value.currencyCode,
+			centAmount: calculateMoneyTotalCentAmount(price.value, quant),
+		});
+
 		return {
 			id: uuidv4(),
 			productId: product.id,
@@ -247,12 +257,7 @@ export class CartRepository extends AbstractResourceRepository<"cart"> {
 			name: product.masterData.current.name,
 			variant,
 			price: price,
-			totalPrice: {
-				type: "centPrecision",
-				currencyCode: price.value.currencyCode,
-				fractionDigits: price.value.fractionDigits,
-				centAmount: price.value.centAmount * quant,
-			},
+			totalPrice,
 			taxedPricePortions: [],
 			perMethodTaxRate: [],
 			quantity: quant,

src/repositories/helpers.test.ts

@@ -1,7 +1,16 @@
-import type { BaseAddress } from "@commercetools/platform-sdk";
+import type {
+	BaseAddress,
+	HighPrecisionMoneyDraft,
+	Money,
+} from "@commercetools/platform-sdk";
 import { describe, expect, test } from "vitest";
 import { InMemoryStorage } from "#src/storage/index.ts";
-import { createAddress } from "./helpers.ts";
+import {
+	calculateCentAmountFromPreciseAmount,
+	calculateMoneyTotalCentAmount,
+	createAddress,
+	createHighPrecisionMoney,
+} from "./helpers.ts";
 
 describe("Helpers", () => {
 	const storage = new InMemoryStorage();
@@ -22,4 +31,106 @@ describe("Helpers", () => {
 			expect(result?.id).toMatch(/^[a-z0-9]{8}$/);
 		});
 	});
+
+	describe("calculateCentAmountFromPreciseAmount", () => {
+		test("rounds half even by default", () => {
+			const centAmount = calculateCentAmountFromPreciseAmount(1005, 3, "EUR");
+			expect(centAmount).toBe(100);
+		});
+
+		test("supports HalfUp and HalfDown rounding modes", () => {
+			const halfUp = calculateCentAmountFromPreciseAmount(
+				1005,
+				3,
+				"EUR",
+				"HalfUp",
+			);
+			const halfDown = calculateCentAmountFromPreciseAmount(
+				1005,
+				3,
+				"EUR",
+				"HalfDown",
+			);
+			expect(halfUp).toBe(101);
+			expect(halfDown).toBe(100);
+		});
+
+		test("uses currency fraction digits for conversion", () => {
+			const centAmount = calculateCentAmountFromPreciseAmount(1234, 2, "JPY");
+			expect(centAmount).toBe(12);
+		});
+	});
+
+	describe("createHighPrecisionMoney", () => {
+		test("computes centAmount when missing", () => {
+			const money = createHighPrecisionMoney({
+				type: "highPrecision",
+				currencyCode: "EUR",
+				fractionDigits: 3,
+				preciseAmount: 1015,
+			});
+
+			expect(money.type).toBe("highPrecision");
+			expect(money.centAmount).toBe(102);
+			expect(money.preciseAmount).toBe(1015);
+			expect(money.fractionDigits).toBe(3);
+		});
+
+		test("throws when preciseAmount is missing", () => {
+			expect(() =>
+				createHighPrecisionMoney({
+					type: "highPrecision",
+					currencyCode: "EUR",
+					fractionDigits: 3,
+				} as HighPrecisionMoneyDraft),
+			).toThrow("HighPrecisionMoney requires preciseAmount");
+		});
+
+		test("throws when fractionDigits is missing", () => {
+			expect(() =>
+				createHighPrecisionMoney({
+					type: "highPrecision",
+					currencyCode: "EUR",
+					preciseAmount: 1015,
+				} as HighPrecisionMoneyDraft),
+			).toThrow("HighPrecisionMoney requires fractionDigits");
+		});
+	});
+
+	describe("calculateMoneyTotalCentAmount", () => {
+		test("uses preciseAmount when available", () => {
+			const money: HighPrecisionMoneyDraft = {
+				type: "highPrecision",
+				currencyCode: "EUR",
+				fractionDigits: 5,
+				preciseAmount: 101499,
+				centAmount: 101,
+			};
+
+			const totalCentAmount = calculateMoneyTotalCentAmount(money, 2);
+			expect(totalCentAmount).toBe(203);
+		});
+
+		test("falls back to centAmount when preciseAmount is missing", () => {
+			const money: Money = {
+				currencyCode: "EUR",
+				centAmount: 123,
+			};
+
+			const totalCentAmount = calculateMoneyTotalCentAmount(money, 3);
+			expect(totalCentAmount).toBe(369);
+		});
+
+		test("supports rounding mode overrides", () => {
+			const money: HighPrecisionMoneyDraft = {
+				type: "highPrecision",
+				currencyCode: "EUR",
+				fractionDigits: 3,
+				preciseAmount: 1005,
+			};
+
+			const totalCentAmount = calculateMoneyTotalCentAmount(money, 1, "HalfUp");
+			expect(totalCentAmount).toBe(101);
+		});
+	});
 });