fix: correctly set tax rate on custom line items (#329)

Author: BramKaashoek

.changeset/twelve-icons-take.md

@@ -0,0 +1,5 @@
+---
+"@labdigital/commercetools-mock": patch
+---
+
+fix: implement tax rate on custom line items

src/repositories/cart/helpers.ts

@@ -150,7 +150,6 @@ export const createCustomLineItemFromDraft = (
 			)
 		: undefined;
 
-	// Get the tax category to calculate taxed price
 	let taxCategory: TaxCategory | undefined = undefined;
 	if (taxCategoryRef) {
 		try {
@@ -167,7 +166,6 @@ export const createCustomLineItemFromDraft = (
 		centAmount: (draft.money.centAmount ?? 0) * quantity,
 	});
 
-	// Calculate taxed price if tax category is available
 	const taxedPrice = taxCategory
 		? calculateTaxedPrice(
 				totalPrice.centAmount,
@@ -177,6 +175,12 @@ export const createCustomLineItemFromDraft = (
 			)
 		: undefined;
 
+	const taxRate = taxCategory
+		? taxCategory.rates.find(
+				(rate) => !rate.country || rate.country === country,
+			) || taxCategory.rates[0]
+		: undefined;
+
 	return {
 		id: uuidv4(),
 		key: draft.key,
@@ -186,6 +190,7 @@ export const createCustomLineItemFromDraft = (
 		quantity: draft.quantity ?? 1,
 		state: [],
 		taxCategory: taxCategoryRef,
+		taxRate,
 		taxedPrice,
 		custom: createCustomFields(draft.custom, projectKey, storage),
 		discountedPricePerQuantity: [],

src/repositories/cart/index.test.ts

@@ -293,5 +293,10 @@ describe("Cart repository", () => {
 		expect(customLineItem.taxedPrice?.totalTax?.centAmount).toBe(210);
 		expect(customLineItem.taxedPrice?.taxPortions).toHaveLength(1);
 		expect(customLineItem.taxedPrice?.taxPortions[0].rate).toBe(0.21);
+		expect(customLineItem.taxRate).toBeDefined();
+		expect(customLineItem.taxRate?.amount).toBe(0.21);
+		expect(customLineItem.taxRate?.name).toBe("Standard VAT");
+		expect(customLineItem.taxRate?.includedInPrice).toBe(false);
+		expect(customLineItem.taxRate?.country).toBe("NL");
 	});
 });

src/services/cart.test.ts

@@ -1399,6 +1399,8 @@ describe("Cart Update Actions", () => {
 		expect(customLineItem.totalPrice.centAmount).toBe(1000);
 		expect(customLineItem.taxCategory.id).toBe(taxCategory.id);
 		expect(customLineItem.taxedPrice).toBeDefined();
+		expect(customLineItem.taxRate).toBeDefined();
+		expect(customLineItem.taxRate.amount).toBe(0.21);
 		expect(customLineItem.id).toBeDefined();
 		expect(customLineItem.custom).toBeDefined();
 		expect(customLineItem.custom.fields.description).toBe(