From 37492799b784a714aa0c005e66c1286bc1ff3108 Mon Sep 17 00:00:00 2001
From: Mateus Nardo <m.nardo@epilot.cloud>
Date: Tue, 9 Jan 2024 12:03:49 +0100
Subject: [PATCH] fix: fix nontaxable prices

---
 src/__tests__/fixtures/price.samples.ts | 29 ++++++++++++++++
 src/pricing.test.ts                     | 44 +++++++++++++++++++++++++
 src/pricing.ts                          |  4 +--
 3 files changed, 75 insertions(+), 2 deletions(-)

diff --git a/src/__tests__/fixtures/price.samples.ts b/src/__tests__/fixtures/price.samples.ts
index e3e8268..092b2e6 100644
--- a/src/__tests__/fixtures/price.samples.ts
+++ b/src/__tests__/fixtures/price.samples.ts
@@ -205,6 +205,35 @@ export const priceItemNonTaxable: PriceItemDto = {
   pricing_model: 'per_unit',
 };
 
+export const priceItemNonTaxable2: PriceItemDto = {
+  quantity: 1,
+  product_id: 'prod-id#12325',
+  price_id: 'price#4',
+  _price: {
+    _id: 'price#4',
+    unit_amount: 2000,
+    unit_amount_currency: 'EUR',
+    unit_amount_decimal: '20.00',
+    type: 'recurring',
+    billing_period: 'monthly',
+    billing_duration_amount: 1,
+    billing_duration_unit: 'years',
+    notice_time_amount: 1,
+    notice_time_unit: 'months',
+    termination_time_amount: 2,
+    termination_time_unit: 'weeks',
+    renewal_duration_amount: 1,
+    renewal_duration_unit: 'years',
+    tax: null!,
+    is_tax_inclusive: true,
+    description: 'Winter Lease 2',
+    _title: 'Winter Lease 2',
+    pricing_model: 'per_unit',
+  },
+  _product: {},
+  pricing_model: 'per_unit',
+};
+
 export const compositePrice: CompositePriceItemDto = {
   price_id: 'price#4',
   product_id: 'prod-id#1234',
diff --git a/src/pricing.test.ts b/src/pricing.test.ts
index 8ccf64e..38ee477 100644
--- a/src/pricing.test.ts
+++ b/src/pricing.test.ts
@@ -106,6 +106,50 @@ describe('computeAggregatedAndPriceTotals', () => {
       );
     });
 
+    it('should return the right result when multiple prices are nontaxable', () => {
+      const priceItems = [samples.priceItemNonTaxable, samples.priceItemNonTaxable2];
+
+      const result = computeAggregatedAndPriceTotals(priceItems);
+
+      expect(result).toEqual(
+        expect.objectContaining({
+          amount_subtotal: 3000,
+          amount_total: 3000,
+          items: expect.arrayContaining([
+            expect.objectContaining({
+              amount_subtotal: 1000,
+              amount_total: 1000,
+              unit_amount_decimal: '10.00',
+              unit_amount_gross: 1000,
+              unit_amount_net: 1000,
+              taxes: [
+                {
+                  amount: 0,
+                  rate: 'nontaxable',
+                  rateValue: 0,
+                },
+              ],
+            }),
+            expect.objectContaining({
+              amount_subtotal: 2000,
+              amount_total: 2000,
+              unit_amount_decimal: '20.00',
+              unit_amount_gross: 2000,
+              unit_amount_net: 2000,
+              taxes: [
+                {
+                  amount: 0,
+                  rate: 'nontaxable',
+                  rateValue: 0,
+                },
+              ],
+            }),
+          ]),
+          total_details: expect.objectContaining({ amount_tax: 0 }),
+        }),
+      );
+    });
+
     it('should return the right result when quantity=0', () => {
       const priceItems = [{ ...samples.priceItem1, quantity: 0 }];
 
diff --git a/src/pricing.ts b/src/pricing.ts
index 5c871cd..b999294 100644
--- a/src/pricing.ts
+++ b/src/pricing.ts
@@ -438,7 +438,7 @@ const recomputeDetailTotals = (details: PricingDetails, price: Price, priceItemT
     recurrence.amount_tax = taxAmount.add(priceTax).getAmount();
   }
 
-  const recurrenceTax = !tax && itemTax ? taxes.at(-1) : tax;
+  const recurrenceTax = !tax && itemTax ? taxes?.[taxes?.length - 1] : tax;
 
   if (!recurrenceByTax) {
     const type = price?.type || priceItemToAppend?.type;
@@ -449,7 +449,7 @@ const recomputeDetailTotals = (details: PricingDetails, price: Price, priceItemT
       amount_total: priceTotal.getAmount(),
       amount_subtotal: priceSubtotal.getAmount(),
       amount_tax: priceTax.getAmount(),
-      tax: recurrenceTax,
+      tax: recurrenceTax ?? { amount: 0, rate: 'nontaxable', rateValue: 0, tax: { rate: 0 } },
     });
   } else {
     const totalAmount = d(recurrenceByTax.amount_total);