fix(discounts): Stop reporting invalid coupons as applied while a campaign is active

packages/apps/discounts/lib-mjs/apply-discount.mjs

@@ -517,9 +517,11 @@ export default async ({ params, application }) => {
   });
 
   const discountRules = getValidDiscountRules(config.discount_rules, params);
+  let isCouponFound = false;
   if (discountRules.length) {
     const { discountRule, discountMatchEnum } = matchDiscountRule(discountRules, params);
     if (discountRule) {
+      isCouponFound = discountMatchEnum === 'COUPON';
       const {
         valid: isValidByItems,
         items: filteredItems,
@@ -679,11 +681,36 @@ export default async ({ params, application }) => {
             };
           }
         }
+      } else if (isCouponFound && discountRule.discount.min_amount > checkAmount) {
+        // coupon exists but cart is still under the minimum amount
+        const missingAmount = ecomUtils.formatMoney(
+          discountRule.discount.min_amount - checkAmount,
+          params.currency_id,
+          params.lang,
+        );
+        response.invalid_coupon_message = params.lang === 'pt_br'
+          ? `Adicione mais ${missingAmount} ao carrinho para usar este cupom.`
+          : `Add ${missingAmount} more to the cart to use this coupon.`;
       }
     }
   }
 
   addFreebies();
+  if (params.discount_coupon && !isCouponFound) {
+    const couponCode = params.discount_coupon.toUpperCase();
+    const isFreebieCoupon = Array.isArray(config.freebies_rules)
+      && config.freebies_rules.some((rule) => {
+        return rule.freebie_coupon?.toUpperCase() === couponCode
+          && validateDateRange(rule)
+          && validateCustomerId(rule, params);
+      });
+    if (!isFreebieCoupon) {
+      // kit/freebie campaigns may still be applied, but not the typed coupon
+      response.invalid_coupon_message = params.lang === 'pt_br'
+        ? 'O cupom de desconto inserido é inválido.'
+        : 'Discount coupon entered is invalid.';
+    }
+  }
   // response with no error nor discount applied
   return respondSuccess();
 };

packages/apps/discounts/tests/invalid-coupon.test.mjs

@@ -0,0 +1,112 @@
+import assert from 'node:assert';
+import test, { describe } from 'node:test';
+import applyDiscount from '../lib-mjs/apply-discount.mjs';
+
+/*
+Com uma campanha de kit ativa (ex.: leve 4 pague 3) a resposta sempre traz
+`discount_rule`, e o DiscountApplier da loja trata qualquer desconto com cupom
+digitado como "Cupom de desconto aplicado com sucesso." a menos que o app
+devolva `invalid_coupon_message`. O cupom inválido ainda era gravado no
+carrinho como se tivesse sido aceito.
+*/
+const categoryId = '68371790f3c4f8399c4948c2';
+const items = [70, 70, 60, 80].map((price, i) => ({
+  product_id: `00000000000000000000000${i + 1}`,
+  sku: `SKU-${i + 1}`,
+  name: `Produto ${i + 1}`,
+  quantity: 1,
+  price,
+  categories: [{ _id: categoryId, name: 'Leve 4 pague 3' }],
+}));
+
+const getApplication = () => ({
+  data: {
+    product_kit_discounts: [{
+      label: 'leve4pague3',
+      category_ids: [categoryId],
+      min_quantity: 4,
+      discount_lowest_price: true,
+      discount: { apply_at: 'total' },
+    }],
+    freebies_rules: [{
+      label: 'brinde',
+      freebie_coupon: 'BRINDE',
+      product_ids: ['683748d6f3c4f8399c499b51'],
+      min_subtotal: 1,
+    }],
+  },
+  hidden_data: {
+    discount_rules: [{
+      discount_coupon: 'ANIVERSARIO',
+      case_insensitive: true,
+      discount: { apply_at: 'total', type: 'percentage', value: 10 },
+    }, {
+      discount_coupon: 'VENCIDO',
+      date_range: { end: '2020-01-01T00:00:00.000Z' },
+      discount: { apply_at: 'total', type: 'fixed', value: 15 },
+    }, {
+      discount_coupon: 'MINIMO500',
+      discount: {
+        apply_at: 'total',
+        type: 'fixed',
+        value: 30,
+        min_amount: 500,
+      },
+    }],
+  },
+});
+
+const run = (discountCoupon) => applyDiscount({
+  params: {
+    lang: 'pt_br',
+    currency_id: 'BRL',
+    amount: { subtotal: 280, total: 280, discount: 0 },
+    items,
+    discount_coupon: discountCoupon,
+  },
+  application: getApplication(),
+});
+
+describe('Cupom digitado com campanha de kit ativa', () => {
+  test('cupom inexistente mantém o kit e avisa que o cupom é inválido', async () => {
+    const response = await run('testealeatorio');
+    assert.deepStrictEqual(response.discount_rule.extra_discount, { value: 60, flags: ['KIT-1'] });
+    assert.strictEqual(response.invalid_coupon_message, 'O cupom de desconto inserido é inválido.');
+  });
+
+  test('cupom vencido é tratado como inválido', async () => {
+    const response = await run('VENCIDO');
+    assert.strictEqual(response.discount_rule.extra_discount.value, 60);
+    assert.strictEqual(response.invalid_coupon_message, 'O cupom de desconto inserido é inválido.');
+  });
+
+  test('cupom abaixo do valor mínimo informa quanto falta', async () => {
+    const response = await run('MINIMO500');
+    assert.strictEqual(response.discount_rule.extra_discount.value, 60);
+    assert.strictEqual(
+      response.invalid_coupon_message?.replace(/\s/g, ' '),
+      'Adicione mais R$ 220,00 ao carrinho para usar este cupom.',
+    );
+  });
+
+  test('cupom válido soma ao kit sem mensagem de erro', async () => {
+    const response = await run('aniversario');
+    assert.deepStrictEqual(response.discount_rule.extra_discount, {
+      value: 82,
+      flags: ['KIT-1', 'COUPON'],
+    });
+    assert.strictEqual(response.invalid_coupon_message, undefined);
+  });
+
+  test('cupom de brinde não é tratado como inválido', async () => {
+    const response = await run('brinde');
+    assert.deepStrictEqual(response.freebie_product_ids, ['683748d6f3c4f8399c499b51']);
+    assert.strictEqual(response.invalid_coupon_message, undefined);
+  });
+
+  test('sem cupom não há mensagem de cupom', async () => {
+    const response = await run(undefined);
+    assert.strictEqual(response.discount_rule.extra_discount.value, 60);
+    assert.strictEqual(response.invalid_coupon_message, undefined);
+  });
+});