feat: add check stackability for the shipping discount

Signed-off-by: vanpho93 <[email protected]>

packages/api-plugin-promotions-discounts/src/discountTypes/shipping/applyShippingDiscountToCart.js

@@ -1,4 +1,3 @@
-/* eslint-disable no-unused-vars */
 import { createRequire } from "module";
 import _ from "lodash";
 import Logger from "@reactioncommerce/logger";
@@ -7,6 +6,7 @@ import formatMoney from "../../utils/formatMoney.js";
 import getEligibleShipping from "../../utils/getEligibleIShipping.js";
 import calculateDiscountAmount from "../../utils/calculateDiscountAmount.js";
 import recalculateQuoteDiscount from "../../utils/recalculateQuoteDiscount.js";
+import checkShippingStackable from "./checkShippingStackable.js";
 
 const require = createRequire(import.meta.url);
 
@@ -137,8 +137,14 @@ export async function estimateShipmentQuoteDiscount(context, cart, params) {
     const canBeDiscounted = canBeApplyDiscountToShipping(shipmentQuote, promotion);
     if (!canBeDiscounted) continue;
 
+    const shippingDiscount = createDiscountRecord(params, item);
+
     if (!shipmentQuote.discounts) shipmentQuote.discounts = [];
-    shipmentQuote.discounts.push(createDiscountRecord(params, item));
+    // eslint-disable-next-line no-await-in-loop
+    const canStackable = await checkShippingStackable(context, shipmentQuote, shippingDiscount);
+    if (!canStackable) continue;
+
+    shipmentQuote.discounts.push(shippingDiscount);
 
     affectedItemsLength += 1;
     recalculateQuoteDiscount(context, shipmentQuote, actionParameters);

packages/api-plugin-promotions-discounts/src/discountTypes/shipping/applyShippingDiscountToCart.test.js

@@ -1,5 +1,8 @@
 import mockContext from "@reactioncommerce/api-utils/tests/mockContext.js";
 import * as applyShippingDiscountToCart from "./applyShippingDiscountToCart.js";
+import checkShippingStackable from "./checkShippingStackable.js";
+
+jest.mock("./checkShippingStackable.js", () => jest.fn());
 
 test("createDiscountRecord should create discount record", () => {
   const parameters = {
@@ -79,6 +82,7 @@ test("should apply shipping discount to cart", async () => {
   mockContext.discountCalculationMethods = {
     fixed: jest.fn().mockReturnValue(2)
   };
+  checkShippingStackable.mockReturnValue(true);
 
   const { cart: updatedCart, affected } = await applyShippingDiscountToCart.default(mockContext, parameters, cart);
 

packages/api-plugin-promotions-discounts/src/discountTypes/shipping/checkShippingStackable.js

@@ -0,0 +1,28 @@
+/* eslint-disable no-await-in-loop */
+import _ from "lodash";
+
+/**
+ * @summary check if a promotion is applicable to a cart
+ * @param {Object} context - The application context
+ * @param {Object} shipping - The cart we are trying to apply the promotion to
+ * @param {Object} discount - The promotion we are trying to apply
+ * @returns {Promise<Boolean>} - Whether the promotion is applicable to the shipping
+ */
+export default async function checkShippingStackable(context, shipping, discount) {
+  const { promotions } = context;
+  const stackabilityByKey = _.keyBy(promotions.stackabilities, "key");
+
+  for (const appliedDiscount of shipping.discounts) {
+    if (!appliedDiscount.stackability) continue;
+
+    const stackHandler = stackabilityByKey[discount.stackability.key];
+    const appliedStackHandler = stackabilityByKey[appliedDiscount.stackability.key];
+
+    const stackResult = await stackHandler.handler(context, null, { promotion: discount, appliedPromotion: appliedDiscount });
+    const appliedStackResult = await appliedStackHandler.handler(context, {}, { promotion: appliedDiscount, appliedPromotion: discount });
+
+    if (!stackResult || !appliedStackResult) return false;
+  }
+
+  return true;
+}

packages/api-plugin-promotions-discounts/src/discountTypes/shipping/checkShippingStackable.test.js

@@ -0,0 +1,45 @@
+import mockContext from "@reactioncommerce/api-utils/tests/mockContext.js";
+import checkShippingStackable from "./checkShippingStackable.js";
+
+test("should returns true if no the current discount is stackable", async () => {
+  const shipping = {
+    discounts: [
+      {
+        stackability: { key: "all" }
+      }
+    ]
+  };
+  const discount = {
+    stackability: { key: "all" }
+  };
+
+  mockContext.promotions = {
+    stackabilities: [{ key: "all", handler: () => true }]
+  };
+
+  const result = await checkShippingStackable(mockContext, shipping, discount);
+  expect(result).toBe(true);
+});
+
+test("should returns false if the current discount is not stackable", async () => {
+  const shipping = {
+    discounts: [
+      {
+        stackability: { key: "all" }
+      }
+    ]
+  };
+  const discount = {
+    stackability: { key: "none" }
+  };
+
+  mockContext.promotions = {
+    stackabilities: [
+      { key: "all", handler: () => true },
+      { key: "none", handler: () => false }
+    ]
+  };
+
+  const result = await checkShippingStackable(mockContext, shipping, discount);
+  expect(result).toBe(false);
+});