feat(cart): add daffCartGetItemTotalDiscount (#2797)

libs/cart/src/helpers/get-affected-item.spec.ts

@@ -0,0 +1,41 @@
+import { TestBed } from '@angular/core/testing';
+
+import { DaffCartItem } from '@daffodil/cart';
+import { DaffCartItemFactory } from '@daffodil/cart/testing';
+
+import { daffCartGetAffectedItems } from './get-affected-item';
+
+describe('@daffodil/cart | daffCartGetAffectedItems', () => {
+  let cartItemFactory: DaffCartItemFactory;
+  let newItems: Array<DaffCartItem>;
+  let oldItems: Array<DaffCartItem>;
+  let result: Array<DaffCartItem['id']>;
+
+  beforeEach(() => {
+    cartItemFactory = TestBed.inject(DaffCartItemFactory);
+    oldItems = cartItemFactory.createMany(2);
+    newItems = [
+      {
+        ...oldItems[0],
+        qty: oldItems[0].qty + 1,
+      },
+      oldItems[1],
+      cartItemFactory.create({
+        id: `${oldItems[0].id}${oldItems[1].id}`,
+      }),
+    ];
+    result = daffCartGetAffectedItems(oldItems, newItems);
+  });
+
+  it('should return updated cart items', () => {
+    expect(result).toContain(newItems[0].id);
+  });
+
+  it('should return added cart items', () => {
+    expect(result).toContain(newItems[2].id);
+  });
+
+  it('should not return unchanged cart items', () => {
+    expect(result).not.toContain(newItems[1].id);
+  });
+});

libs/cart/src/helpers/get-item-total-discount.spec.ts

@@ -0,0 +1,31 @@
+import { TestBed } from '@angular/core/testing';
+
+import { DaffCartItem } from '@daffodil/cart';
+import { DaffCartItemFactory } from '@daffodil/cart/testing';
+
+import { daffCartGetItemTotalDiscount } from './get-item-total-discount';
+
+describe('@daffodil/cart | daffCartGetItemTotalDiscount', () => {
+  let cartItemFactory: DaffCartItemFactory;
+  let cartItem: DaffCartItem;
+
+  beforeEach(() => {
+    cartItemFactory = TestBed.inject(DaffCartItemFactory);
+    cartItem = cartItemFactory.create();
+  });
+
+  it('should return the summed value of all the item\'s discounts', () => {
+    cartItem.discounts = [
+      {
+        amount: 1,
+        label: 'discount1',
+      },
+      {
+        amount: 2,
+        label: 'discount2',
+      },
+    ];
+
+    expect(daffCartGetItemTotalDiscount(cartItem)).toEqual(3);
+  });
+});

libs/cart/src/helpers/get-item-total-discount.ts

@@ -0,0 +1,10 @@
+import { daffAdd } from '@daffodil/core';
+
+import { DaffCartItem } from '../models/public_api';
+
+/**
+ * Sums the discount amounts of the cart item.
+ */
+export function daffCartGetItemTotalDiscount(item: DaffCartItem): number {
+  return item?.discounts?.reduce((acc, { amount }) => daffAdd(acc, amount), 0) || 0;
+}

libs/cart/src/helpers/input-to-item-transform.spec.ts

@@ -0,0 +1,33 @@
+import {
+  DaffCartItem,
+  DaffCartItemInput,
+  DaffCartItemInputType,
+} from '@daffodil/cart';
+
+import { daffCartItemInputToItemTransform } from './input-to-item-transform';
+
+describe('@daffodil/cart | daffCartItemInputToItemTransform', () => {
+  let cartItemInput: DaffCartItemInput;
+  let result: DaffCartItem;
+
+  beforeEach(() => {
+    cartItemInput = {
+      type: DaffCartItemInputType.Simple,
+      qty: 2,
+      productId: 'productId',
+    };
+    result = daffCartItemInputToItemTransform(cartItemInput);
+  });
+
+  it('should set type', () => {
+    expect(result.type).toEqual(cartItemInput.type);
+  });
+
+  it('should set product ID', () => {
+    expect(result.product_id).toEqual(cartItemInput.productId);
+  });
+
+  it('should set qty', () => {
+    expect(result.qty).toEqual(cartItemInput.qty);
+  });
+});

libs/cart/src/helpers/input-to-item-transform.ts

@@ -3,6 +3,9 @@ import {
   DaffCartItemInput,
 } from '../models/public_api';
 
+/**
+ * Creates a stub cart item from the cart item input.
+ */
 export const daffCartItemInputToItemTransform = (input: DaffCartItemInput): DaffCartItem => ({
   type: input.type,
   product_id: input.productId,

libs/cart/src/helpers/public_api.ts

@@ -1,2 +1,3 @@
 export * from './get-affected-item';
 export * from './input-to-item-transform';
+export * from './get-item-total-discount';