Replaced aggregate with entity and methods

Author: oskardudycz

samples/unwrapping_onion/src/unpeeled/ecommerce/shoppingCarts/application/mappers/customerShoppingHistoryMapper.ts

@@ -5,10 +5,16 @@ import { QueryBus } from '#core/queries';
 import { GetShoppingCartById } from 'src/unpeeled/ecommerce/shoppingCarts/application/queries/getShoppingCartById';
 import { assertNotEmptyString, assertPositiveNumber } from '#core/validation';
 import { AddProductItemToShoppingCartRequest } from 'src/unpeeled/ecommerce/shoppingCarts/requests/addProductItemToShoppingCartRequest';
-import { ProductItem } from 'src/unpeeled/ecommerce/shoppingCarts/common/productItem';
+import { ProductItem } from 'src/unpeeled/ecommerce/shoppingCarts/productItems/productItem';
 import { RemoveProductItemFromShoppingCartRequest } from 'src/unpeeled/ecommerce/shoppingCarts/requests/removeProductItemFromShoppingCartRequest.ts';
 import { GetCustomerShoppingHistory } from 'src/unpeeled/ecommerce/shoppingCarts/application/queries/getCustomerShoppingHistory';
-import { ShoppingCart } from 'src/unpeeled/ecommerce/shoppingCarts';
+import {
+  addProductItem as addProductItemToShoppingCart,
+  confirm as confirmShoppingCart,
+  open as openShoppingCart,
+  removeProductItem as removeProductItemFromShoppingCart,
+  ShoppingCart,
+} from 'src/unpeeled/ecommerce/shoppingCarts';
 import { EventBus } from '#core/events';
 import { ShoppingCartModel } from '../models/shoppingCart';
 import { Collection, MongoClient } from 'mongodb';
@@ -64,7 +70,7 @@ export class ShoppingCartController {
         },
       };
 
-      const event = ShoppingCart.open(
+      const event = openShoppingCart(
         command.data.shoppingCartId,
         command.data.customerId
       );
@@ -95,12 +101,15 @@ export class ShoppingCartController {
           ),
         },
       };
-      const aggregate = await getShoppingCart(
+      const cart = await getShoppingCart(
         this.carts,
         command.data.shoppingCartId
       );
 
-      const event = aggregate.addProductItem(command.data.productItem);
+      const event = addProductItemToShoppingCart(
+        cart,
+        command.data.productItem
+      );
 
       await store(this.carts, event);
       await this.eventBus.publish(event);
@@ -128,12 +137,15 @@ export class ShoppingCartController {
           ),
         },
       };
-      const aggregate = await getShoppingCart(
+      const cart = await getShoppingCart(
         this.carts,
         command.data.shoppingCartId
       );
 
-      const event = aggregate.removeProductItem(command.data.productItem);
+      const event = removeProductItemFromShoppingCart(
+        cart,
+        command.data.productItem
+      );
 
       await store(this.carts, event);
       await this.eventBus.publish(event);
@@ -157,12 +169,12 @@ export class ShoppingCartController {
           shoppingCartId: assertNotEmptyString(request.params.shoppingCartId),
         },
       };
-      const aggregate = await getShoppingCart(
+      const cart = await getShoppingCart(
         this.carts,
         command.data.shoppingCartId
       );
 
-      const event = aggregate.confirm();
+      const event = confirmShoppingCart(cart);
 
       await store(this.carts, event);
       await this.eventBus.publish(event);

samples/unwrapping_onion/src/unpeeled/ecommerce/shoppingCarts/controllers/shoppingCartController.ts

@@ -1,85 +1,85 @@
-import { ProductItem } from 'src/unpeeled/ecommerce/shoppingCarts/common/productItem';
+import { ProductItem } from 'src/unpeeled/ecommerce/shoppingCarts/productItems/productItem';
 import {
   ProductItemAddedToShoppingCart,
   ProductItemRemovedFromShoppingCart,
   ShoppingCartConfirmed,
   ShoppingCartOpened,
 } from './events';
 
-export class ShoppingCart {
-  public constructor(
-    public id: string,
-    public status: string,
-    public productItems: Map<string, number>,
-    public revision: number
-  ) {}
+export type ShoppingCart = Readonly<{
+  id: string;
+  status: string;
+  productItems: Map<string, number>;
+  revision: number;
+}>;
 
-  public static open(id: string, customerId: string): ShoppingCartOpened {
-    return {
-      type: 'shopping-cart-opened',
-      data: {
-        shoppingCartId: id,
-        customerId,
-        openedAt: new Date(),
-      },
-    };
+export const open = (id: string, customerId: string): ShoppingCartOpened => {
+  return {
+    type: 'shopping-cart-opened',
+    data: {
+      shoppingCartId: id,
+      customerId,
+      openedAt: new Date(),
+    },
+  };
+};
+
+export const addProductItem = (
+  cart: ShoppingCart,
+  newProductItem: ProductItem
+): ProductItemAddedToShoppingCart => {
+  if (cart.status !== ShoppingCartStatus.Opened) {
+    throw Error('Cannot add product to not opened shopping cart');
   }
 
-  public addProductItem(
-    newProductItem: ProductItem
-  ): ProductItemAddedToShoppingCart {
-    if (this.status !== ShoppingCartStatus.Opened) {
-      throw Error('Cannot add product to not opened shopping cart');
-    }
+  return {
+    type: 'product-item-added-to-shopping-cart',
+    data: {
+      shoppingCartId: cart.id,
+      productItem: newProductItem,
+      addedAt: new Date(),
+    },
+  };
+};
 
-    return {
-      type: 'product-item-added-to-shopping-cart',
-      data: {
-        shoppingCartId: this.id,
-        productItem: newProductItem,
-        addedAt: new Date(),
-      },
-    };
+export const removeProductItem = (
+  cart: ShoppingCart,
+  productItemToRemove: ProductItem
+): ProductItemRemovedFromShoppingCart => {
+  if (cart.status !== ShoppingCartStatus.Opened) {
+    throw Error('Cannot remove product from not opened shopping cart');
   }
 
-  public removeProductItem(
-    productItemToRemove: ProductItem
-  ): ProductItemRemovedFromShoppingCart {
-    if (this.status !== ShoppingCartStatus.Opened) {
-      throw Error('Cannot remove product from not opened shopping cart');
-    }
-
-    const { productId, quantity } = productItemToRemove;
+  const { productId, quantity } = productItemToRemove;
 
-    const currentQuantity = this.productItems.get(productId);
+  const currentQuantity = cart.productItems.get(productId);
 
-    const newQuantity = (currentQuantity ?? 0) - quantity;
+  const newQuantity = (currentQuantity ?? 0) - quantity;
 
-    if (newQuantity < 0) throw new Error('Product Item not found');
+  if (newQuantity < 0) throw new Error('Product Item not found');
 
-    return {
-      type: 'product-item-removed-from-shopping-cart',
-      data: {
-        shoppingCartId: this.id,
-        productItem: productItemToRemove,
-        removedAt: new Date(),
-      },
-    };
-  }
+  return {
+    type: 'product-item-removed-from-shopping-cart',
+    data: {
+      shoppingCartId: cart.id,
+      productItem: productItemToRemove,
+      removedAt: new Date(),
+    },
+  };
+};
 
-  public confirm(): ShoppingCartConfirmed {
-    if (this.status !== ShoppingCartStatus.Opened) {
-      throw Error('Cannot confirm to not opened shopping cart');
-    }
-    return {
-      type: 'shopping-cart-confirmed',
-      data: {
-        shoppingCartId: this.id,
-        confirmedAt: new Date(),
-      },
-    };
+export const confirm = (cart: ShoppingCart): ShoppingCartConfirmed => {
+  if (cart.status !== ShoppingCartStatus.Opened) {
+    throw Error('Cannot confirm to not opened shopping cart');
   }
-}
+  return {
+    type: 'shopping-cart-confirmed',
+    data: {
+      shoppingCartId: cart.id,
+      confirmedAt: new Date(),
+    },
+  };
+};
 
 export const ShoppingCartStatus = {
   Opened: 'Opened',

samples/unwrapping_onion/src/unpeeled/ecommerce/shoppingCarts/index.ts

@@ -1,5 +1,5 @@
 import { ObjectId } from 'mongodb';
-import { ProductItem } from 'src/unpeeled/ecommerce/shoppingCarts/common/productItem';
+import { ProductItem } from 'src/unpeeled/ecommerce/shoppingCarts/productItems/productItem';
 
 export class ShoppingCartModel {
   constructor(

samples/unwrapping_onion/src/unpeeled/ecommerce/shoppingCarts/models/shoppingCart.ts

@@ -11,12 +11,14 @@ export const getShoppingCart = async (
 ): Promise<ShoppingCart> => {
   const model = await getById(carts, id);
 
-  return new ShoppingCart(
-    model._id.toHexString(),
-    model.status,
-    new Map(model.productItems.map((p) => [p.productId, p.quantity])),
-    model.revision
-  );
+  return {
+    id: model._id.toHexString(),
+    status: model.status,
+    productItems: new Map(
+      model.productItems.map((p) => [p.productId, p.quantity])
+    ),
+    revision: model.revision,
+  };
 };
 
 export const findAllByCustomerId = async (